very large mailboxes backup, long retention period deleted also

[Andre Felipe Machado]

Hello,
Thanks for your suggestions.
Reading list archives, many alerted against NFS for cyrus imap.
Someone listed the fwrite syscall as the source of problems with NFS.

I found some old bug reports
https://bugzilla.redhat.com/show_bug.cgi?id=90159
http://forums.codeguru.com/showthread.php?322677-Problems-with-fwrite-and-NFS
but browsing http://git.cyrusimap.org/cyrus-imapd/ a little, it seems that
recent 2.4.x versions uses fwrite only for db operations.

Is this assumption correct?
Are there another syscalls in cyrus that cause trouble with NFS 3 or 4?

If so, then, as we use metadata partition at separated high-speed LUN  on fs and
kernel tuned for small files[1,2,3],  it could be possible to use NFS only for
data partition.

Had anyone tried this approach on production?

What are the recent cyrus 2.4.x versions experiences over NFS?


Regards.
Andre Felipe Machado
[1]
http://www.techforce.com.br/news/linux_blog/lvm_raid_xfs_ext3_tuning_for_small_files_parallel_i_o_on_debian
[2]
http://www.techforce.com.br/news/linux_blog/debian_linux_kernel_tuning_low_latency_small_files
[3] http://www.techforce.com.br/news/linux_blog/xenserver_reduzir_latencia_i_o





On 19/Mar/2013 09:50 Eric Luyten <Eric.Luyten at vub.ac.be> wrote ..

> > Maybe, if cyrus becomes compatible with NFS, then HSM solutions like
> > http://www.openarchive.net could help.
> 
> 
> Andre,
> 
> While, in general, participants in this forum still are pretty reluctant
> putting their Cyrus mailstores on NFS storage, there has been at least
> one architect/administrator of a very large Cyrus configuration pretty
> happy using NetApp filers and NFS as their underlying storage structure.
> When using intelligent storage (does not have to be NFS, sub-LUN tiering
> in block access methods (iSCSI, FC) will also do the job) you will be
> pushing the tiering issue down to your storage level, which may be (part
> of) a solution to your problem.
> 
> Kind regards,
> Eric Luyten, Computing Centre VUB/ULB.