On Sunday, 7 August 2016 1:58:25 AM AEST Robin Humble via luv-main wrote:
has anyone else had issues with ZFS on recent kernels and distros?
Debian/Jessie (the latest version of Debian) is working really well for me. Several systems in a variety of configurations without any problems at all. Earlier versions had ZFS sometimes not mount on boot, but that seems to have gone away.
I'm a bit of a newbie to daily use of ZFS, but I found it's fairly easy to completely lockup with lots of metadata ops (eg. du or big rsync).
I had some problems when I first started with a system that had 4G of RAM. I determined that it would be cheaper for my client to buy more RAM than to pay me to figure out why it was getting an OOM - and more RAM helps performance. Since then I haven't had a problem.
BTW this is on fedora 24 with root on ZFS, but it sounds like ubuntu has similar issues. symptoms feel like a livelock in some slab handling rather than an outright OOM. there's 100% system time on all cores, zero fs activity, no way out except to reset. unfortunately root on ZFS on a laptop means no way that I can think of to get stack traces or logs :-/
I never had ZFS work in a way that was suitable for root. I have had a number of situations where ZFS systems required the ability to boot without ZFS mounted. For the laptops I run I use BTRFS. It gives all the benefits of ZFS for a configuration that doesn't have anything better than RAID-1 and doesn't support SSD cache (IE laptop hardware) without the pain. ZFS is necessary if you need RAID-Z/RAID-5 type functionality (I wouldn't trust BTRFS RAID-5 at this stage), if you are running a server (BTRFS performance sucks and reliability isn't adequate for a remote DC), or if you need L2ARC/ZIL type functionality. For a laptop slow disk performance usually isn't a problem and ZFS probably isn't going to do much better if you have a single HDD. If you have a SSD in your laptop (which costs $200 for 500G) then BTRFS performance will be great. I wouldn't recommend using ZFS with Fedora. New releases come out too quickly and the out of tree kernel modules have more potential for breaking than regular kernel modules. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/