Anyone working on a tape file system ?
Mubashir Cheema
I was wondering if anyone is working on a tape file system. It
would be great to have an 8GB drive, well lots of them since those
4mm 8GB tapes are cheap ($10 a piece, I think).
Mubashir Cheema
Sean McAdam
Cheap, but impractical. You could not use it for regular processing.
But with enough Ram for buffer it could be real useful for some
specialized applications...
~Sean
--
----------------------------------------------|
| Sean McAdam |
| Systems Administrator / Software Engineer |
| FYI Online ( A tiny MCI/News Corp company ) |
| |
| The warp engines will work, but with the |
| inertial dampeners off-line we'll just |
| be stains on the back wall. - Lt. Paris |
| |
| @work se...@fyionline.com |
| @play se...@fredcom.com |
| http://www2.fyionline.com/~sean |
|----------------------------------------------
Michael Ashton
>I was wondering if anyone is working on a tape file system. It
>would be great to have an 8GB drive, well lots of them since those
>4mm 8GB tapes are cheap ($10 a piece, I think).
Do you mean to ask that which you ask ?
Nobody is working on a tape _file system_ because it is a fundamentally
stupid idea and will substantially damage your tape drive.
Tape support exists, except for floppy-based tape drives, support for which
is only half-there but usable.
--
mic...@unixsoft.demon.co.uk
"If I could see before the blindness, the smile you gave before the pain,
I could accept a world of darkness, and never see the sun again".
Rodney Fulk
>
>I was wondering if anyone is working on a tape file system. It
>would be great to have an 8GB drive, well lots of them since those
>4mm 8GB tapes are cheap ($10 a piece, I think).
>
Yea but do you really wanna prematurely wear out your tape drive?
Using your tape drive as a file system REALLY puts alot more wear and tear on
the drive. When you backup its streaming and doesnt wear as much but moving it back
and forth as in accessing a file system your asking for trouble.
Jared Mauch
Rodney Fulk <eli...@iserv.net> writes:
>che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
>>I was wondering if anyone is working on a tape file system. It
>>would be great to have an 8GB drive, well lots of them since those
>and forth as in accessing a file system your asking for trouble.
I wanna swap on it.
swapon /dev/rmt0
- Jared
John Taylor
: In article <48g47m$d...@everest.iserv.net>,
: swapon /dev/rmt0
: - Jared
No you don't. Go buy some more disk space and/or RAM.
This is about the worst possible way to swap.
--
John Taylor
tay...@pollux.cs.uga.edu
Do to others as you would have them do to you. Lk 6:31
Gary Foster
: In article <48g47m$d...@everest.iserv.net>,
: Rodney Fulk <eli...@iserv.net> writes:
: >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
: >>I was wondering if anyone is working on a tape file system. It
: >>would be great to have an 8GB drive, well lots of them since those
: >and forth as in accessing a file system your asking for trouble.
: I wanna swap on it.
: swapon /dev/rmt0
: - Jared
I really really really really really hope this is a troll... I really
really really really really hope you're kidding...
-- Gary F.
--
PGP public key available: finger gfo...@netcom.com
Alternate email address: gfo...@nummi.com
root
>Jared Mauch (ja...@nic.hq.cic.net) wrote:
>: In article <48g47m$d...@everest.iserv.net>,
>: Rodney Fulk <eli...@iserv.net> writes:
>: >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
>: >>I was wondering if anyone is working on a tape file system. It
>: >>would be great to have an 8GB drive, well lots of them since those
>: >and forth as in accessing a file system your asking for trouble.
>
>: I wanna swap on it.
>: swapon /dev/rmt0
>
>: - Jared
>I really really really really really hope this is a troll... I really
>really really really really hope you're kidding...
>-- Gary F.
run swapon on it. I only have a 4 meg machine, but I can compile the kernel
in an xterm using the tape as swap space. If anyone wants it, let me know.
df...@belvdere.vip.best.com
: I wrote a lame little tape fs that I was embarrassed to release, but you can
: run swapon on it. I only have a 4 meg machine, but I can compile the kernel
: in an xterm using the tape as swap space. If anyone wants it, let me know.
How long does it take to compile the kernel this way??
--
------------------------------------------------------------------------
David E. Fox Tax Thanks for lettimg me
df...@belvdere.vip.best.com the change magnetic patterns
ro...@belvedere.sbay.org churches on your hard disk.
-----------------------------------------------------------------------
Erik Corry
: : >>I was wondering if anyone is working on a tape file system. It
: : >>would be great to have an 8GB drive, well lots of them since those
:
: : swapon /dev/rmt0
:
: : - Jared
:
: No you don't. Go buy some more disk space and/or RAM.
: This is about the worst possible way to swap.
I think your humour detecters need a little tuning.
--
Erik Corry ehc...@inet.uni-c.dk
Peter T. Breuer
Amen! Just what kind of morons do we have out there? "John Taylor"
presumably can't claim language or culture difficulties for
his insensibility in the lower joke area. Perhaps its just a case of
having forgotten to run MAKEDEV on /dev/humor - personally, I thought
this thread showed great promise for the WOTY (wittiest of the year)
award.
I wait with bated breath for the posts correcting me on the use of
MAKEDEV.
: --
: Erik Corry ehc...@inet.uni-c.dk
--
Peter T. Breuer
,---------------------------------------------------------------------------
|Departamento de Ingenieria de Sistemas Telematicos, Universidad Politecnica
|de Madrid, Escuela Tecnica Superior de Ingenieros de Telecomunicacion,
|Ciudad Universitaria, E--28040 Madrid, SPAIN.
|Tel. Office : +34 (1)336 6831
| Fax : +34 (1)543 2077 or 336 7333
|Internet : <p...@eng.cam.ac.uk, p...@comlab.ox.ac.uk, p...@dit.upm.es>
| URL : http://www.dit.upm.es:80/~ptb/
|Other : GCS/E/M d H- s-: !g !p+ !au a w+ v+ C++ UL++++ UH+ UV+
| : P-- L+++ 3+ N+++ E--- K++ W+ M-- V-- po- Y t+ !5 !j R- G?
| : tv++ b- D+ !B e+++++ -u h+ !f r* n+ y?
