On Monday, 8 August 2016 2:05:47 PM AEST Robin Humble via luv-main wrote:
thanks for the data point. I assume that's running an old kernel though? if it's not 4.6+ then it shouldn't hit this problem. memcg is needed too % cat /proc/self/cgroup | grep mem 9:memory:/user.slice/user-XXXX.slice
3.16 is the kernel for Jessie.
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.
fair enough. I wanted to test ZFS for other reasons though - Lustre ZFS OSDs.
Why can't Lustre run on BTRFS?
BTW does btrfs still have issues when the filesystem fills? does ZFS?
It's been a long time since it has had serious issues. But there are still issues with balancing after a filesystem becomes full.
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. on my intel SSD, ZFS is noticably slower than ext4. part of it's because of ZFS's poor integration with linux's virtual memory system and both sets of caches clearly fighting each other, but presumably it's slower 'cos it has more features (eg. checksum, compression) too.
Checksums take little time on any CPU made in the last decade or so. Compression shouldn't slow it down either. The tree updates to the root of the filesystem will slow things down however and the duplicate metadata will also reduce performance. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/