DVD-RAM
-bill-
with DVD-RAM drives.
What is the uncompressed capacity of single sided DVD-RAM drives
What is the uncompressed capacity of double sided DVE-RAM drives, and
are they available ?
Anthony Lawrence
> we are looking at replacing aging (and not quite adequate) DDS-2 drives
> with DVD-RAM drives.
>
> What is the uncompressed capacity of single sided DVD-RAM drives
4.7 GB. See http://aplawrence.com/Reviews/dvdram.html
> What is the uncompressed capacity of double sided DVE-RAM drives, and
> are they available ?
>
Apparently outside of the U.S., but google turns up nothing in any
language I can read.
--
Tony Lawrence
Free Linux Skills Test: http://aplawrence.com/skillstest.html
Bill Vermillion
-bill- <nob...@SpamCop.net> wrote:
>we are looking at replacing aging (and not quite adequate) DDS-2
>wdrives ith DVD-RAM drives.
You did not say what was not quite adequqted about the DDS-2.
>What is the uncompressed capacity of single sided DVD-RAM drives
>What is the uncompressed capacity of double sided DVE-RAM drives, and
>are they available ?
Even with doubled side DVD's I've not seen any changers in my
wanderings - perhaps someone else can comment on that.
If you upgrade to DDS-3 or DDS-4 it will be just drop-in
replacement with the ability to read your old tapes and only having
to configure your backup programs to be aware of the larger size.
If it's a size limitation when you say inadequate the DVD-RAMs
aren't going to give you much of an advantage over DDS-2.
If it's price the VXA at $699 handle 33GB uncompressed on 8MM
media.
From there prices go up and capacity goes up, and capacity keeps
going up and up. Sony just announced their 500GB native mode
Super-AIT drives in the last couple of weeks, which will give 1TB with
HW compression. No idea on prices but it will be up there in the
higher price range as their AIT-3's are in the mid $3K.
That's serious storage.
The LTOs aren't expected to match that capacity for about 6 months.
We all benefit by the competition between those formats.
Bill
--
Bill Vermillion - bv @ wjv . com
Anthony Lawrence
> In article <3e05e9aa$0$1396$2c3e...@news.voyager.net>,
> -bill- <nob...@SpamCop.net> wrote:
>
>
>>we are looking at replacing aging (and not quite adequate) DDS-2
>>wdrives ith DVD-RAM drives.
>
>
> You did not say what was not quite adequqted about the DDS-2.
>
>
>>What is the uncompressed capacity of single sided DVD-RAM drives
>>What is the uncompressed capacity of double sided DVE-RAM drives, and
>>are they available ?
>
>
> Even with doubled side DVD's I've not seen any changers in my
> wanderings - perhaps someone else can comment on that.
>
> If you upgrade to DDS-3 or DDS-4 it will be just drop-in
> replacement with the ability to read your old tapes and only having
> to configure your backup programs to be aware of the larger size.
>
> If it's a size limitation when you say inadequate the DVD-RAMs
> aren't going to give you much of an advantage over DDS-2.
>
> If it's price the VXA at $699 handle 33GB uncompressed on 8MM
> media.
The advantage of dvd-ram is price and longevity. IDE DVD-RAMS are
getting very inexpensive and even the top of the line (with capability
to write CD's in addition to DVD-R* ) are under $400.00. Low end units
are under $200.00. DVD-RAM media can be over-written for years and
years - they say 100,000 writes and a 30 year media life. That's
"forever" for most of us.
At the present time, if you have more data than you can compress to 4.7
GB (in the field I see that as typically around 9 GB), tape is obviously
the way to go. Another reason you might need tape is speed: DVD-RAM
isn't blindingly fast on writing - say about 3GB an hour for the units
I've used. Otherwise, I wouldn't use tape - this is cheaper, and far
more reliable.
-bill-
> Bill Vermillion wrote:
>
>> In article <3e05e9aa$0$1396$2c3e...@news.voyager.net>,
>> -bill- <nob...@SpamCop.net> wrote:
>>
>>
>>> we are looking at replacing aging (and not quite adequate) DDS-2
>>> wdrives ith DVD-RAM drives.
>>
>>
>>
>> You did not say what was not quite adequqted about the DDS-2.
