[Gluster-users] Email storage backend for Sendmail, Maildir, and Courier-imap

[Keith Freedman]

we ran into this problem.
it seems related to timestamps being off by microseconds.
when someone would check their email on one machine, then hit another 
whose time was off by even microseconds, it would think all the 
messages are suddenly new or different from ones it's checked.

my guess is this problem doesn't exist in 2.0 because of the way it 
manages timestamps on files in HA.

However, I can't tell you for sure, since we switched to dovecot 
which tracks messages by message id instead of timestamps and is also 
much more efficient.

hope that helps.

At 08:28 PM 1/21/2009, Cory Meyer wrote:
>I'm working on a project to use GlusterFS as the backend for email 
>storage to replace the current NFS implementation.  The goal is to 
>configure GlusterFS w/AFR to replicate the files across all 3 
>storage nodes.   Each storage node will also act a an email server 
>configured behind a load balancer running Sendmail, Maildrop, and 
>Courier-Imap.
>
>Main issue so far seems to be related with Courier-Imap in that when 
>moving messages between IMAP folders some messages are duplicated 
>with the io-threads enabled on the client side.  Issue looks to be 
>on the Courier-IMAP side though I haven't seen this with NFS and the 
>duplicate messages within the Maildir have unique file names.
>
>Any other simular experiences with email services backended with GlusterFS?
>
>Node test hardware x 3:
>Quad core Xeon 2Ghz w/ 4x7200rpm SATA drives.
>Raid5 across all 4 drives. (Raid0 will also be tested if additional 
>speed is necessary)
>8Gb Ram
>
>Network:  Currently 100Mbit though production will be 1Gbit.
>
>Os: Debian Etch  (2.6.18-6-686-bigmem)
>GlusterFS:  1.3.12
>Fuse: 2.7.3glfs10
>Courier-imap 4.1.1.20060828-5
>
>Partition Layout:
>sda1 --> Os (ext3)
>sda2 --> Swap
>sda5 --> glusterfs_data (ext3)
>
>GlusterFS patched Fuse kernel module, util, and libraries have been 
>installed on each of my 3 storage nodes.
>
>Here is the basics of my Gluster configuration.
>Server:  Brick --> TCP
>Client:  Bricks -->  AFR --> io-thread --> write-behind --> io-cache 
>--> read-ahead
>
>Follow the Pastebin URL for my raw config file:
><http://glusterfs.pastebin.com/f7814657c>http://glusterfs.pastebin.com/f7814657c
>
>Any suggestions?
>
>-- Cory
>
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