Hi,
I''ve been looking at a raidz using opensolaris snv_111b and
I''ve come
across something I don''t quite understand. I have 5 disks (fixed size
disk images defined in virtualbox) in a raidz configuration, with 1 disk
marked as a spare. The disks are 100m in size and I wanted simulate data
corruption on one of them and watch the hot spare kick in, but when I do
dd if=/dev/zero of=/dev/c10t0d0 ibs=1024 count=102400
The pool remains perfectly healthy
pool: datapool
state: ONLINE
scrub: scrub completed after 0h0m with 0 errors on Wed Oct 21 17:12:11
2009
config:
NAME STATE READ WRITE CKSUM
datapool ONLINE 0 0 0
raidz1 ONLINE 0 0 0
c10t0d0 ONLINE 0 0 0
c10t1d0 ONLINE 0 0 0
c10t2d0 ONLINE 0 0 0
c10t3d0 ONLINE 0 0 0
spares
c10t4d0 AVAIL
errors: No known data errors
I don''t understand the output, I thought I should see cksum errors
against c10t0d0. I tried exporting/importing the pool and scrubbing it
incase this was a cache thing, but nothing changes.
I''ve tried this on all the disks in the pool with the same result and
the datasets in the pool is uncorrupted. I guess I''m misunderstanding
something fundamental about ZFS, can anyone help me out and explain.
-Ian.
z
On Oct 21, 2009, at 5:18 PM, Ian Allison wrote:> Hi, > > I''ve been looking at a raidz using opensolaris snv_111b and I''ve > come across something I don''t quite understand. I have 5 disks > (fixed size disk images defined in virtualbox) in a raidz > configuration, with 1 disk marked as a spare. The disks are 100m in > size and I wanted simulate data corruption on one of them and watch > the hot spare kick in, but when I do > > dd if=/dev/zero of=/dev/c10t0d0 ibs=1024 count=102400Should be: of=/dev/c10t0d0s0 ZFS tries to hide the slice from you, but it really confuses people by trying to not be confusing. -- richard> > The pool remains perfectly healthy > > pool: datapool > state: ONLINE > scrub: scrub completed after 0h0m with 0 errors on Wed Oct 21 > 17:12:11 2009 > config: > > NAME STATE READ WRITE CKSUM > datapool ONLINE 0 0 0 > raidz1 ONLINE 0 0 0 > c10t0d0 ONLINE 0 0 0 > c10t1d0 ONLINE 0 0 0 > c10t2d0 ONLINE 0 0 0 > c10t3d0 ONLINE 0 0 0 > spares > c10t4d0 AVAIL > > errors: No known data errors > > > I don''t understand the output, I thought I should see cksum errors > against c10t0d0. I tried exporting/importing the pool and scrubbing > it incase this was a cache thing, but nothing changes. > > I''ve tried this on all the disks in the pool with the same result > and the datasets in the pool is uncorrupted. I guess I''m > misunderstanding something fundamental about ZFS, can anyone help me > out and explain. > > -Ian. > z > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
On Oct 22, 2009, at 4:18, Ian Allison <iana at pims.math.ca> wrote:> Hi, > > I''ve been looking at a raidz using opensolaris snv_111b and I''ve > come across something I don''t quite understand. I have 5 disks > (fixed size disk images defined in virtualbox) in a raidz > configuration, with 1 disk marked as a spare. The disks are 100m in > size and I wanted simulate data corruption on one of them and watch > the hot spare kick in, but when I do > > dd if=/dev/zero of=/dev/c10t0d0 ibs=1024 count=102400 > > The pool remains perfectly healthyTry of=/dev/rdsk/c10t0d0s0 and see what happens Victor> pool: datapool > state: ONLINE > scrub: scrub completed after 0h0m with 0 errors on Wed Oct 21 > 17:12:11 2009 > config: > > NAME STATE READ WRITE CKSUM > datapool ONLINE 0 0 0 > raidz1 ONLINE 0 0 0 > c10t0d0 ONLINE 0 0 0 > c10t1d0 ONLINE 0 0 0 > c10t2d0 ONLINE 0 0 0 > c10t3d0 ONLINE 0 0 0 > spares > c10t4d0 AVAIL > > errors: No known data errors > > > I don''t understand the output, I thought I should see cksum errors > against c10t0d0. I tried exporting/importing the pool and scrubbing > it incase this was a cache thing, but nothing changes. > > I''ve tried this on all the disks in the pool with the same result > and the datasets in the pool is uncorrupted. I guess I''m > misunderstanding something fundamental about ZFS, can anyone help me > out and explain. > > -Ian. > z > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss