[Gluster-users] Reading directly from brick

Reinis Rozitis r at roze.lv
Tue Sep 6 20:24:24 UTC 2011


> Simple answer - no, it's not ever safe to do writes to an active Gluster 
> backend.

Question was about reads though and then the answer is it is perfectly fine 
(and faster) to do reads directly from the filesystem (in replicated setups) 
if you keep in mind that by doing so you lose the Glusters autoheal 
eature  - eg if one of the gluster nodes goes down and there is a file 
written meanwhile when the server comes up if you access the file directly 
it won't show up while it would when accessing it via the gluster mount 
point (you can work arround it by manually triggering the self heal).


> I've heard that reads from glusterfs are around 20 times slower than from 
> ext3:

"20 times" might be fetched out of thin air but of course there is a 
significant overhead of serving a file from a gluster which basically 
involves network operations and additional meta data checks versus fetching 
the file directly from iron.


rr 




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