I wanted to confirm that btrfs will continue to work on raid1 when one
of devices will be gone.
dd if=/dev/null of=img0 bs=1 seek=2G
dd if=/dev/null of=img1 bs=1 seek=2G
mkfs.btrfs -d raid1 -m raid1 img0 img1
losetup /dev/loop1 img0
losetup /dev/loop2 img1
mkdir dir
mount -t btrfs /dev/loop1 dir
btrfs device scan
mount -t btrfs /dev/loop1 dir
echo abc > dir/a.txt
umount dir
losetup -d /dev/loop2
btrfs device scan
mount -t btrfs /dev/loop1 dir
mount: wrong fs type, bad option, bad superblock on /dev/loop1,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
am I missing some nuance?
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On 07/11/2011 08:22 PM, krzf83@gmail.com wrote:> I wanted to confirm that btrfs will continue to work on raid1 when one > of devices will be gone. > > dd if=/dev/null of=img0 bs=1 seek=2G > dd if=/dev/null of=img1 bs=1 seek=2G > mkfs.btrfs -d raid1 -m raid1 img0 img1 > losetup /dev/loop1 img0 > losetup /dev/loop2 img1 > mkdir dir > mount -t btrfs /dev/loop1 dir > btrfs device scan > mount -t btrfs /dev/loop1 dir > echo abc> dir/a.txt > umount dir > losetup -d /dev/loop2 > btrfs device scan > mount -t btrfs /dev/loop1 dir > mount: wrong fs type, bad option, bad superblock on /dev/loop1, > missing codepage or other error > In some cases useful info is found in syslog - try > dmesg | tail or so > > am I missing some nuance?Yeah you need to mount -o degraded. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Thanks. I don''t see reason why this needs another mount switch. This would fail to start whole system in / parition was btrfs raid1, with no reason to do so. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html