Messages in this thread | | | Date | Fri, 7 Jul 2006 18:35:14 -0400 (EDT) | From | Justin Piszcz <> | Subject | Re: Kernel 2.6.17 and RAID5 Grow Problem (critical section backup) |
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On Sat, 8 Jul 2006, Neil Brown wrote:
> On Friday July 7, jpiszcz@lucidpixels.com wrote: >> >> Hey! You're awake :) > > Yes, and thinking about breakfast (it's 8:30am here). > >> >> I am going to try it with just 64kb to prove to myself it works with that, >> but then I will re-create the raid5 again like I had it before and attempt >> it again, I did not see that documented anywhere!! Also, how do you use >> the --backup-file option? Nobody seems to know! > > man mdadm > --backup-file= > This is needed when --grow is used to increase the number of > raid-devices in a RAID5 if there are no spare devices avail- > able. See the section below on RAID_DEVICE CHANGES. The file > should be stored on a separate device, not on the raid array > being reshaped. > > > So e.g. > mdadm --grow /dev/md3 --raid-disk=7 --backup-file=/root/md3-backup > > mdadm will copy the first few stripes to /root/md3-backup and start > the reshape. Once it gets past the critical section, mdadm will > remove the file. > If your system crashed during the critical section, then you wont be > able to assemble the array without providing the backup file: > > e.g. > mdadm --assemble /dev/md3 --backup-file=/root/md3-backup /dev/sd[a-g] > > NeilBrown >
Gotcha, thanks.
Quick question regarding reshaping, must one wait until the re-shape is completed before he or she grows the file system?
With the re-shape still in progress, I tried to grow the xfs FS but it stayed the same.
p34:~# df -h | grep /raid5 /dev/md3 746G 80M 746G 1% /raid5
p34:~# mdadm /dev/md3 --grow --raid-disks=4 mdadm: Need to backup 384K of critical section.. mdadm: ... critical section passed. p34:~#
p34:~# cat /proc/mdstat md3 : active raid5 hdc1[3] sdc1[2] hde1[1] hda1[0] 781417472 blocks super 0.91 level 5, 64k chunk, algorithm 2 [4/4] [UUUU] [>....................] reshape = 0.0% (85120/390708736) finish=840.5min speed=7738K/sec p34:~#
p34:~# mount /raid5 p34:~# xfs_growfs /raid5 meta-data=/dev/md3 isize=256 agcount=32, agsize=6104816 blks = sectsz=4096 attr=0 data = bsize=4096 blocks=195354112, imaxpct=25 = sunit=16 swidth=48 blks, unwritten=1 naming =version 2 bsize=4096 log =internal bsize=4096 blocks=32768, version=2 = sectsz=4096 sunit=1 blks realtime =none extsz=196608 blocks=0, rtextents=0 data blocks changed from 195354112 to 195354368 p34:~#
p34:~# umount /raid5 p34:~# mount /raid5 p34:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/md3 746G 80M 746G 1% /raid5 p34:~#
I guess one has to wait until the reshape is complete before growing the filesystem..? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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