Linux – xfsdump: Spanning multiple drives

backuplinuxxfs

I'm trying to create a one-off snapshot of 5.5TB of data to 3 external 2TB drives. The data is on an XFS partition, so the logical option seemed to be xfsdump, as it can span multiple devices. As a test, I've created a number of smaller partitions on one of the drives so I can force it to reach the end of the drive in minutes instead of hours. The external drive contains two partitions, /dev/sde1 and /dev/sde2, both 256MB in size.

This is the command I'm using:

xfsdump -o -l0 -s daily.0/jones -f /dev/sde2 -p 10 /snaps

I'm prompted for dump and media labels and the backup begins. After around 30 seconds, I get these messages:

xfsdump: ending media file
xfsdump: media file size 750000128 bytes
xfsdump: dump size (non-dir files) : 728189552 bytes
xfsdump: NOTE: dump interrupted: 27 seconds elapsed: may resume later using -R option
xfsdump: Dump Status: INTERRUPT

That's pretty much what I was hoping to see, as it hit the end of the available space on /dev/sde2.

Running xfsdump -I looks good, too:

# xfsdump -I
file system 0:
        fs id:          767465ce-3031-4672-8341-dfb135d8a463
        session 0:
                mount point:    broze:/snaps
                device:         broze:/dev/mapper/vg0-snaps
                time:           Tue Nov  3 14:23:57 2009
                session label:  "dump1"
                session id:     531a3622-84af-4767-a54b-a1b11a962dcb
                level:          0
                resumed:        NO
                subtree:        YES
                streams:        1
                stream 0:
                        pathname:       /dev/sde2
                        start:          ino 535 offset 0
                        end:            ino 1260 offset 0
                        interrupted:    YES
                        media files:    1
                        media file 0:
                                mfile index:    0
                                mfile type:     data
                                mfile size:     750000128
                                mfile start:    ino 535 offset 0
                                mfile end:      ino 1260 offset 0
                                media label:    "drive1"
                                media id:       721c35ba-e844-47f8-8692-0d3122d88093
xfsdump: Dump Status: SUCCESS

Seems to indicate I should be able to resume the backup. However, if I run xfsdump with the -R flag and specify a new device to backup to, this is what I get:

# xfsdump -R -o -l0 -s daily.0/jones -f /dev/sde1 -p 10 /snaps
xfsdump: using file dump (drive_simple) strategy
xfsdump: version 2.2.45 (dump format 3.0) - Running single-threaded

 ============================= dump label dialog ==============================

please enter label for this dump session (timeout in 300 sec)
 -> dump1.contd
session label entered: "dump1.contd"

 --------------------------------- end dialog ---------------------------------

xfsdump: ERROR: resume (-R) option inappropriate: no interrupted level 0 dump to resume
xfsdump: Dump Status: ERROR

The /dev/sde2 partition does appear to contain a valid, if incomplete, backup as I can restore from it using the xfsrestore command.

Any idea how I can get xfsdump to span multiple devices? Is there a better way to accomplish this without manually trying to partition the data into 2TB chunks?

Thanks!

Best Answer

This is tricky. First I don't think I would recommend doing this if at all possible. Secondly, its probably better to back up just the data in chunks versus the file system. If however you must back it up as one continuous file system I would imagine you could create an lvm2 volume spanning your three drives as a virtual container of sorts and then pretty much dd/xfsdump the whole thing into it. Not sure if this is a reasonable approach but it should work. :)

Good luck

Related Topic