[Gluster-users] gluster 3.2.0 - totally broken?

Stephan von Krawczynski skraw at ithnet.com
Sat May 21 08:33:22 UTC 2011


On Fri, 20 May 2011 17:01:22 +0200
Tomasz Chmielewski <mangoo at wpkg.org> wrote:

> On 20.05.2011 15:51, Stephan von Krawczynski wrote:
> 
> > most of them are just an outcome of not being able to find a working i.e. best
> > solution for a problem. cache-timeout? thread-count? quick-read?
> > stat-prefetch? Gimme a break. Being a fs I'd even say all the cache-size paras
> > are bogus. When did you last tune the ext4 cache size or timeout? Don't come
> > up with ext4 being kernel vs. userspace fs.  It was their decision to make it
> > userspace, so don't blame me. As a fs with networking it has to take the
> > comparison with nfs - as most interested users come from nfs.
> 
> Ever heard of fsc (FS-Cache),

To my knowledge there is no persistent (disk-based) caching in glusterfs at
all ...

> acreg*, acdir*, actimeo options for NFS?

... as well as options only dealing with caching of file/dir attributes.
You are talking about completely different things here. If you want to argue
about that you should probably _request_ these types of options additionally
to the already existing ones.
 
> Yes, they are related to cache, and oh, NFS is kernelspace. And yes, 
> there are tunable timeout options for NFS as well.

The only reasonable configurable timeout in nfs is the rpc timeout.

> As of timeout options with ext4, or any other local filesystem - if you 
> ever used iSCSI, you would also discover that it's recommended to set 
> reasonable timeout options there as well, depending on your network 
> infrastructure and usage/maintenance patterns. "Incidentally", iSCSI is 
> also kernelspace.

And is it "incidentally" as slow as glusterfs in the same environment? Not?
And did you ever manage to hard freeze your boxes with it? To show double
files? Not being able to open existing files? Wrong filedates? Wrong UIDs/GIDs?
Shall I continue to name problems we saw through all tested versions of
glusterfs? I don't because I dropped the idea that it would be helpful at all.
If you want to share helpful information tell us how you would
default-configure glusterfs so it is equally performing to nfs in most cases.
If you can't, what is your point then?

> -- 
> Tomasz Chmielewski
> http://wpkg.org

-- 
Regards,
Stephan



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