[Gluster-users] [SPAM?] Re: single storage server

[Tomasz Chmielewski]

On 06.05.2011 18:17, Whit Blauvelt wrote:
> On Fri, May 06, 2011 at 06:06:02PM +0200, Tomasz Chmielewski wrote:
>
>> Read access should be fine though (with noatime mount), and
>> shouldn't break things?
>
> Nice question.
>
> Even if it is safe to only read (seems it should be), does mounting through
> fuse add enough system load to be worth not using? Or is this just about
> saving the moment of labor needed to do the mount?

It's not just "fuse add enough system load" - it's the extra work 
glusterfs does.

I.e. when reading any file, it sends stat() to every gluster server I 
think, for that file.

Try doing this experiment, with these assumptions:

/data   - directory containing the files physically
/shared - mounted gluster volume


The directories should be big enough (i.e. so that ls -lR /data takes at 
least 20 secs).

time ls -lR /data 1>/dev/null

time ls -lR /shared 1>/dev/null


You'll see how much overhead glusterfs is!


-- 
Tomasz Chmielewski
http://wpkg.org