>>
Capacity.
>>
>>> What is the uncompressed capacity of single sided DVD-RAM drives
>>> What is the uncompressed capacity of double sided DVE-RAM drives, and
>>> are they available ?
>>
>>
>>
>> Even with doubled side DVD's I've not seen any changers in my
>> wanderings - perhaps someone else can comment on that.
>>
>> If you upgrade to DDS-3 or DDS-4 it will be just drop-in
>> replacement with the ability to read your old tapes and only having
>> to configure your backup programs to be aware of the larger size.
>>
>> If it's a size limitation when you say inadequate the DVD-RAMs
>> aren't going to give you much of an advantage over DDS-2.
>>
>> If it's price the VXA at $699 handle 33GB uncompressed on 8MM
>> media.
>
>
> The advantage of dvd-ram is price and longevity. IDE DVD-RAMS are
> getting very inexpensive and even the top of the line (with capability
> to write CD's in addition to DVD-R* ) are under $400.00. Low end units
> are under $200.00. DVD-RAM media can be over-written for years and
> years - they say 100,000 writes and a 30 year media life. That's
> "forever" for most of us.
>
>
> At the present time, if you have more data than you can compress to 4.7
> GB (in the field I see that as typically around 9 GB), tape is obviously
> the way to go. Another reason you might need tape is speed: DVD-RAM
> isn't blindingly fast on writing - say about 3GB an hour for the units
> I've used. Otherwise, I wouldn't use tape - this is cheaper, and far
> more reliable.
>
At home, where the problem is, :-} my wife has about 4 GB of machine
embroidery stitch files and we together hav about 8 Gb of pictures, and
growing. . .
I am looking for essentially archival storage of both, which is why I am
looking at DVD-RAM. Over the years I have had too much trouble with
tapes (breaking, becoming unreadable....) and tape drives. I seem to
need to replace tape drives every 2-4 years. I just lost another Snoy
SDT-7000 that decided to not load tapes anymore. It takes the tape and
then (literally) spits it out at me. I will try power cydcling it some
day and see if that resets it, otherwise I am off to the store to get a
DVD-RAM or three.
My nightly system backup is only about 1.5 Gb, and I don't care how long
it takes so that is not a problem.
Anthony Lawrence
Keep in mind that until 5.0.7 comes out SCO Unix only supports SCSI
DVD-RAM and to make good use of it you need a program like Microlite
Edge or Lone-Tar. SCSI DVD-RAM drives are *very* hard to find right now.
Also - your picture storage is probably not compressible, so it will
take multiple cartridges to back that up. That may or may not be of
concern.
>
> My nightly system backup is only about 1.5 Gb, and I don't care how long
> it takes so that is not a problem.
Half an hour with the SCSI unit I'm using.
Bill Campbell
...
>The advantage of dvd-ram is price and longevity. IDE DVD-RAMS are
>getting very inexpensive and even the top of the line (with capability
>to write CD's in addition to DVD-R* ) are under $400.00. Low end units
>are under $200.00. DVD-RAM media can be over-written for years and
>years - they say 100,000 writes and a 30 year media life. That's
>"forever" for most of us.
BackupEdge works very well with DVD-RAM. Their FFR (Fast File Restore)
feature is virtual IFR (Instantaneous File Restore). There are limitations
of course in that everything has to fit in 4.7gb, but with Edge, that may
be extended by file-by-file compression.
>At the present time, if you have more data than you can compress to 4.7
>GB (in the field I see that as typically around 9 GB), tape is obviously
>the way to go. Another reason you might need tape is speed: DVD-RAM
>isn't blindingly fast on writing - say about 3GB an hour for the units
>I've used. Otherwise, I wouldn't use tape - this is cheaper, and far
>more reliable.
We're looking seriously at getting away from tape and DVD style backups
entirely, and using removable hard drives in their place. We're
prototyping a system here which has a Mandrake 8.2 Linux box with external
ieee1394 (FireWire) 120GB hard drives (sorry SCO/Caldera 3.1.1 Workstation
doesn't support ieee1394 reliably and I haven't received my UnitedLinux 4.0
yet :-). The external chassis and drive were about $200.00 at CompUSA, and
I have a similar LaCie 120GB on my PowerMac G4 that I paid $350.00 for
about six months ago.
