> PC servers still use SCSI today, they use bigger SCSI hard disks
> such as 20GIG 30GIG 40GIG 60GIG 80GIG.
The most common sizes are (or were): 1, 2, 4, 9, 18, 36 GB, and a few
sizes above 36 GB.
Earlier drives had less than 1 GB per platter.
The 1, 2 and 4 GB drives had 1 GB per platter.
The 9, 18 and 36 GB drives had 9 GB per sets of platters.
Above 36 GB things got to be rather specialized, with 68 GB drives
appearing in 10,000 rpm models (the others I mentioned were generally
7,200 rpm models, the Barracudas; the 10K models were Cheetahs).
To be useful on an old Mac two things are required: a 68-to-50 or an
80-to-50 pin adapter (but 1, 2 and 4 GB were commonly available in 50
pins as well), and an initializer which can partition the drive into
2 GB partitions.
Drive Setup can do this, but it supports a maximum of eight
partitions, unless it is substantially modified. Drive Setup is
easily modified to support otherwise unsupported drives. Just take a
supported Seagate model and duplicate its device data using ResEdit.
Once you get up to System 8.1, matters get a little better, and 8.6
is much more flexible than 8.1 or 8.5.1.
System 9 better still with large drives.
Larger hard disk's are too high technology for these legacy, outdated Machine's; however though if you format the ROM drive in these machines and install OS X hard disk management software it may be possible to bypass the NuBus SCSI image controller and actually install The Large Disk drive you've been fantasizing about; theoretically installing 15k and 10k SCSI drives larger than 2 GigaRAM. I would be careful though, machines this old have been known to burst into flames when trying to upgrade them.
Greetings, Antonio Rodríguez (Grijan) -- Galería fotográfica: <http://www.flickr.com/photos/ajgelado/> Blog: <http://tecnousuario.blogspot.com/>
> 2) If you want to run any Mac OS prior to 8.1, you have to divide
> the drive into 2 GB partitions. A 15 GB drive would, thus, appear
> as eight logical drives in the desktop (seven of them of 2 GB, and
> the eighth of 1 GB). This can limit the portion of the drive you
> can *use*, but if you can't get a smaller drive, you can leave part
> of it unused. If you run Mac OS 8.1 or 9.x, IIRC, you have to have
> a boot/System partition of 2 GB or less, and can cover the
> remainder of the disk with just other huge partition.
8.0 had master only support, for those Macs, the Beiges, in
particular, which featured IDE drives for the standard drives, but
which also supported SCSI for the optional internal Zip and any
external drive.
8.1 added slave support to 8.0. Drive Setup was appropriately
changed. At this point, the Beige's ROM had been fixed, and slaves
were now supported, so that any optional internal Zips were IDE, not
SCSI. SCSI was still supported for external drives.
8.5.1 and 8.6 were greatly improved versions of the basic MacOS 8 theme.
As a practical matter, 2 GB partitions makes sense for any disk drive
in this generation of Macs, as the largest capacity external backup
device was a 2 GB DDS drive.
Anyway, backup tape size doesn't matter much these days, because I doubt
anybody would use it to backup any computer: it's easier and faster to
use an Ethernet or LocalTalk network and set up an FTP server in a
computer with a bigger hard drive. And even faster (and relatively
cheap) to buy an external SCSI hard drive and have two copies of all
important data.
Greetings,
Antonio Rodríguez (Grijan)
--
Galería fotográfica: <http://www.flickr.com/photos/ajgelado/>
Blog: <http://tecnousuario.blogspot.com/>
PeterH escribió:
The matter of backups is a delicate one. A backup isn't useful if it
isn't updated frequently, and asking anybody to spend all Friday
afternoons doing the customary tape backup rotation when they could be
on a walk with their children is almost like inviting them not to have a
backup at all. IMHO, having an on-site up-to-date backup is far more
important than having an (poorly updated) offsite one (what's more
probable, a fire, an earthquake, or a hard drive failure?). Thus, I have
developed this small program that automatically updates a main directory
with a copy of itself on another drive, several times a day if you want.
That way, my clients can have always an update, in case the hard drive
fails, the OS corrupts something, or the user accidentally deletes or
breaks something (my backup program is for Windows, but is free for
anybody who wants it - just write me). Of course, there are other
programs that do it also, and you can do the same using only Finder or
Explorer.
Of course, other methods (burning to CD/DVD/BlueRay, ZIPs, backup tapes,
even floppy disks!) work also, and everyone should choose what fits
him/her better. That's why there are several different methods.
Greetings,
Antonio Rodríguez (Grijan)
--
Photo gallery: <http://www.flickr.com/photos/ajgelado/>
Blog: <http://tecnousuario.blogspot.com/>