thought this was kind of a dumb question after I posted it, but then Ray
told me about the FCO, which I would not have known about.
thanks for the quick responses!
beckers
Original question:
I have a 250/4/266 running DU 4.0 on an internal 2 gig disk. Now I also
have a couple of external harddrives from ultrix machines. Assuming I
can build, externally hooked to the alpha, an uptodate mirror of the
current os, could I use the external drives to boot from if the internal
2 gig dies?
Answers:
From: "Alan Rollow - Dr. File System's Home for Wayward Inodes."
<alan_at_nabeth.cxo.dec.com>
Sure. Just make a backup of the essential file systems
to the other disk(s) and edit /etc/fstab of the alternate
root to reflect the alternate configuration. The hard
part is keeping the alternate system disk up to date.
What you might want to consider instead is using the other
disks as real mirrors using LSM. It works best if the
other disk is also 2 GB, but I think LSM can build a mirror
from multiple devices.
From: Tom Ozanich <txo_at_esca.com>
To make a long story short; yes. After you have built your new drive you
can boot from it by:
>>> boot dkax00
where x is the id of the drive that you wish to boot from.
you would have to change the /etc/fstab file to reflect any changes in
drives/file systems.
From: "Raymond A. Browder" <browder_at_det.dec.com>
I don't see any reason why you can't. But check the supported hw on
the DU SPD. Also, what SCSI adapter are you using for the external
SCSI bus?
You may want to zero out and rebuild the disklabel so that the system
does not use the old ULTRIX disklabel.
BTW, If these disks are RZ57's, you will need to get a FCO for the disks.
Otherwise, you can/will lose data.
FCO -> Field Change Order.
There is a chip that needs to be replaced on the 57's to make them work
right on the alphas.
From: Greg Sorensen <SorensenG_at_mail.dec.com>
Yes. If the drives were identical, you could use dd to copy them
over. Since I bet they are not, you should use dump and restore.
Be aware that you may have to rebuild the kernel on the second
disk so that it refers to the correct scsi addresses for things
like primary swap. You will also have to change fstab. That is
assuming you want to keep the spare drive at a different scsi
address. If you are willing to re-jumper the spare drive to be
at the same address as the failed main drive, then you can skip
that stuff. This also means, of course, that you would have to
pull out the bad main drive to avoid scsi conflicts.
Also be aware that the RZ57 needed a firmware upgrade to function
properly on alphas (if that happens to be what your spare drives
are). Without the new firmware undetected data corruption errors
can occur. All the other older drives, back to the RZ56 I believe,
should work and are supported.
From: Scott Johnson <scott_at_dsuper.net>
By default SCSI cards take the lowest ID to boot from. If the backup
external drive was the next ID up from the internal, then it should work.
The only problem is if you have a terminator running on the internal you
will have to invoke the one on your controler.
Received on Tue Jul 29 1997 - 00:40:10 NZST