On Thu, Aug 11, 2016 at 02:47:10AM +1000, Craig Sanders via luv-main wrote: >On Mon, Aug 08, 2016 at 02:05:47PM -0400, Robin Humble wrote: >> I've 8G ram which should be heaps. limiting l2arc to 1G didn't help >> either. >l2arc or arc? if l2arc, 1G isn't really worth bothering with and may >even hurt performance.
<looks through command history> echo "options zfs zfs_arc_max=$((2*1024*1024*1024))" > /etc/modprobe.d/zfs.conf >> 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, >have you tried setting zfs_arc_min = zfs_arc_max? that should stop >ARC from releasing memory for linux buffers to use. is that what most folks do? as the SSD is fast at large reads (500MB/s), I could also just cache metadata and not data. would that make sense do you think? >The most likely cause is that ext4 has excellent SSD TRIM support but >ZFS on linux doesn't. There's a patch that's (finally!) going to be >merged "soon": >https://github.com/zfsonlinux/zfs/pull/3656 neat! cheers, robin _______________________________________________ luv-main mailing list [email protected] https://lists.luv.asn.au/cgi-bin/mailman/listinfo/luv-main
