On Fri, Jan 24, 2020 at 11:36:45PM +1100, Russell Coker wrote:
I've put some simple BTRFS and ZFS training exercises at the above URLs
(this is the training that was done at a LUV Saturday meeting in 2015). As
they involve deliberately corrupting data to exercise the filesystems it's a
good idea to to this on a VM so a typo won't cause problems.
If you ever do an update of these, I'd suggest adding snapshot & send/receive
exercises because doing backups with snapshots is one of the best features of
both btrfs and zfs - better than rsync in a tiny fraction of the time (minutes
vs hours). This would require two pools so add, e.g., /dev/vd[fgh] virtual
drives to the VM. Or run two VMs to show remote send/receive via ssh. 100 or
200 MB each is enough for each pool drive.
BTW, I noticed two minor problems with the zfs instructions:
First is that you tell the reader to add the buster-updates contrib repo
to sources.list, then tell them to install spl-dkms and zfs-dkms from
This should probably add the buster-backports repo instead:
buster-backports contrib main
The second is that spl-dkms is no longer needed with zfs 0.8 and above, it's a
dummy package. buster-backports contains zfs 0.8.2
Getting rid of spl-dkms doesn't make it any faster to install & compile the
zfs module - most of what was in spl-dkms has been folded into zfs-dkms.
(on my threadripper 1950x box, it takes about a minute or a minute and a half
to compile the zfs module. on my older Phenom II and FX-8xx0 boxes, it takes
around 5 minutes)
BTW, zfs 0.8.3 just arrived in unstable/sid. the NEWS.Debian.gz file says:
zfs-linux (0.8.3-1) unstable; urgency=medium
The SIMD acceleration has been fixed in this upstream release.
Users could use the following two commands to double check:
$ cat /sys/module/zfs/parameters/zfs_vdev_raidz_impl
$ cat /sys/module/zcommon/parameters/zfs_fletcher_4_impl
Another notable change is the parallelization of the KABI checks
during the configure stage, which may significantly boost the
postinst stage of zfs-dkms that builds the kernel module.
-- Mo Zhou <lumin(a)debian.org> Sat, 25 Jan 2020 13:26:02 +0800
I just upgraded my ztest VM to this today. Compiled and rebooted
without problem. Will upgrade my actual machines over the next few
days or so.
craig sanders <cas(a)taz.net.au>