We're backing up multiple systems to the external drive using rsync across
the network. Each machine has its own directory on the removable drive.
It took a couple of hours to backup our main file server's 30GB RAID
directory to this the first time, and significantly less time to do the
nightly rsync updates.
When I was in CompUSA this weekend, I saw some external chassis that
support both ieee1394 and USB 2 (not at the same time) which take any
standard IDE hard drive. I think these would be very useful if one needs
something that can be used to backup a wide variety of systems.
Yesterday I plugged an external 60GB USB 2.0 external drive into a friend's
Windows ME system so she could save off here files before reinstalling the
Windows virus.
It seems to me that hot-pluggable removable hard drives may be a much
better way to do backups than tape or CD/DVD. They're cheap, can be taken
off site easily, and allow random access to any files. It should be very
easy to initialize a new hard drive if a system has a fatal crash by
installing the new drive, partitioning, making the appropriate file
systems, copying the backup file system(s) directly to the drive, and
writing the appropriate MBR so it's bootable.
Bill
--
INTERNET: bi...@Celestial.COM Bill Campbell; Celestial Software LLC
UUCP: camco!bill PO Box 820; 6641 E. Mercer Way
FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676
URL: http://www.celestial.com/
Cutting the space budget really restores my faith in humanity. It
eliminates dreams, goals, and ideals and lets us get straight to the
business of hate, debauchery, and self-annihilation.
-- Johnny Hart
Anthony Lawrence
The problem with that is that you don't get deep backup - you can't go
back a week, a month, a year. I think it's great if it is combined with
archival backup that can be taken off-site. It's completely
unacceptable by itself.
Unfortunately, I am seeing this sort of thing promoted more and more.
As I said, it's great as long as there is also tape or dvd-ram in the
picture. Without that, somebody somewhere someday is going to be very
sad that they made this choice. I wouldn't do that for my own data and
strongly discourage anyone from it.
I recommend to my customers that they keep at least a full week worth of
tapes/cartridges and rotate one out monthly, keeping at least two months
back (and more is always better). I can't tell you how many times being
able to pull up a month old file has saved the day.
Bill Vermillion
-bill- <nob...@SpamCop.net> wrote:
>Anthony Lawrence wrote:
>> Bill Vermillion wrote:
>>
>>> In article <3e05e9aa$0$1396$2c3e...@news.voyager.net>,
>>> -bill- <nob...@SpamCop.net> wrote:
>>>
>>>> we are looking at replacing aging (and not quite adequate) DDS-2
>>>> wdrives ith DVD-RAM drives.
>>> You did not say what was not quite adequqted about the DDS-2.
>Capacity.
OK. DDS-3 or DDS-4 are direct plugins and will read all your old
tapes.
>> The advantage of dvd-ram is price and longevity. IDE DVD-RAMS
>> are getting very inexpensive and even the top of the line
>> (with capability to write CD's in addition to DVD-R* ) are
>> under $400.00. Low end units are under $200.00. DVD-RAM media
>> can be over-written for years and years - they say 100,000
>> writes and a 30 year media life. That's "forever" for most of
>> us.
No doubt that DVD-RAM is good.
>At home, where the problem is, :-} my wife has about 4 GB of
>machine embroidery stitch files and we together hav about 8 Gb
>of pictures, and growing. . .
>I am looking for essentially archival storage of both, which is
>why I am looking at DVD-RAM. Over the years I have had too much
>trouble with tapes (breaking, becoming unreadable....) and tape
>drives. I seem to need to replace tape drives every 2-4 years. I
>just lost another Snoy SDT-7000 that decided to not load tapes
>anymore.
Hm. That's not typical. Are you in a semi-dirty environment?
Are you cleaning them properly. The 7000 is pretty old, and the
9000 [dds3] was much faster.
> It takes the tape and then (literally) spits it out at me. I
>will try power cydcling it some day and see if that resets it,
>otherwise I am off to the store to get a DVD-RAM or three.
>My nightly system backup is only about 1.5 Gb, and I don't care
>how long it takes so that is not a problem.
Well there is a problem with slow backups even on nightly stores.
I you are using a SuperTar that rewinds and verified after a
bit-level backup, the DDS-2 will wear out faster than the DDS-3.