`---------------------------------------------------------------------------
Chris Ruprecht
In <cheema.8...@nntp.msstate.edu> che...@Jupiter.SPARCO.Com (Mubashir Cheema) writes:
>I was wondering if anyone is working on a tape file system. It
>would be great to have an 8GB drive, well lots of them since those
>4mm 8GB tapes are cheap ($10 a piece, I think).
Do you mean to ask that which you ask ?
Nobody is working on a tape _file system_ because it is a fundamentally
stupid idea and will substantially damage your tape drive.
Tape support exists, except for floppy-based tape drives, support for which
is only half-there but usable.
It's not such a stupid idea. Many moons ago, back in 1987, I wrote
some book about an NCR Tower and NCR gave me one to play around
with. It did not have any floppy disk drives but only had a tape
drive. You could boot of the tape to install the OS on the hard disks
or boot of the tape to do emergency repairs. I don't advise running a
'life' file system with lots of traffice on a tape, but to install, it
would be great.
Getting a PC however, to boot of a tape drive is an entirely different
story ...
Regards,
Chris
--
----------------------------------------+-------------------------------------
Chris Ruprecht | E-Mail: ch...@rupeden.eurassi.co.za
Consultancy Services, Programming, | Phone (24h): +27 82 445-3804
Shareware, Freeware and PD Software | Snail Mail: P.O.Box 2485
PROGRESS, Linux, SCO, Windows | Edenvale 1610, South Africa
Strictly: Jeans, Sneakers, Non-Smoking | URL: http://www.eurassi.co.za/
----------------------------------------+-------------------------------------
Eduardo Casino-Almao
On 19 Nov 1995, Peter T. Breuer wrote:
> Erik Corry (er...@kroete2.freinet.de) wrote:
> : John Taylor (tay...@pollux.cs.uga.edu) wrote:
> : : Jared Mauch (ja...@nic.hq.cic.net) wrote:
> : : : >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
> : : : >>I was wondering if anyone is working on a tape file system. It
> : : : >>would be great to have an 8GB drive, well lots of them since thos=
e
> : : : =09I wanna swap on it.
> : :=20
> : : : =09swapon /dev/rmt0
> : :=20
> : : : =09- Jared
> : :=20
> : : No you don't. Go buy some more disk space and/or RAM.
> : : This is about the worst possible way to swap.
>=20
> : I think your humour detecters need a little tuning.
>=20
> Amen! Just what kind of morons do we have out there? "John Taylor"
> presumably can't claim language or culture difficulties for
> his insensibility in the lower joke area. Perhaps its just a case of
> having forgotten to run MAKEDEV on /dev/humor - personally, I thought
> this thread showed great promise for the WOTY (wittiest of the year)
> award.
That kind of "morons", Peter T. Breuer, are the guys who are willing to=20
help. If you are in this group to insult other people, you'd better take=20
all your sarcastic rubbish and leave us alone.
Let me use your own words and don't forget to run MAKEDEV on /dev/politenes=
s
-------->8 Cut here 8<---------
#!/usr/bin/ksh
cat flames > /dev/null 2>&1
-------->8----------8<---------
Greetings,
+--------------------------------------------------------------------------=
+
| Eduardo Casino Almao e-mail: edu...@medusa.es =
|
| C/ Agustin Duran, 5, 2=BAF e.ca...@spa1002.wins.icl.co.u=
k |
| 28028 MADRID =
|
| (Spain) Phone: +34 1 726 52 85 =
|
| =
|
| --- No, I do not have a web page --- =
|
| =
|
+--------------------------------------------------------------------------=
+
| "English well speaking. Here speeching American." =
|
| (From a Majorcan shop entrance) =
|
+--------------------------------------------------------------------------=
+
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Nathan Stewart
: root (ro...@chaos.anarch) wrote:
: : I wrote a lame little tape fs that I was embarrassed to release, but you can
: : run swapon on it. I only have a 4 meg machine, but I can compile the kernel
: : in an xterm using the tape as swap space. If anyone wants it, let me know.
: How long does it take to compile the kernel this way??
I'm sure he'll let us know whenever it finishes. ;-)
N8
Dave Otto
>Jared Mauch (ja...@nic.hq.cic.net) wrote:
>: In article <48g47m$d...@everest.iserv.net>,
>: Rodney Fulk <eli...@iserv.net> writes:
>: >>I was wondering if anyone is working on a tape file system. It
>: swapon /dev/rmt0
great, and the scanner can read it in. The only problem is the paper
handler getting the correct page to the scanner. Right now I am using one
of my kids, but I need to resolve this before marketing the product.
Dave Otto - Vinimus, Vedimus, Dolivamus
http://ACM.org/~daveotto/ http://ACM.org/~daveotto/linux.html/
da...@dvorak.jta.edd.ca.gov dave...@acm.org
"Pay no attention to the man behind the curtain!" [the Great Oz]
finger Dave...@ACM.org/or server for PGP 2.6 key <0x3300e841>
€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€€
Michael Meissner
| In article <48g47m$d...@everest.iserv.net>,
| Rodney Fulk <eli...@iserv.net> writes:
| >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
| >>I was wondering if anyone is working on a tape file system. It
| >>would be great to have an 8GB drive, well lots of them since those
|
| >and forth as in accessing a file system your asking for trouble.
|
| I wanna swap on it.
