Hi!
Job to do: filesytem tranfer fom one raid to another / backup a server of
about 1TB data and restore.
This Senario:
Server: Ubuntu 6.06 LTS + own xfs-fixed kernel 2.6.17.7
Backup: Ubuntu 6.06 LTS + own xfs-fixed kernel 2.6.17.7
Network 1Gbit Copper
xfsdumped server like this:
1. logged into the backup system
1a. dumped the XFS Filesystem like that:
> ssh server "xfsdump -l 0 -F -L transfer -M server_backup" - /dev/sdb1" >
> /backup//backup/server_sdb1_xfsdump
Worked fine. Rsult was:
-rw-rw-r-- 1 root root 568776542496 2006-08-10 15:16
/backup/backup-server_sdb1_xfsdump
But the ssh transfer has got an big overhead off cpu (comression, evcryption),
so the dump
was not fast as expected, it took about 2 days.
So I decided to drop the overhead and to use a NFS link on the restore side.
2. Now I exchanged the old Hardware Raid on the server and started from Knoppix
V5.01
(see:
http://ftp.freenet.de/pub/ftp.uni-kl.de/pub/linux/knoppix/KNOPPIX_V5.0.1CD-2006-06-01-DE.iso
http://ftp.freenet.de/pub/ftp.uni-kl.de/pub/linux/knoppix/KNOPPIX_V5.0.1CD-2006-06-01-EN.iso)
Knoppix Booted using "knoppix 2"
2a. created anf formated partitions, sda1, sda2 (sda2 for swap, 4 GN or so.
aktivated swap);
mounted the fresh XFS partiton to /mnt
2b. made NFS link to Backup server up (started portmap and mounted the
backup:/backup/)
2c. started xfsrestore like that
xfsrestore -f /backup/backup-server_sda1_xfsdump /mnt/
After about a few hours xfsrestore quitted with a failure: "Too much open
files", Abort
The restore Process failed after ca. 66G of 500G.
OK, I raised the Kernel Openfile MAX, echo 524288 > /proc/sys/fs/file-max
and tried again.
xfsrestore -f /backup/backup-server_sda1_xfsdump /mnt/
Same error at same place.
Version was: xfsrestore: version 2.2.36 (dump format 3.0)
Can s.o. confirm this ?
A working around was to use the much slower ssh pipe construct:
2d.
root@Knoppix[~]# ssh backup "dd if=/backup/backup-server_sda1_xfsdump bs=10M" |
xfsrestore - /mnt/
This works.
Since that the last restore works, I think there is a bug in xfsrestore or
xfs/nfs in the kernel 2.6.17.
Backupserver, Server, Knoppix are bugfixed 2.6.17(.7). Restoring the dump via
nfs failed due "too much open files".
Does xfsrestore opens really 512k files ? I do not belive that.
So It could a problem in Kernel or NFS Stack be the problem.
Can any one confirm this behavior ? (to make it better next time)
Greetings from Northern Germany
Jürgen Sauer
--
Jürgen Sauer - AutomatiX GmbH, +49-4209-4699, jojo@xxxxxxxxxxxx
Das Linux Systemhaus - Service - Support - Server - Lösungen
http://www.automatix.de OpenOffice erhalten Sie hier kostenfrei
http://de.openoffice.org/
|