The reason is the drives are rated in hours. So if a DDS-2 take
1 hour to backup and 1 hour to verify that is two hours use
each night. While the faster speed on a DDS-3 may only take 1/2
hour for each process, therefore the DDS-3 will last longer as it
will have fewer hours of use.
I just point that out as many people seem to overlook the point
that a slower backup will wear the drives out sooner.
John DuBois
-bill- <nob...@SpamCop.net> wrote:
>>>> we are looking at replacing aging (and not quite adequate) DDS-2
>>>> wdrives ith DVD-RAM drives.
>
>embroidery stitch files and we together hav about 8 Gb of pictures, and
>growing. . .
>
>I am looking for essentially archival storage of both, which is why I am
>looking at DVD-RAM. Over the years I have had too much trouble with
>tapes (breaking, becoming unreadable....) and tape drives. I seem to
>need to replace tape drives every 2-4 years. I just lost another Snoy
>SDT-7000 that decided to not load tapes anymore. It takes the tape and
>then (literally) spits it out at me. I will try power cydcling it some
>day and see if that resets it, otherwise I am off to the store to get a
>DVD-RAM or three.
Helical-scan drives have always been problematic. SCO had enough problems
with this that eventually (years ago) everything was moved to DLT drives. I'm
told that we have yet to have a case of a DLT tape breaking or becoming
unreadable. The drives are also more robust, though they still don't live up
to the manufacturer's extreme longevity claims, possibly because of all the
shoeshining.
I just bought a Quantum DLT8000 for use at home, replacing a 20GB DLT
autochanger (a 20/40 with broken compression); I can now fit the entire system
on a single cartridge for the first time in ages. The cartridges are
unfortunately rather expensive - I probably wouldn't have gone this route if I
hadn't been given a few boxes of DLT-IV cartridges along with the
aforementioned autochanger. But, I do feel good about my data security in a
way that I never did back in the days when I used DDS drives - a restore was
always a crapshoot, and it's disturbing to have the drive eject the cartridge
with tape streaming out so it can remain wrapped around the drive guts.
I'm now experimenting with methods of reducing shoeshining, in the hope of
making the new drive last (for my modest purposes) indefinitely.
John
--
John DuBois spc...@armory.com KC6QKZ/AE http://www.armory.com/~spcecdt/
Bob Meyers
"Anthony Lawrence" <to...@pcunix.com> wrote in message
news:au7100$1kl$1...@pcls4.std.com...
> > -bill- <nob...@SpamCop.net> wrote:
> >>we are looking at replacing aging (and not quite adequate) DDS-2
> >>wdrives ith DVD-RAM drives.
>
> getting very inexpensive and even the top of the line (with capability
> to write CD's in addition to DVD-R* ) are under $400.00. Low end units
> are under $200.00. DVD-RAM media can be over-written for years and
> years - they say 100,000 writes and a 30 year media life. That's
> "forever" for most of us.
Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
The essential part of a good backup system IMO is tape rotation. So one can
buy many, low cost DDS3 ($5) or DDS4 ($12) and use a big rotation scheme.
Try having, oh say... a 20-day daily rotation + 12 monthly = 32 tapes. 32
DVD-RAMS would cost how much?
Bob Cole
> 4
> "Anthony Lawrence" <to...@pcunix.com> wrote in message
> news:au7100$1kl$1...@pcls4.std.com...
>
>>>-bill- <nob...@SpamCop.net> wrote:
>>>
>>>>we are looking at replacing aging (and not quite adequate) DDS-2
>>>>wdrives ith DVD-RAM drives.
>>>
>>The advantage of dvd-ram is price and longevity. IDE DVD-RAMS are
>>getting very inexpensive and even the top of the line (with capability
>>to write CD's in addition to DVD-R* ) are under $400.00. Low end units
>>are under $200.00. DVD-RAM media can be over-written for years and
>>years - they say 100,000 writes and a 30 year media life. That's
>>"forever" for most of us.
>
>
> Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
>
I just bought a pack of 10 for $86.99 ($7.90 each + shipping), including
shipping. These were the type 4 (9.4GB with cartridge). Larger
quantities were as little as $7.60 each. Without the cartridge were
cheaper still.