|
| swapon /dev/rmt0
DECtape lives :-)
--
Michael Meissner, Cygnus Support (East Coast)
Suite 105, 48 Grove Street, Somerville, MA 02144, USA
meis...@cygnus.com, 617-629-3016 (office), 617-629-3010 (fax)
Michael Meissner
| er...@kroete2.freinet.de (Erik Corry) wrote:
| >John Taylor (tay...@pollux.cs.uga.edu) wrote:
| >: Jared Mauch (ja...@nic.hq.cic.net) wrote:
| >: : >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
| >: : >>I was wondering if anyone is working on a tape file system. It
| >: : >>would be great to have an 8GB drive, well lots of them since those
| >: : I wanna swap on it.
| >:
| >: : swapon /dev/rmt0
| >:
| >: : - Jared
| >:
| >: No you don't. Go buy some more disk space and/or RAM.
| >: This is about the worst possible way to swap.
| >
| >I think your humour detecters need a little tuning.
|
| Never know...
| A friend of mine had an Adam computer and had a "swap" setup on it..
| The computer acted like it was locked up although that tape drive was whiring like
| a sun of a gun...
Sounds like a NCR53c810 with the standard driver.
Drew Eckhardt
Warwick Allison <war...@cs.uq.edu.au> wrote:
>Perhaps someone needs to explain what a tape filesystem is (when implemented
>in a useful way). I have heard of these things running on the Amiga.
>
>My understanding is that the directory inodes are stored at the start
>of the tape, and this is read to harddisk at mount; `block size' on the
>tape is VERY large, and extra effort is made to avoid file fragmentation.
Modern helical scan tapes are not block addressable, so you probably
want something log based instead of block oriented.
Lay down some subset of the changes to a file in a tape file with some
meta-data for crash-recovery, and keep a copy of all meta-data in the
last tape-file.
This would get you reasonable random access (modern tapes fastforward
between files relatively fast), and loose a minimal ammount of space when
things were re-written.
A hierchal filesystem would also be real interesting - back a $240
(I'm sure they're cheaper by now) 1.2G EIDE drive with a library of
data tapes at 2-4G a pop.
--
Everyone dies, but not everyone lives.
Jerry Natowitz
interpreted as a filesystem directory.
Also, if you read some of the more classic books on Computer Science, Knuth's
Seminumerical Algorithms comes to mind (volume 2 of the Art of Computer
Programming), tapes were commonly used as intermediate storage for large
sorting jobs. Having had to use scratch tapes as intermediate storage on
an IBM System 370, it isn't as bad as you'ld think. Of course, we are
talking multiple bidirectional drives ...
--
Jerry Natowitz - j...@spdcc.com
Warwick Allison
in a useful way). I have heard of these things running on the Amiga.
My understanding is that the directory inodes are stored at the start
of the tape, and this is read to harddisk at mount; `block size' on the
tape is VERY large, and extra effort is made to avoid file fragmentation.
Someone who knows more want to explain a little more about these
concepts?
In theory, a tape filesystem should be able to be used as a
familiar backup interface:
cp /usr /tape
# Takes as long as tar c /usr
ls /tape/usr/local/src
# This comes quickly from the disk cache of the directory inodes.
... foo ...
cp -r /tape/usr/local/src/foo .
# This causes a tape seek and transfer.
umount /tape
# Directory inodes, if any are changed, are rewritten to tape.
mount /tape
# Directory inodes are read from tape to disk.
...
The tape filesystem has certain requirements from the tape mech, of course,
as does mt, etc.
--
Warwick
--
_-_|\ war...@cs.uq.oz.au Linux: Life After DOS.
/ * <- Comp Sci Department, McD: http://student.uq.edu.au/~s002434/mcl.html
\_.-._/ Univ. of Queensland, POV: http://student.uq.edu.au/~s002434/pov.html
v Brisbane, Australia. ME: http://student.uq.edu.au/~s002434
Christian Tan
>I've been working on a driver to swap to the printer. The "writing" works
>great, and the scanner can read it in. The only problem is the paper
>handler getting the correct page to the scanner. Right now I am using one
>of my kids, but I need to resolve this before marketing the product.
Heh. I once read something abouth swapping with NFS/TCP/IP on
internet...
--
------------------------------------------------------------------------------
Christian Tan, E-mail:pig...@xs4all.nl, WWW: http://www.xs4all.nl/~pigeon
Gary Foster
: In article <48q7ui$2...@hopper.acm.org>, Dave Otto wrote:
: >I've been working on a driver to swap to the printer. The "writing" works
: >great, and the scanner can read it in. The only problem is the paper
: >handler getting the correct page to the scanner. Right now I am using one
: >of my kids, but I need to resolve this before marketing the product.
: I don't suppose any of you have used a WORM drive for swap space, either.
No, but after all this traffic I guess I should dust off my email swap
system... using UUENCODE | mail to swap out pages of ram to spool space
on the internet, and then asking for it back when I need the particular
page. It ran kinda slow, yeah, but I had HUGE amounts of swap space
available...
swapon big_...@foobar.com
Michael Ashton
>Also, if you read some of the more classic books on Computer Science, Knuth's
>Seminumerical Algorithms comes to mind (volume 2 of the Art of Computer
>Programming), tapes were commonly used as intermediate storage for large
>sorting jobs.
So were punched cards.
--
mic...@unixsoft.demon.co.uk
``So it seems that women cause more fights than pool tables''
Anon.
Michael Ashton
>That kind of "morons", Peter T. Breuer, are the guys who are willing to=20
>help.
but not willing to configure their software=20properly.
>If you are in this group to insult other people, you'd better take=20
>all your sarcastic rubbish and leave us alone.
>#!/usr/bin/ksh
>cat flames > /dev/null 2>&1
Very efficient...
#!/bin/sh
rm -f flames
seems somewhat better.
Michael Ashton
>Heh. I once read something abouth swapping with NFS/TCP/IP on
>internet...
Diskless workstations are frequently configured to swap across NFS. What's
so funny about that ?
