Network backup

[ganzsp]

Hai,
How to schedule backup of filesystems in one server on another server's tape drive.

I have s1 which has sum 20gb data's to backed up every week.but i have tape drive in server s2.how to take s1 data's backup in s2 drive in regular basis.

I have given the command

#fbackup -0 -n -u -g /etc/Den-graph-file -f xx.xxx.xx.xx:/dev/rmt/1m > /var/b
ackup-logs/full-log/full-log.`date +%d%m`.log 2>&1

were xx.xxx.xx.xx is s2's IP. I have scheduled this in s1. but it came writer aborted.

can anyone of you guide me how to schedule this task.

[Steven E. Protter · Accepted solution]

Shalom,

HP-UX does not permit tape drive sharing.

What you should do is set up an NFS share on server 1 and use server 2 with the tape drive to back up the files directly to tape with cron.

fbackup, the tool of choice depending on what type of files it is.

Serviceguard may permit tape drive sharing but I have never figured out how to make that work.

SEP

[Duncan Edmonstone]

I'm not sure what SEP is talking about here as fbackup quiet clearly states in its man page that it supports remote tape drives - here's an excerpt:

--------------------------------------
There is slightly different behavior if remote devices
are used. A device on the remote machine can be
specified in the form machine:device. fbackup creates
a server process from /usr/sbin/rmt on the remote
machine to access the tape device. If /usr/sbin/rmt
does not exist on the remote system, fbackup creates a
server process from /etc/rmt on the remote machine to
access the tape device. Only magnetic tapes can be
remote devices. When remote DDS tape devices are used,
the fast search marks capability is not used.
--------------------------------------

It doesn't however make clear that the mechanism used to start rmt on the remote system is rexec or rcmd. For these to work you must have a .rhosts trust defined for the root user between the hosts, such that s1 can run a process on s2 without asking for a password.

If you can run this on s1 without getting a password prompt or an error, it should work:

remsh s2 date

where s2 is either the hostname or IP of s2.

If it doesn't work, check on s2 whether you have an entry in the /.rhosts file for s1. It should be in the format

s1 root

again where s1 is the hostname/IP of s1

This is of course a huge security hole, as anyone with root access to s1 now also has root access to s2 (plus anyone who can spoof s1's IP address) You'll have to determine if that is acceptable.

HTH

Duncan

[ganzsp]

Hai Sep and Duncan thanx both of you.

but i'm trying as said by you.will come back shortly.

[Tim Nelson]

My experience with rmt is that the performance is a dog and you are better off purchasing another tape or use the NFS option as noted.

[ganzsp]

All thanks for your guidens,

I have made NFS and tried backup but it got failed.It's throwing writer aborted.

Have attached the error i got in log file.

I checked #ioscan -fnC tape

/dev/rmt/0m /dev/rmt/c0t3d0BESTn
/dev/rmt/0mb /dev/rmt/c0t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c0t3d0DDS
/dev/rmt/0mnb /dev/rmt/c0t3d0DDSb
/dev/rmt/c0t3d0BEST /dev/rmt/c0t3d0DDSn
/dev/rmt/c0t3d0BESTb /dev/rmt/c0t3d0DDSnb


is wat i got.

how to know which driver name has to used??

[Kyle S.]

Any of the above really,

/dev/rmt/0m /dev/rmt/c0t3d0BESTn
/dev/rmt/0mb /dev/rmt/c0t3d0BESTnb
/dev/rmt/0mn /dev/rmt/c0t3d0DDS
/dev/rmt/0mnb /dev/rmt/c0t3d0DDSb
/dev/rmt/c0t3d0BEST /dev/rmt/c0t3d0DDSn
/dev/rmt/c0t3d0BESTb /dev/rmt/c0t3d0DDSnb

/dev/rmt/c0t3d0 is the 'base device' for lack of a better term. You can use SAM to view the other devices, create new ones with specific densities, etc. They all point to the same tape drive, just with different characteristics. 'n's will be no-rewind, 'b's are Berkeley style positionings (if no b, it's AT&T style). 'm's will be typically the 'max' density's for that tape. The '0mnb' type files are really just symlinks to the /dev/rmt/c0t3d0BESTnb type actual device names.

Hope that made sense, and I didn't mangle it TOO terribly much.

[Yogeeraj_1]

hi,

can you check if on the remote host, you can backup to /dev/rmt/0m ?


revert
kind regards
yogeeraj

[Duncan Edmonstone]

The error message you get suggests one of the following:

a) There's no tape in /dev/rmt/0m
b) You have the kernel paramter st_san_safe set to 1 which prevents you from opening rewind-on-close tape drives.

Check out that you have a valid tape in the drive using the following 2 commands:

mt -f /dev/rmt/0m stat
mt -f /dev/rmt/0mn stat

If they both fail, you don't have a tape in the drive, if only the first one fails, you probably have st_san_safe set to 1.

HTH

Duncan