Bob Cole
Tony Lawrence
> 4
> "Anthony Lawrence" <to...@pcunix.com> wrote in message
> news:au7100$1kl$1...@pcls4.std.com...
>
>>>-bill- <nob...@SpamCop.net> wrote:
>>>
>>>>we are looking at replacing aging (and not quite adequate) DDS-2
>>>>wdrives ith DVD-RAM drives.
>>
>>The advantage of dvd-ram is price and longevity. IDE DVD-RAMS are
>>getting very inexpensive and even the top of the line (with capability
>>to write CD's in addition to DVD-R* ) are under $400.00. Low end units
>>are under $200.00. DVD-RAM media can be over-written for years and
>>years - they say 100,000 writes and a 30 year media life. That's
>>"forever" for most of us.
>
>
> Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
Gosh no.
Nothing even near that. As cheap or cheaper than tape.
--
Tony Lawrence
Free SCO and Linux Skills Tests: http://aplawrence.com/skillstest.html
Jeff Liebermann
wrote:
>Helical-scan drives have always been problematic.
I hate to agree here but I've had far too much entertainment value
from various DDS flavours to consider them reliable. I think I've hit
just about every problem possible.
1. The media doesn't last. 100 write+verify passes and they're
toast.
2. Short head life. 3ea identical Sony SDT-9000 (DDS-3) drives at
different locations. Lifetime was 1800hrs, 4000hrs, and something
like 7000hrs. The heads in the 1800hrs was apparently killed by a
dusty environment.
3. Incompatible tape formats between firmware versions. I got lucky
and was able to find an old firmware tape loader which allowed us to
read the old tapes.
4. Mechanical damage due to jammed tapes. This seem to be happening
with every vendors drives. No matter how careful one seems to be,
there seems to be one tape every 3 months that gets de-spooled inside
the drive. For HP, punch the eject button 3 times and wait 30
seconds. Then, grab the tape with a hemostat and pull.
5. Reliability on restore is dubious. Although we do a bit level
verify on every backup, I still get restore failures. The issue seems
to be head wear. The older the head, the more restore errors. If the
drive has changed (even with the same model), it's a crap shoot.
6. Mysterious driver hang issues that only happen with DDS. With
DDS, I sometimes get an unkillable tape related process that requires
a power cycle to recover. Remote power cycles in the middle of the
night are no fun. Strangely, when I switched several customers to AIT
and DLT-8000, the hangs apparently have gone away.
7. DDS-2 tapes on a DDS-3 drive seems to be a challenge. Sometimes
it works, usually it doesn't. The docs say that it should be possible
and I don't see much of a reason why I'm having problems. As usual,
it works when I don't need it, and fails when I'm trying to recover
some ancient archive file from a year old tape. I now carry an
external TapeStor 6000 (DDS-2) drive in my truck.
8. The juke boxes are junk. I have an HP-12000 DDS-2 juke box in my
office for repair. Basically, it's an turret autoloader that feeds an
ordinary DDS-2 (C1533A) drive. It jammed up so badly that I had to
disassemble the box. In the process, I discovered that the connector
between the turret and the drive had only 1/4" of slack, and would rip
the solder pads off the drive instead of disconnecting when pulling
the case apart. I've also been into a Sony TSL-7000 juke box which
has a brick like cartridge for juggling tapes. It takes longer to
initialize and juggle the tapes than to run the backup. It also fails
with mysterious drive errors that even an authorized Sony repair shop
couldn't decode. A replacement drive did the same thing.
There are others but I don't wanna try to remember them. I've almost
given up on DDS and have switched several customers to DLT-8000 and
Seagate Sidewinder AIT (200GB/tape). Both are quite reliable and have
required no attention since installation about 15 months ago.
However, media costs are outrageous. I still have some DDS-3 drives
in service and am waiting for the next disaster or head wear failure,
to justify a replacement.
I've also done some experiments with backup up to a DVD burner
(DVD+RW). However, it was attached to Windoze 2000 box that backed up
the data directories on an OSR5 box over the network using SAMBA mount
points. Speed was tolerable using FDX 100baseT thru an HP4000
ethernet switch. Gigabit ethernet would have been better, but
3.2v5.0.5 doesn't support gigabit. /root and /stand were backed up
using a compressed cpio file created before the actual backup was run.