Michael Ashton
>In article <gfosterD...@netcom.com>, gfo...@netcom.com (Gary Foster) writes:
>>Jared Mauch (ja...@nic.hq.cic.net) wrote:
>>: In article <48g47m$d...@everest.iserv.net>,
>>: Rodney Fulk <eli...@iserv.net> writes:
>>: >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
>>: >>I was wondering if anyone is working on a tape file system. It
>>: I wanna swap on it.
>>: swapon /dev/rmt0
>I've been working on a driver to swap to the printer.
Actually, this could be useful of powerful postscript printers and quite easy
to do.
>The "writing" works great, and the scanner can read it in. The only problem
>is the paper handler getting the correct page to the scanner. Right now I
>am using one of my kids, but I need to resolve this before marketing the
>product.
Are you scanning digitally or using OCR ?
Larry Daffner
>A hierchal filesystem would also be real interesting - back a $240
>(I'm sure they're cheaper by now) 1.2G EIDE drive with a library of
>data tapes at 2-4G a pop.
>--
>Everyone dies, but not everyone lives.
Besides being intersting, this would be a real challenge. I know of
whence I speak, since this is what I do from day to day. And for any
of you that think that an OS is complex... :)
Not speaking for his employer..
-Larry
--
Larry Daffner - Software Engineer | email: ldaf...@convex.com |
Convex Computer Corporation | tel: (214)497-4274 / home: (214)380-4382 |
It's better to be silent and be thought a fool than to speak and remove all
doubt. --Abraham Lincoln
Guangliang He
Christian Tan <pig...@xs4all.nl> wrote:
>
>Heh. I once read something abouth swapping with NFS/TCP/IP on
>internet...
>
>------------------------------------------------------------------------------
>Christian Tan, E-mail:pig...@xs4all.nl, WWW: http://www.xs4all.nl/~pigeon
Seriously, is it how swap is done on those diskless workstations?
Guangliang He
g...@physics.orst.edu
Frank van de Pol
> Mubashir Cheema wrote:
> >
> > I was wondering if anyone is working on a tape file system. It
> >
> Cheap, but impractical. You could not use it for regular processing.
> But with enough Ram for buffer it could be real useful for some
> specialized applications...
Not special for Sean, but also for all those others that have no clue what a
tape fs is:
I disagree! A tape fs is *very* usefull. ok, you can't (practically) use it
like a disk, but for archiving files, it's very good. VMS (yes, the
operation system running on DEC VAX and alpha processors) offers such a tape
fs.
A tape fs is much the same as a worm, or CD writable device: you can add
files to it, but not delete them, as this would mean relocating lots of
blocks, or creating fragmented files. A deleted file would be just *marked*
as deleted, or marked as 'older version'. Setting up the index/directory
table is *the* trick for tape file systems. If one can only add files to a
fresh (initialised) tape, a directory structure is also not needed. By
storing not only the file name, but also the directory name (relative to
mount point :-), the fs can 'fake' the directory structure.
With a tape fs, one can really fill up his or hers 8GB DAT tape. Suitable
for archiving data. (Adding files to it every day or so!)
Think about it, and you'll agree that a tape fs is not *that* weird.
Regards,
Frank.
--
========================---------------->
#define NAME "Frank van de Pol"
#define ADDRESS "mgr. Nelislaan 10"
#define CITY "4741 AB Hoeven"
#define COUNTRY "The Netherlands"
#define EMAIL "F.K.W.va...@inter.NL.net
The gates in my computer are AND,OR and NOT, not Bill
Pavel Korensky
> Perhaps someone needs to explain what a tape filesystem is (when implemented
> in a useful way). I have heard of these things running on the Amiga.
>
> My understanding is that the directory inodes are stored at the start
> of the tape, and this is read to harddisk at mount; `block size' on the
> tape is VERY large, and extra effort is made to avoid file fragmentation.
>
> Someone who knows more want to explain a little more about these
> concepts?
>
> In theory, a tape filesystem should be able to be used as a
> familiar backup interface:
>
> cp /usr /tape
> # Takes as long as tar c /usr
>
> ls /tape/usr/local/src
> # This comes quickly from the disk cache of the directory inodes.
> ... foo ...
>
> cp -r /tape/usr/local/src/foo .
> # This causes a tape seek and transfer.
>
> umount /tape
> # Directory inodes, if any are changed, are rewritten to tape.
>
> mount /tape
> # Directory inodes are read from tape to disk.
>
> ...
>
> The tape filesystem has certain requirements from the tape mech, of course,
> as does mt, etc.
>
Yes, several times I thought about the tape filesystem. I have the
program Tapedisk for DOS. It is a device driver which can make the dos
drive (L: on my computer). Tape is mounted and the whole system is
looking like 2GB disk. Erasing is possible, but files are not erased,
only marked out. So after each erase, the capacity of the "disk" is going
down. But the whole thing is working like a charm. Stable, very fast for
sequencial reading etc. I am using this software for 3D Studio (I am
putting the result images on the DAT).
It will be nice to have such software for Linux.
Best regards
PavelK
****************************************************************************
* Pavel Korensky (pav...@dator3.anet.cz) *
* DATOR3 Ltd., Modranska 1895/17, 143 00 Prague 4, Czech Republic *
* PGP key fingerprint: 00 65 5A B3 70 20 F1 54 D3 B3 E4 3E F8 A3 5E 7C *
****************************************************************************
Alex Martelli
...
>: >I was wondering if anyone is working on a tape file system. It
<shudder>
>: Nobody is working on a tape _file system_ because it is a fundamentally
>: stupid idea and will substantially damage your tape drive.
>I think a tape file system would be great for storage.
>It would be much better than using tar and all..
>One could create directories and would not worry about
>tape volumes and all that crap..
>I am all for an ftape fs. Please let me know if anything is available.
