On Wed, 8 Jun 2005, Jon LaBadie wrote:
> On Wed, Jun 08, 2005 at 01:43:25PM +0100, Tom Brown wrote:
> > Not entirely and only related to amanda but i'm sure people have done 
> > this before so here we go ;)
> > 
> > Linux amanda server (WBEL4) and its using filedriver for virtual tapes 
> > as client does not want to spend $$$ on an LTO3 drive - a LOT of data here.
> > 
> > So anyone used USB2/Firewire external HDD's as their virtual tapes? How 
> > does amanda/Linux handle this? I presume that amanda does not really 
> > care and that this is prehaps more a Linux question but any gotchas? 
> > makes to avoid? Does Linux mind hotplugging?
> 
> Only a single experience, for a client that wanted to transport
> a pair of external drives back and forth from office to home as
> "off-site" protection.  This was RHEL 3 and plugging them in
> did not seem to be a problem, they mounted whenever they were
> plugged it or powered up.  But it was not as if we actively
> tested regularly plugging/unplugging.  The original plan was
> weekly, so that was not an issue.

Right now I'm using such a scheme, using IDE disks in `hot-pluggable'[*] IDE
bays.

> One thing that did happen to me during testing.  I plugged the
> drives in one at at time and converted the disks to ext format.
> Then began some testing.  Later the client rebooted and I did
> not realize it.  I blindly continued some testing where the
> first step was to clean out one of the drives (rm -rf /mnt/usb1/*
> or some such).  What I did not realize that across the reboot
> what had been usb1 was now usb2 and visaversa.  It depended on
> the order they were seen by the OS.
> 
> It was time to experiment with something I had read about RHEL,
> maybe other linux's too, that a drive can be assigned a unique
> id, and whenever that id is seen, it can be made to automount
> on the same directory.  Set it up and it worked like a charm.

I gave the partitions on my backup disks labels using cfdisk, and use different
mount points. In /etc/fstab I have

| LABEL=backup-disk-1     /media/backup1  ext3    defaults,noauto 0       0
| LABEL=backup-disk-2     /media/backup2  ext3    defaults,noauto 0       0

I.e. the right disk will always show up at the right mount point.

My removable disks are much larger than my vtapes, so from time to time I copy
my vtapes (which reside on an internal non-removable disk) to a removable disk.

Right now all this is done manually, but my intention is to write some scripts
to automate managing vtapes on multiple removable disks.

Gr{oetje,eeting}s,

                                                Geert

[*] I'm aware of the unsafeness of hot-plugging PATA disks. So far it worked
    fine (minus problems if you try to mount a disk after you removed the old
    one, but before you inserted the new one). In the future I plan to use USB2
    or IEEE1394 disks.
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert AT linux-m68k 
DOT org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                                            -- Linus Torvalds