[Dovecot] Experience with ALTStorage on NFS mount

Hi,

we are thinking about storing older mails (eg. safed before 6 months) to an alternative storage mounted via NFS from an external storage box.

Some technical details

• the storage will be connected via 1 gbit ethernet. Access will be allowed from different dovecot servers, but only to divided directories for each dovecot.
• storage has the option to use RAID 5 or 6. Max. amount of Disks are 15.
• the index files and the primary storage are just divided in two different directories and are stored local on SAS disks with RAID 10
• current mail_location config is: mdbox:/home/vmail/%d/%n:INDEX=/home/dovecotindex/%d/%n
• future mail_location config shoudl look like: mdbox:/home/vmail/%d/%n:INDEX=/home/dovecotindex/%d/%n:ALT=/home/extstorage/vmail/%d/%n

My question is, if someone of you have already experience in such a setup with NFS? And are there some tuning tips for NFS? We have not many experience with NFS right now.

Or perhaps is there some better solution?

Many thanks and regards Urban