[Gluster-users] performance tuning?
wdaniels at neomentis.net
Wed Dec 21 16:35:15 UTC 2011
On 21/12/11 14:26, Jeff White wrote:
> I'm going to run into the 'lots of small files on replica sucks' problem.
Good luck! I found it is not the performance so much that is the
problem, but the consequential system load on the bricks with many small
I found that copying 3 large IMAP accounts simultaneously to a new
server having Maildirs on gfs (one brick hosted on a different server,
16-core 32GB machine with two 1.5TB SATA drives configured in RAID 10,
gigabit ethernet) created such I/O load on the brick server as to bring
it to it's knees (uptime load numbers around 80-90) despite CPU load
closer to 5%.
A couple of very small VMs running on the brick server were just
completely choked. I tried a couple of gfs tuning options with no
In my case it was an quick conclusion to just use an IMAP proxy and
stick to local storage, though I did wonder afterwards if perhaps the
local I/O got choked because there were 16 cores to run gluster threads
in parallel. If it is possible to restrict gluster's thread count, maybe
it would have worked better?
And I guess with greater distribution across bricks the load would be
shared between the disk I/O potential of many more machines. I'd be
interested to hear more experienced views on these things.
More information about the Gluster-users