I'm pretty sure we pensioned off the last of the old "filesystem on tape"
devices from HP a couple years ago -- believe me, unless you've *seen*
that monstruous jerking motion, and *heard* it go chug-chug-chug at
(when you were lucky) one quarter the "speed" that the same generation
technology could easily achieve on *streaming* tape drives, you've
missed a LOT... if you're an Addams Family fan, I mean (hey, _I_ am!).
So, I can understand the morbid attraction of the idea of making a
filesystem (or any other block-oriented, as opposed to streaming, usage
pattern) on a tape... but, remember -- the HP horror in question at least
ran on top-quality mechanics carefully engineered by brilliant techies
to be able to TAKE the sudden, repeated, continuous stop/go stresses --
they couldn't make it FAST, of course, but at least they could prevent
self-destruction of the mechanisms! Doing the same thing *in software*,
on hardware NOT designed for such abuse but rather definitely designed
for streaming operation, goes beyond benign "Addams Family" horror and
rapidly veers towards the splatter, or "120 days of Sodom", varieties.
If this IS your tastes -- hey, go ahead, have fun!-)
Alex
--
Alex Martelli, Bologna, Italia -- DISCLAIMER: these are only MY opinions...!
__ Man has no Body distinct from his Soul... | William Blake
\/ Energy is the only life, and is from the Body... | DID know
Energy is Eternal Delight. | where it's at...
A Shelton
>In article <gfosterD...@netcom.com>, Gary Foster wrote:
>>Jared Mauch (ja...@nic.hq.cic.net) wrote:
>>: In article <48g47m$d...@everest.iserv.net>,
>>: Rodney Fulk <eli...@iserv.net> writes:
>>: >che...@Jupiter.SPARCO.Com (Mubashir Cheema) wrote:
>>: >>I was wondering if anyone is working on a tape file system. It
>>: >>would be great to have an 8GB drive, well lots of them since those
>>: >and forth as in accessing a file system your asking for trouble.
>>
>>: I wanna swap on it.
>>: swapon /dev/rmt0
>>
>>: - Jared
>>I really really really really really hope this is a troll... I really
>>really really really really hope you're kidding...
>>-- Gary F.
>I wrote a lame little tape fs that I was embarrassed to release, but you can
>run swapon on it. I only have a 4 meg machine, but I can compile the kernel
>in an xterm using the tape as swap space. If anyone wants it, let me know.
< A reply bounced >
I seem to remember that Linus said something like that about the 0.01 sources
he released :)
I look forward to seeing it on Sunsite, means if someone wants to experiment
with such idea's they get a real kickstart.
(heck, I've got a QIC, I like the Idea of dumping TAR...)
--
Linux, because raw power can be....addictive.
Andrew Shelton s940...@yallara.cs.rmit.edu.au
GCS(2.1)-d+H+sw+v-C++UL+>L+++E-N++WV--R++tv-b+D++e+fr*y?
Philip Blundell
Frank van de Pol <F.K.W.va...@inter.NL.net> wrote:
>I disagree! A tape fs is *very* usefull. ok, you can't (practically) use it
>like a disk, but for archiving files, it's very good. VMS (yes, the
>operation system running on DEC VAX and alpha processors) offers such a tape
>fs.
>
>A tape fs is much the same as a worm, or CD writable device: you can add
>files to it, but not delete them, as this would mean relocating lots of
>blocks, or creating fragmented files. A deleted file would be just *marked*
Indeed. Even a read-only tape FS would be useful. I would quite like to be
able to dump an entire filesystem to tape, then mount it as normal and read
files off.
Yes, it would be slow, but I wouldn't expect to use it every day and (IMHO)
it would be far more convenient than tar for looking at archived files. It
also has the advantage that permissions and ownership would be preserved, so
I could let other people restore their own files from tape with relative
impunity.
Phil
--
philip blundell trinity college cambridge 01223 356256 pj...@cam.ac.uk
David Thomas Richard Given
Eduardo Casino-Almao <edu...@medusa.es> wrote:
>-----BEGIN PGP SIGNED MESSAGE-----
>
(27 lines of quoted article cut)
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You mentioned not alienating `people who want to help'... considering the
signal-to-noise ratio of your message, your style of help contributes a
lot to bandwidth and not a lot to information. This is undesirable.
--
-------------------------------------------------------------------------------
Why do people surf the Information Superhighway? Won't they get run over?
http://www-hons-cs.cs.st-andrews.ac.uk/~dg
Sun-Earther David Daton Given of Lochcarron
David Thomas Richard Given
Guangliang He <g...@mars.superlink.net> wrote:
>In article <5mXswMsC...@xs4all.nl>,
>Christian Tan <pig...@xs4all.nl> wrote:
>>Heh. I once read something abouth swapping with NFS/TCP/IP on
>>internet...
>
Yup. That's how our network of Sun dickless workstations swap. I happened
to be in the vicinity of someone who was doing a major compile (and had
been for some time) when he found out... his response was, er, loud.
root
This is actually a very good idea, as it allows you to save large file
(images, etc) to cheap removable media.
The logistics of making such a fs are easily worked out, and I beleive
that someone has already released software for DOS that does this.
Taufiq Habib
ha...@delphi.com
Larry Daffner
>A tape fs is much the same as a worm, or CD writable device: you can add
>files to it, but not delete them, as this would mean relocating lots of
>blocks, or creating fragmented files. A deleted file would be just *marked*
>as deleted, or marked as 'older version'. Setting up the index/directory
>table is *the* trick for tape file systems. If one can only add files to a
>fresh (initialised) tape, a directory structure is also not needed. By
>storing not only the file name, but also the directory name (relative to
>mount point :-), the fs can 'fake' the directory structure.
>With a tape fs, one can really fill up his or hers 8GB DAT tape. Suitable
>for archiving data. (Adding files to it every day or so!)
Why do you need a tape filesystem for this? Tar will already do this
for you. (check out the -r and -u operations) F'r instance: I have a
directory tree, say src, and I create a tar archive on my 8GB DAT.
