Re: [Dovecot] Gluster / DRBD Anyone using either?

2008-02-28 Thread Timo Sirainen

On Feb 28, 2008, at 12:53 PM, Ed W wrote:

Anyone using either Glusterfs or DRBD in their mail setup?  How is  
performance, manageability?  Problems?  Tips?


I tried GlusterFS and found some bugs from it. One of them was at  
least fixed (locking issues with 64bit systems). Also GlusterFS has  
similar caching problems than NFS, so mail_nfs_*=yes with v1.1 makes  
it work correctly when multiple servers are accessing the same  
maiboxes at the same time.




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Re: [Dovecot] Gluster / DRBD Anyone using either?

2008-02-28 Thread Pawel Panek



Anyone using either Glusterfs or DRBD in their mail setup?  How is
performance, manageability?  Problems?  Tips?

Ed W



I tried to use Glusterfs (1.3.7) on mail cluster (qmail + dovecot), but for 
me it was terrifying mistake. The cluster is serving about 1,5k mail 
accounts. It was slow, unreliable and unstable. In bonnie++ tests it has 
nice values, about 65MB/s read and 30MB/s write (storage was ext3 on raid5 
on SATA2 drives on Intel E6750), but random seeks was slow (I think) 80 
seeks/s. This values are for single client (old one), and storage server 
could easily handle 3 simultaneous bonnie tests.
But when it comes to serve many small files it caused big load on cluster 
nodes, especially on older ones (P4 Northwood 3,0) causing poor performance. 
It showed up unstability getting segfaults in io-cache brick or even in 
client brick causing disconnecting the gluster mount.
I was using glusterfs modified fuse module (2.7.2glfs8). With fuse module 
shipped with 2.6.24 kernel I have some filesystem permissions issues causing 
reading wrong permissions of files.

DRBD should be right choice if you only need failover function.
I was using very minimal config and maybe I have misconfigured something.
Pawel 



Re: [Dovecot] Gluster / DRBD Anyone using either?

2008-02-28 Thread Philipp Kolmann

Philipp Kolmann wrote:

Ed W wrote:
 > Anyone using either Glusterfs or DRBD in their mail setup?  How is
 > performance, manageability?  Problems?  Tips?

I have DRBD below IMAP and it works nice for 20 accounts.

A collegue has the student POP3/IMAP Server here with a 2.9 TB DRBD 
slice and dovecot on it with no other services and it works really nicely.


/dev/drbd02.9T  252G  2.5T  10% /users


On the later, we host over 22k users. FYI.
Philipp


Re: [Dovecot] Gluster / DRBD Anyone using either?

2008-02-28 Thread Philipp Kolmann

Ed W wrote:
> Anyone using either Glusterfs or DRBD in their mail setup?  How is
> performance, manageability?  Problems?  Tips?

I have DRBD below IMAP and it works nice for 20 accounts.

A collegue has the student POP3/IMAP Server here with a 2.9 TB DRBD 
slice and dovecot on it with no other services and it works really nicely.


/dev/drbd02.9T  252G  2.5T  10% /users


hth
Philipp