SUMMARY: backups and fsck

From: Chris Wozniak TISC (
Date: Fri Apr 28 1995 - 11:01:28 CDT

Hello Managers.

> I have a question abount fscks and dumps. It's strongly recommended
> to run fskc on all file systems to be backed up. The dumps are
> done mainly overnight, with no warm body near the computer.
> I'd like to hear how folks make sure that there are no users logged
> in and how do they do fscks on the running system.
> BTW our's is 630 MP, SunOS 4.1.3.
> I'll summarize
> Thanks in advance

I apologise for the late summary, but there was a holiday I had
to take and Easter, but here it is. I've received 13 (lucky 13:))
replies and the responders unanimously agreed that dumps without
bothering about the single user mode, unmounting FSs and fscks are OK,
provided that the backups are run during the quiet time at night.
They specifically recommended : (Gene Loriot (
   unmounting the disks using cron (Kevin Sheehan {Consulting Poster Child}):
   setting up /etc/nologin to prevent logins during a dump

Nate Itkin <> :
(...)products like BudLive from PDC. They freeze
the file system in a cache area while it's being dumped. (Peter Allan):
Try to unmount the disks, if OK dump, run fsck on unmounted disks
if wanted :
# try to unmount (will fail if in use)
# if umount succeeds, then fsck
# if fsck fails (problem with disk, then sleep and repeat fsck)
/usr/etc/umount -v /home1 && fsck /dev/rsd3a || sleep 100 && fsck /dev/rsd3a

# dump
/bin/nice -17 /usr/etc/dump 0sfa 145000 /dev/nrsmt0 /dump.arch /dev/rsd3a

# if it was unmounted then mount
/usr/etc/mount | grep "/dev/sd3a on /home1 type 4.2" || /usr/etc/mount -v /home1 (Steve Oles - KOP Sales):
We have the following software that allows you to perform
"live" backups on your SunOS 4.1.3 machines and if you like you
can contact Roger Halliday at:

We have no money for the commecial software, so I've decided to implement
a simple script, using "fuser -k <file_system>" to forcefully logout
any users (OK I'm a fashist, but it's run at 1.45 AM) and set up
a "/etc/nologin" file for the duration of the dump.

Many thanks to all who replied: (Gene Loriot ( (Greg Roberts) (Paulo Licio de Geus)
"Christopher L. Barnard" <>
Casper Dik <> (Kevin Sheehan {Consulting Poster Child})
Anchi Zhang <anchi@Starbase.NeoSoft.COM>
Nate Itkin <> (Peter Allan) (Romola Chrzanowski) (Kohler R. P. (Robert)) (Andy Feldt) (Steve Oles - KOP Sales)

Chris A. Wozniak

ph. +61 9 386 8236 e-mail fax +61 9 386 6589

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