Then, a week later, I've made changes, and want to stay current. So,
I just do a tar -u to the tape, and it updates any files I've changed,
and leaves any files that haven't changed there. This has 2
advantages over the tape filesystem you proposed:
1) It's portable. You can pop that tape into just about any
computer's DAT drive, do a tar -x and get your files.
2) tar will manage the files for you. You don't have to worry about
figuring out what files have been changed and writing them.
If there's other, more specialized needs for a tape fs, then maybe
there's a need for one. But don't write a FS replacement for TAR. The
kernel is already starting to get somewhat overwhelming at times.
-Larry
--
Larry Daffner - Software Engineer | email: ldaf...@convex.com |
Convex Computer Corporation | tel: (214)497-4274 / home: (214)380-4382 |
Hare's Law:
Inside every large program is a small program struggling to get out.
Joe Mack
>Followup to: <4931gp$s...@goanna.cs.rmit.EDU.AU>
>By author: s940...@yallara.cs.rmit.EDU.AU (A Shelton)
>In newsgroup: comp.os.linux.development.system
>>
>> >I wrote a lame little tape fs that I was embarrassed to release, but you can
>> >run swapon on it. I only have a 4 meg machine, but I can compile the kernel
>> >in an xterm using the tape as swap space. If anyone wants it, let me know.
>>
I wouldn't mind looking at it, but I can't figure out who the original poster
is. Can you contact me?
Thanks Joe Mack
ma...@ncifcrf.gov
Greg Nelson
I've been pondering for a while.
I'd like to see an "intersrv" compatible filesystem. For those who
are not familiar with the thing, DOS 6.2 (maybe earlier) includes
drivers that allows you to connect two machines together (via a
serial or parallel cable) and effectively mount remote hard drives
(and floppies and printers) as if they were slow local devices. Using
the parallel port, the performance is even "not unreasonable", at
about 600kB/sec.
While it would be easy enough to hack together a similar protocol for
Linux (create a new /dev file with the right drivers behind it, mount
it as a msdos or umsdos partition), what would be really amazing is if
the protocol were compatible with the DOS software. Then you could
use this capability equally well between two linux machines, or
between a linux machine and a DOS machine. Unfortunately, I don't
know where to find out information about the protocol. It's possible
it's in a book somewhere... if anyone knows about it, let me know and
I'll start hacking.
Otherwise, I'll have to wait until I get three machines to play with
-- I've figured out the cable wiring, and I think all I need to do is
set up a linux machine running a logging "packet snooper" on the
parallel cable while two other machines run the protocol.
So, if anyone has already done this, or has suggestions or
information, or wants to know more about things like the cable wiring
for their own purposes, let me know.
Greg Nelson
g...@cs.cmu.edu
Matt Welland
>In article <19571@817158898>,
>Frank van de Pol <F.K.W.va...@inter.NL.net> wrote:
>>I disagree! A tape fs is *very* usefull. ok, you can't (practically) use it
>>like a disk, but for archiving files, it's very good. VMS (yes, the
[good stuff deleted...]
I think this has been hashed out before, but what I would like to see is an
archive file system using tape. Certain criteria are set such as file "age"
and "safety" and required free space. A cron job runs every night which
scans the file system looking for old, non-critical files and compresses and
archives them on tape. A dummy file of zero length is left on the disk
(maybe a named pipe?). If a read, execute or write is performed on the file
the appropriate action is taken, i.e., the file is pulled from the archive
etc. I have hundreds of files on my system that are either never or seldom
used. It is a waste of my time to figure out which ones are critical and
which ones can be deleted. How about extending "double" to handle this? For
this application the filesystem on tape would make sense. If you set
reasonable critera access to the files on tape would be minimal. I set
"Infinite Disk" up for a friend on a Windows PC and it worked great. A good
model perhaps for this kind of thing.
--
,------------------------------------------------------------.
| Matt Welland | Medtronic/Micro-Rel |
| Design Engineer | IC CAE group |
`----------...@tmp.medtronic.com---------------------'
Charles Todd
> The discussion of a tape filesystem for Linux brings to mind an idea
> I've been pondering for a while.
> I'd like to see an "intersrv" compatible filesystem. For those who
> are not familiar with the thing, DOS 6.2 (maybe earlier) includes
> drivers that allows you to connect two machines together (via a
> serial or parallel cable) and effectively mount remote hard drives
> (and floppies and printers) as if they were slow local devices. Using
> the parallel port, the performance is even "not unreasonable", at
> about 600kB/sec.
Check out the documentation for PLIP (Parallel IP) and then you
could set up your drives as NFS.
> While it would be easy enough to hack together a similar protocol for
> Linux (create a new /dev file with the right drivers behind it, mount
> it as a msdos or umsdos partition), what would be really amazing is if
> the protocol were compatible with the DOS software. Then you could
> use this capability equally well between two linux machines, or
> between a linux machine and a DOS machine. Unfortunately, I don't
> know where to find out information about the protocol. It's possible
> it's in a book somewhere... if anyone knows about it, let me know and
> I'll start hacking.
A small program came with XTreeGold for DOS that let you "network"
the drives. I guess we could follow suit and connect the two machines
via dosemu and maybe dosemu would let unix have access...who knows.
I know one fella had a device that worked on the parallel port so
what he did was started up DOSEMU in Linux and had another program
port snooping the parallel port. Once he figured out the protocol
(not easy, he said) he was able to put an Alpha version of his package
out. Unfortunately, I don't know who they guy was or what package
he was talking about. I'll see if the article is still in
comp.os.linux.announce....
Charlie Todd
s00...@discover.wright.edu
--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
JFK's Last Words: I have half a mind to quit this job.
--------
Q: What's the difference between a rooster and a lawyer?
A: A rooster clucks defiance.
--------
The very powerful and the very stupid have one thing in common.