No experience with DVD burners directly connected to the OSR5 box.
Oh yeah, happy holidaze.
--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
(831)421-6491 pgr (831)336-2558 home
http://www.LearnByDestroying.com WB6SSY
je...@comix.santa-cruz.ca.us je...@cruzio.com
-bill-
...
> I recommend to my customers that they keep at least a full week worth of
> tapes/cartridges and rotate one out monthly, keeping at least two months
> back (and more is always better). I can't tell you how many times being
> able to pull up a month old file has saved the day.
>
We also keep the monthend odd-month and even-month
we also keep the yearend for two years.
In part that is why I want to go to optical storage, for safe archival
storage.
-bill-
>>
>> Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
>
>
>
> Gosh no.
>
> Nothing even near that. As cheap or cheaper than tape.
>
>
As I was looking around for drives I found 2 sided (9 GB, uncompressed)
media for $9 each. I haven't seen any 2 sided write drives so is that,
"backup and turn over" ?
>
Tony Lawrence
Bob Meyers
"Tony Lawrence" <to...@pcunix.com> wrote in message
news:ZJrO9.506052$NH2.34773@sccrnsc01...
> >
> > Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
>
>
> Gosh no.
>
> Nothing even near that. As cheap or cheaper than tape.
>
Huh, somewhere I got the impression they were expensive. But what about your
comment that DVD-RAM are "getting real hard to find"? Does that translate to
"distributors aren't carrying them anymore"?
Negative wave.
Tony Lawrence
No. I said ** SCSI *** dvd-rams are getting hard to find. They are
making plenty of IDE dvdrams.
The problem for SCO users is that until 5.0.7, we can't use ide dvdram.
bill
> Bob Meyers wrote:
>
>> "Tony Lawrence" <to...@pcunix.com> wrote in message
>> news:ZJrO9.506052$NH2.34773@sccrnsc01...
>>
>>>> Yeah, but don't those DVD-RAM disks cost > $ 60.00 each?
>>>
>>>
>>>
>>> Gosh no.
>>>
>>> Nothing even near that. As cheap or cheaper than tape.
>>>
>>
>>
>> Huh, somewhere I got the impression they were expensive. But what
>> about your
>> comment that DVD-RAM are "getting real hard to find"? Does that
>> translate to
>> "distributors aren't carrying them anymore"?
>
>
> No. I said ** SCSI *** dvd-rams are getting hard to find. They are
> making plenty of IDE dvdrams.
>
> The problem for SCO users is that until 5.0.7, we can't use ide dvdram.
>
>
>
Bill Vermillion
John DuBois <spc...@deeptht.armory.com> wrote:
>In article <3e07273e$0$1432$2c3e...@news.voyager.net>,
>-bill- <nob...@SpamCop.net> wrote:
>>>>> we are looking at replacing aging (and not quite adequate) DDS-2
>>>>> wdrives ith DVD-RAM drives.
>>
>>At home, where the problem is, :-} my wife has about 4 GB of machine
>>embroidery stitch files and we together hav about 8 Gb of pictures, and
>>growing. . .
>>
>>I am looking for essentially archival storage of both, which is why I am
>>looking at DVD-RAM. Over the years I have had too much trouble with
>>tapes (breaking, becoming unreadable....) and tape drives. I seem to
>>need to replace tape drives every 2-4 years. I just lost another Snoy
>>SDT-7000 that decided to not load tapes anymore. It takes the tape and
>>then (literally) spits it out at me. I will try power cydcling it some
>>day and see if that resets it, otherwise I am off to the store to get a
>>DVD-RAM or three.
>Helical-scan drives have always been problematic. SCO had enough
>problems with this that eventually (years ago) everything was
>moved to DLT drives. I'm told that we have yet to have a case
>of a DLT tape breaking or becoming unreadable. The drives
>are also more robust, though they still don't live up to the
>manufacturer's extreme longevity claims, possibly because of all
>the shoeshining.
Just curious - what helical-scan devices? The first DAT/DDS was
pretty primitive and the DDS-2 was better, but IMO 4mm world
finally 'got it's act together with the DDS-3'
But during the same time when I heard people complaining about DATs
they were usually extolling the virtues of the Exabytes - an 8MM
helical format.
