On Fri, Nov 20, 2009 at 02:05:01AM +0000, Pedro Ribeiro wrote:
> And on /etc/fstab mount it as;
> /dev/mapper/target noatime,logbufs=8,logbsize=256k
> After the above, my delete speed improved drastically.
That would be the logbsize option your specified - logbufs=9 is the
> Searching around the net I was able to find that using "lazy-count=1"
> on mkfs would give a performance increase - how much would that be,
> enough for me to do a full backup, format with that option + 128m log
> and then restore all again?
It depends on your workload. If you are doing lots of stuff in
parallel, then it makes a big difference because it removes the
superblock as a single point of contention. It also has the effect
of reducing the latency of fsync() if allocation was required.
Neither will affect typical desktop workloads unless you are
doing multi-media work, in which case the latency reduction of
lazy-count=1 make a big difference.
> And anything else you recommend?
No, the defaults set most of the best options for performance.
We probably should set lazy-count=1 as the default now that most
distros have picked up kernels that support that option now.