Instead of altering their views to fit the facts, they alter the facts
to fit their views ... which can be very uncomfortable if you happen to
be one of the facts that needs altering.
-- Doctor Who, "Face of Evil"
Paul Slootman
>> >run swapon on it. I only have a 4 meg machine, but I can compile the kernel
>> >in an xterm using the tape as swap space. If anyone wants it, let me know.
>
>things better done in user space, and caching files to disk so you
>won't grind your tapes to little pieces is probably one of those. :-)
I may be missing something here, but somehow I think there are a couple
of problems here:
- "Caching files to disk" may generally be a good idea, but not if
the purpose of writing the stuff to disk is swapping (which the
purpose of the tape thing was in the first couple of messages). The
cache will use RAM, and you have to swap because you don't have
enough RAM...
- Handling swapping in user space somehow seems a no-no... Think
about it: the kernel has to swap because some user program needs
the memory to run; what if the user program in question is the
userfs process?
I think some people need to get a grip on reality from time to time
to prevent them from tripping over themselves in their enthusiasm :-)
Something that *could* be useful, is a tape drive that has a
significant buffer... the amount of data that is written to and
from the drive should be limited to fall within that buffer, so
that all I/O can be satisfied by the buffer, without the physical
tape itself actually becoming involved!
[ Now, where did I leave the valium and the reality... :-) ]
Paul Slootman
--
key to UNIX: echo '16i[q]sa[ln0=aln100%Pln100/snlbx]sbA0D4D465452snlbx'|dc
Murphy Software, Enschede, The Netherlands
work: pa...@ahwau.ahold.nl / pa...@murphy.nl
home: pa...@wurtel.hobby.nl
Tommy Thorn
| - Handling swapping in user space somehow seems a no-no... Think
| about it: the kernel has to swap because some user program needs
| the memory to run; what if the user program in question is the
| userfs process?
|
| I think some people need to get a grip on reality from time to time
| to prevent them from tripping over themselves in their enthusiasm :-)
Yeah, get a grip. User level swap handing is certainly possible and a
big point of several Mach papers. For some applications, it can buy
you _a lot_ to be able to use applications specific knowledge to guide
swapping. Even in Linux, user level swap handling is theoretically
feasible, as you can lock the pages of the swap handler in memory with
mlock (recent kernels).
As for the original issue of this thread, a type file system and
swapping to tape, it escapes me how people can find it useful. One
thing that _could_ be useful is a hierarchical file system, with fast
storage in top (eg. ram and disk) and slow at the bottom (optical disc
and tape), which would automatically move files between layers based
on usage patterns. This, however, is not something for small systems.
David Thomas Richard Given
For those of you with *really* sick minds, insert a blank floppy and type:
mkswap /dev/fd0
swapon /dev/fd0
It really works. Scary.
David Thomas Richard Given
Albert Cahalan <alb...@krakatoa.ccs.neu.edu> wrote:
>M> Its silly to swap on a tape! You have to swap on the fastest
>M> that you have! I have a 5 Mb ramdisk to swap, its really fast!
>
>I hope you are one of those very few people who have hacked the
>kernel to use an expanded memory board or uncachable RAM.
>If not, this is a serious waste of RAM that could be used directly
>instead of as swap.
Silly that may sound, but if you have more than 32 MB of memory and run
Windows (poor, deluded fool), then MS recommend using the rest of the
memory as a ramdisk and swapping to it.
Somebody, please, prove me wrong.
Alan Barclay
--
Alan Barclay
The Electric Scribe Co. Ltd.
al...@escribe.co.uk
Don Broderick [N3GUZ]
someone in this thread posted (shyly) a note about their work on a
tapeFS... although I've scoured my news spool, I can't make out who it
was, or how to get the code.
Could someone repost this information, or the code itself?
--
Don Broderick Voice: (412)237-3152
Unix Systems Programmer Fax: (412)237-3091
Community College of Allegheny County Pager: (412)649-9926
800 Allegheny Ave. <brod...@demo.ccac.edu>
Pittsburgh, PA 15233
David A Willmore
>>Jared Mauch (ja...@nic.hq.cic.net) wrote:
>>: I wanna swap on it.
>>
>>: swapon /dev/rmt0
>For those of you with *really* sick minds, insert a blank floppy and type:
>mkswap /dev/fd0
>swapon /dev/fd0
>It really works. Scary.
Hey, don't laugh too loudly. I used to have to do that on a 2meg machine
to be able to compile the kernel. 386/20 w/ 2 meg 40 meg HD with only enough
partitioned space for the actual source code. At 5:00, reboot into Linux,
put in a floppy, swapon it, start a build and come back after the weekend...
Of course, we've come a long way since Linux v.12
Cheers,
David
Michael Elizabeth Chastain
Ok, I agree with this.
> I have a 5 Mb ramdisk to swap, its really fast!
Either I am missing a clue, or you are!
Why don't you simply let the OS use the ram and keep applications in it
so it doesn't have to swap at all?
Michael Chastain
m...@duracef.shout.net
A Shelton
>In article <497gqk$m...@lyra.csx.cam.ac.uk> pj...@thor.cam.ac.uk (Philip Blundell) writes:
>>In article <19571@817158898>,
>>Frank van de Pol <F.K.W.va...@inter.NL.net> wrote:
>>>I disagree! A tape fs is *very* usefull. ok, you can't (practically) use it
>>>like a disk, but for archiving files, it's very good. VMS (yes, the
>>philip blundell trinity college cambridge 01223 356256 pj...@cam.ac.uk
>[good stuff deleted...]