And the 'shoeshing' was quite often cured with things such as
the buffereing supplied in Lone-Tar and BackupEdge. If the HD's
were slow then you could not avoid shoe-shining. I remember the
first time I brought up an SCO with BE for a shop that was almost a
pure MS shop. [this was for a customer of theirs];
They wondered why the tape drive was whining. They had never heard
one that streamed before as all their MS type SW always
shoe-shined.
>But, I do feel good about my data
>security in a way that I never did back in the days when I
>used DDS drives - a restore was always a crapshoot, and it's
>disturbing to have the drive eject the cartridge with tape
>streaming out so it can remain wrapped around the drive guts.
Never had that problem. Worst I had was trying to restore a
client tape on my system as theirs was so touchy and they had no
readable backups because of HW problems. They gave me a DDS-2
tape that was broken - the person who gave me the tape didn't
know that.
Totally jammed my 96GB Seagate Scoripon 4 cart DDS-2 :-)
>I'm now experimenting with methods of reducing shoeshining, in
>the hope of making the new drive last (for my modest purposes)
>indefinitely.
The problem with the new fast tape drives is that they really show
up slower OS drive read performance.
Bill Vermillion
>> Gosh no.
>Negative wave.
Just some comments on the way things have changed over the years.
DAT was first seen as the answer to audio cassettes. Sony/Philips
were working on the CD and when they finally got it working they
pushed and pushed to get the world to accept it.
The DAT industry was having trouble making DAT work and the CD side
felt they had to get at least 5% market penetration by the time the
DAT hit the audio market and if they didn't meet that target the CD
would fail.
The DAT group finally got their audio working but then there came
the squabble from the record industry and the talk of taxes
surcharges on tape to pay for 'stolen' music. [Nothing has changed
in 20 years except now it's CD and DVD].
That delay helped the CD get a footlhold and become the faster
growing consumer device in history - until the DVD took that title
away. 5,000,000 DVD players were sold the day after Thanksgiving,
The DAT never made it in consumer audio but succedded as
mastering devices for almost all the recording studios. But DAT
was adopted for data storage and I pointed my friends
in audio to usind DAT tapes for DATA for their audio, as the
audio tapes were designed for streaming with interpolation for
missing data, while the data tapes were subjected to shoe-shine
operations and were more rugged.
Now DAT has virtually disappeared from audio as almost everyone
is using disk based recording and it's stronghold became the data
market. The first devices really weren't designed for the abuse
that data installation can give them and many people were soured
by trying to use audio DAT tapes for data.
But in today's world the DVD-RAM may be disappearing from the
data world but it's become pretty much standardized in many areas
of the film industry and Fostex has just recently released a
DVD-RAM device with time-code so audio/film/video can easily be
synchronized.
This is almost an inversion of the DAT story. So you will be able
to buy media for a long time, but I have no guess on how long
DVD-RAM devices will be produced targeted to the data storage
market. The computer market seems to want volume and price over
anyting else.
It's interesting how many things designed for one target wind up
being used in manners so different from those thought of by their
original developers.
John DuBois
>Just curious - what helical-scan devices?
DDS-1 and -2. Mine was a DDS-2.
Rainer Zocholl
>Bill Campbell wrote:
>>
>> We're looking seriously at getting away from tape and DVD style
>> backups entirely, and using removable hard drives in their place.
>> We're prototyping a system here which has a Mandrake 8.2 Linux box
>> with external ieee1394 (FireWire) 120GB hard drives (sorry
>> SCO/Caldera 3.1.1 Workstation doesn't support ieee1394 reliably and
>> I haven't received my UnitedLinux 4.0 yet :-). The external chassis
>> and drive were about $200.00 at CompUSA, and I have a similar LaCie
>> 120GB on my PowerMac G4 that I paid $350.00 for about six months
>> ago.
>The problem with that is that you don't get deep backup - you can't go
>back a week, a month, a year.
Of cause it would be a (very) stupid idea to just copy to a second disk.
The solution would be to make a daily changed storage directory
and hardlink all unchanged files from yesterday.
(And do a re-read (bit wise compare) of every single file on disc
to be aware of soft errors!)
