[Gluster-users] GlusterFS performance

[Toby Corkindale]

On 01/03/13 21:12, Brian Candler wrote:
> On Fri, Mar 01, 2013 at 03:30:07PM +0600, Nikita A Kardashin wrote:
>>     If I try to execute above command inside virtual machine (KVM), first
>>     time all going right - about 900MB/s (cache effect, I think), but if I
>>     run this test again on existing file - task (dd) hungs up and can be
>>     stopped only by Ctrl+C.
>>     Overall virtual system latency is poor too. For example, apt-get
>>     upgrade upgrading system very, very slow, freezing on "Unpacking
>>     replacement" and other io-related steps.
>>     Does glusterfs have any tuning options, that can help me?
>
> If you are finding that processes hang or freeze indefinitely, this is not
> a question of "tuning", this is simply "broken".
>
> Anyway, you're asking the wrong person - I'm currently in the process of
> stripping out glusterfs, although I remain interested in the project.
>
> I did find that KVM performed very poorly, but KVM was not my main
> application and that's not why I'm abandoning it.  I'm stripping out
> glusterfs primarily because it's not supportable in my environment, because
> there is no documentation on how to analyse and recover from failure
> scenarios which can and do happen. This point in more detail:
> http://www.gluster.org/pipermail/gluster-users/2013-January/035118.html
>
> The other downside of gluster was its lack of flexibility, in particular the
> fact that there is no usage scaling factor on bricks, so that even with a
> simple distributed setup all your bricks have to be the same size.  Also,
> the object store feature which I wanted to use, has clearly had hardly any
> testing (even the RPM packages don't install properly).
>
> I *really* wanted to deploy gluster, because in principle I like the idea of
> a virtual distribution/replication system which sits on top of existing
> local filesystems.  But for storage, I need something where operational
> supportability is at the top of the pile.

I have to agree; GlusterFS has been in use here in production for a 
while, and while it mostly works, it's been fragile and documentation 
has been disappointing. Despite 3.3 being in beta for a year, it still 
seems to have been poorly tested. For eg, I can't believe almost no-one 
else noticed that the log files were busted.. nor that the bug report 
has been around for quarter of a year without being responded to or fixed.

I have to ask -- what are you moving to now, Brian?

-Toby