On Sun, 16 Dec 2012, cwillu <cwi...@cwillu.com> wrote: > 3.2 is massively old in btrfs terms, with lots of fun little stability > and performance bugs. > > > Here is the /proc/mounts entry which shows that ssd and discard options > > are enabled. > > > > /dev/disk/by-uuid/7939c405-c656-4e85-a6a0-29f17be09585 / btrfs > > rw,seclabel,nodev,noatime,ssd,discard,space_cache 0 0 > > Don't use discard; it's a non-queuing command, which means your > performance will suck unless your device is really terrible at > garbage collection (in which case, it's just the lesser of two evils).
Thanks for the advice. On one of my systems a reinstall of the linux- image-3.6-trunk-amd64 package went from almost 4 minutes to only 29 seconds when I removed the discard option. When I then booted the 3.6.9 kernel in question the package install time dropped to 27 seconds (of which more than half was CPU time). I only did one test run of each, so 27s vs 29s could be within the range of random variation but 4 minutes vs <30s is an obvious and massive improvement. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