To "rotate" files, managing weekly/monthly/yearly snapshots
"dirvish" seems to be a nice attempt (or solution? ;-)).
>I think it's great if it is combined
>with archival backup that can be taken off-site.
>It's completely unacceptable by itself.
Jepp.
I learned: use -at least- two independed ways of backups.
If your data is gone, the vendor "life time warranty" will
not help to get it back...
Of cause you can configure dirvish (etc.) to store the data over a
network off site, thru a modem, on an other continent, if you like.
(It uses rsync so the band width it not so important (but you can't do
bitwise compares)
And you can restore day-by-day file-by-file without
big bookkeeping, which file from which day is on which tape.
Too it's easy to compare two versions to the file:
You have both of them in access, or all 20 last versions.
And third:
There can't be no hardware compability problems:
You store always an "entire" unit: media and read mechanics,
not just the media and have to beg that the new drive will read
the old media...
Fouth:
It's fast, very fast.
>Unfortunately, I am seeing this sort of thing promoted more and more.
Sometime ago people were told they should buy an RAID to get
rid of any backups...
>As I said, it's great as long as there is also tape or dvd-ram in the
>picture. Without that, somebody somewhere someday is going to be very
>sad that they made this choice. I wouldn't do that for my own data
>and strongly discourage anyone from it.
There are "hotswap" IDE cases too.
Compare the price of an DLT 8000 cartridge and a 120GB harddisc...
Compare the price of a non-server PC beeing used as
an "2-Terabyte remote backup storage" off-site to a DLT drive or library...
Of cause that's no solution for every purpose, but for
"lower" data volumes worth a though (at least as "second independent
backup device" that does not need much manual care.).
>I recommend to my customers that they keep at least a full week worth
>of tapes/cartridges and rotate one out monthly, keeping at least two
>months back (and more is always better). I can't tell you how many
>times being able to pull up a month old file has saved the day.
Jepp.
have a look at dirvish.
Rainer Zocholl
>In article <3e07273e$0$1432$2c3e...@news.voyager.net>,
>-bill- <nob...@SpamCop.net> wrote:
>>Anthony Lawrence wrote:
>>> Bill Vermillion wrote:
>>>
>>>> In article <3e05e9aa$0$1396$2c3e...@news.voyager.net>,
>>>> -bill- <nob...@SpamCop.net> wrote:
>>>>
>>>>> we are looking at replacing aging (and not quite adequate) DDS-2
>>>>> wdrives ith DVD-RAM drives.
>>>> You did not say what was not quite adequqted about the DDS-2.
>>Capacity.
>OK. DDS-3 or DDS-4 are direct plugins and will read all your old
>tapes.
Attention!
DDS-4 does not read DDS-1 anymore (at least the HPs last year don't)
Tony Lawrence
> (Anthony Lawrence) 23.12.02 in /comp/unix/sco/misc:
>
>
>>Bill Campbell wrote:
>>
>>>We're looking seriously at getting away from tape and DVD style
>>>backups entirely, and using removable hard drives in their place.
>>>We're prototyping a system here which has a Mandrake 8.2 Linux box
>>>with external ieee1394 (FireWire) 120GB hard drives (sorry
>>>SCO/Caldera 3.1.1 Workstation doesn't support ieee1394 reliably and
>>>I haven't received my UnitedLinux 4.0 yet :-). The external chassis
>>>and drive were about $200.00 at CompUSA, and I have a similar LaCie
>>>120GB on my PowerMac G4 that I paid $350.00 for about six months
>>>ago.
>
>
>>The problem with that is that you don't get deep backup - you can't go
>>back a week, a month, a year.
>
>
> Of cause it would be a (very) stupid idea to just copy to a second disk.
>
> The solution would be to make a daily changed storage directory
> and hardlink all unchanged files from yesterday.
That's not reallly ideal either. It's not a bad thing to do, but it
isn't enough. The problem with this is that all your backups end up on
one piece of physical media. Lose that, and you lose everything at once.
Understand, I'm not saying that this isn't fast, convenient useful: just
that you still need tape or optical backup too.
> Jepp.
> I learned: use -at least- two independed ways of backups.
> If your data is gone, the vendor "life time warranty" will
> not help to get it back...
And one of those ways needs to be independent media, imho.