>I think this has been hashed out before, but what I would like to see is an
>archive file system using tape. Certain criteria are set such as file "age"
>and "safety" and required free space. A cron job runs every night which
>scans the file system looking for old, non-critical files and compresses and
>archives them on tape. A dummy file of zero length is left on the disk
>(maybe a named pipe?). If a read, execute or write is performed on the file
>the appropriate action is taken, i.e., the file is pulled from the archive
>etc. I have hundreds of files on my system that are either never or seldom
>used. It is a waste of my time to figure out which ones are critical and
>which ones can be deleted. How about extending "double" to handle this? For
>this application the filesystem on tape would make sense. If you set
>reasonable critera access to the files on tape would be minimal. I set
>"Infinite Disk" up for a friend on a Windows PC and it worked great. A good
>model perhaps for this kind of thing.
That'd be cool, but I'm not sure I'd trust Tape/automation to that extent.
Especially when HD is relatively cheap.
What I'd like would be a fake directory structure, say /tape, that I can
copy and delete 'images' from and then, either from cron or manually sync
the whole lot to an archived tape.
The Idea of copying things out and then uttering an 'execute' instruction
seems a lot easier than using tar to backup and the pain of creating
an archive you are never totally sure you'll be able to recover. It could
even go and check, at intervals, that the save tape is still good (since it
knows where the original files are) and whether they've been updated.
The tape gets to act as a streaming medium and when you need to recover
from a total disaster you just mount the tape (I-nodes get read) and can
browse a tree full of guaranteed up to data data using standard unix
commands.
Is that doable/sensible?.... whats the wizard level required?
Tommy Thorn
| >mkswap /dev/fd0
| >swapon /dev/fd0
|
| >It really works. Scary.
|
| Hey, don't laugh too loudly. I used to have to do that on a 2meg machine
| to be able to compile the kernel. 386/20 w/ 2 meg 40 meg HD with only enough
| partitioned space for the actual source code. At 5:00, reboot into Linux,
| put in a floppy, swapon it, start a build and come back after the weekend...
| Of course, we've come a long way since Linux v.12
I doubt you can do that anymore. The source takes about 16meg and
adding the objects files leave little room for anything else. Since
1.3.15 I've given up compiling on a 386sx/16 4meg 60meg HD (notebook).
Simply not enough space. It makes me sad though. I used to try
almost every version, but in the end I could hardly compile fast
enough to follow Linus's speed :-)
/Tommy
Frank Ranner
> Silly that may sound, but if you have more than 32 MB of memory and run
> Windows (poor, deluded fool), then MS recommend using the rest of the
> memory as a ramdisk and swapping to it.
>
> Somebody, please, prove me wrong.
>
You are probably correct. The reason is that Windows will run out of
'free resources' long before it runs out of main memory. Someone once
said 'Only Microsoft would replace the 640K barrier with a 64K barrier' a
reference to the fact that critical memory heaps in the GDI and USER
modules are 64K segments.
Us Linux users have got it easy: If the disk goes off its brain and the
machine slows to a crawl, add another 4 or 8 megs!
Frank Ranner
BThompson1
Subject: Re: Anyone working on a tape file system ?
From: pj...@thor.cam.ac.uk (Philip Blundell)
Date: 25 Nov 1995 16:38:44 GMT
Message-ID: <497gqk$m...@lyra.csx.cam.ac.uk>
In article <19571@817158898>,
Frank van de Pol <F.K.W.va...@inter.NL.net> wrote:
>I disagree! A tape fs is *very* usefull. ok, you can't (practically) use
it
>like a disk, but for archiving files, it's very good. VMS (yes, the
>operation system running on DEC VAX and alpha processors) offers such a
tape
>fs.
>
>A tape fs is much the same as a worm, or CD writable device: you can add
>files to it, but not delete them, as this would mean relocating lots of
>blocks, or creating fragmented files. A deleted file would be just
*marked*
Indeed. Even a read-only tape FS would be useful. I would quite like to
be
able to dump an entire filesystem to tape, then mount it as normal and
read
files off.
Yes, it would be slow, but I wouldn't expect to use it every day and
(IMHO)
it would be far more convenient than tar for looking at archived files.
It
also has the advantage that permissions and ownership would be preserved,
so
I could let other people restore their own files from tape with relative
impunity.
----- End Original Message -----
If we ignore the concerns about wear-and-tear to the tape drive mechanism,
and we ignore concerns about wear-and-tear to the tape itself, and if we
further ignore concerns about speed of access then I think I have a
suggestion that could make everyone happy.
Enter the TARFS, or perhaps even better the AFIOFS. Using the userfs
kernel module surely someone could write a file system that reads a tape
archive to find files. The filesystem would be read-only, and the
directory stsructure could be read of at mount time to determine inode
numbers and the like.
Cheers,
Bruce.
--
Bruce Thompson
Newton Systems Group, Developer Technical Support Group
BThompson1 (eWorld)
BThompson (AppleLink)
br...@newton.apple.com
David A Willmore
Well, the .12 source was much smaller. ;) Not all that much was in it. I
think I still have a copy. I should try it to see if it still works...
Cheers,
David
Hamish Macdonald
>>>>> In message <DIG6M...@unixsoft.demon.co.uk>,
>>>>> Michael Ashton <mas...@unixsoft.demon.co.uk> wrote:
Michael> Diskless workstations are frequently configured to swap
Michael> across NFS. What's so funny about that ?
Ouch. It wasn't funny when I was exposed to it. In 1988 I used a
network of diskless Sun3/50s with 4 megabytes of memory. These
machines were "disked" by a single "bigger" Sun3 via NFS.
At the time we were using X10, I think. Every hour, some sort of
maintenance function was started on all of them at once. They'd all
immediately swap over the single ethernet segment to the NFS server.
Basically everybody in the lab would just watch lines on xload build
and build and build. You couldn't do anything for at least 10
minutes.
Eventually we persuaded the administrators to stagger the maintenance
actions by a few minutes for each machine.
St. Opperskalski
www.worms.fh-rpl.de/~oppersk/
It's ALPHA :)
--
Stefan Opperskalski
--> opp...@nibelung.Worms.Fh-Rpl.DE