Thanks Jim Moving to correct ovirt-node mailing list (node-devel@xxxxxxxxx) On Wed, 2012-01-18 at 14:44 +0100, Jim Meyering wrote: > [Following up on this thread: > http://thread.gmane.org/gmane.linux.kernel.device-mapper.devel/14999] > > Alasdair G Kergon wrote: > > Try > > blkdev --flushbufs > > after any cmd that writes to a dev to see if that makes any difference. > > Thanks for the work-around. > Using "blockdev --flushbufs $dev" does indeed make parted > behave the same with dm-backed storage as with other devices. > > Adjusting my small example, > > cd /tmp; truncate -s 10m g && loop=$(losetup --show -f g) > echo 0 100 linear $loop 0 | dmsetup create zub > dev=/dev/mapper/zub > parted -s $dev \ > mklabel gpt \ > mkpart efi 34s 34s \ > mkpart root 35s 35s \ > mkpart roo2 36s 36s \ > u s p > blockdev --flushbufs $dev # FIXME: required with device-mapper-1.02.65-5 > > # write random bits to p1 > dd of=${dev}p1 if=/dev/urandom count=1 > dd if=${dev}p1 of=p1-copy.pre count=1 > parted -s $dev mkpart p4 37s 37s > blockdev --flushbufs $dev # FIXME: required with device-mapper-1.02.65-5 > > dd if=${dev}p1 of=p1-copy.post count=1 > cmp -l p1-copy.pre p1-copy.post > > With that, the "cmp" show no differences. > > Does this sound like a problem in device-mapper land, > or in how parted interacts with DM? > > _______________________________________________ > ovirt-devel mailing list > ovirt-devel@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/ovirt-devel -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
