On Tue, Dec 3, 2013 at 2:51 PM, Janos SUTO <[email protected]> wrote: > > On 2013-12-03 17:21, Jeff Larsen wrote: >> >> >> I agree that lacking highly available NFS is unfortunate, however the >> nature of a mail archive is well suited to network storage. So failure >> should be handled gracefully. > > > well, I'm not against NFS (or iscsi for the matter) at all. > > > >> I did a simple test on this. I turned off autofs, unmounting >> /var/piler/store (see note below) and then sent a message that would >> get archived. >> >> mail.log from piler shows: >> Dec 3 09:48:27 mailbackup piler[713]: connection from 192.168.1.75 >> Dec 3 09:48:27 mailbackup piler[713]: >> 40000000529dfd5500926a6c00458043c02d: mkdir >> /var/piler/store/00/529/c0/2d: error=No such file or directory >> Dec 3 09:48:27 mailbackup piler[713]: >> 40000000529dfd5500926a6c00458043c02d: cannot open: >> /var/piler/store/00/529/c0/2d/40000000529dfd5500926a6c00458043c02d.m >> Dec 3 09:48:27 mailbackup piler[713]: >> 40000000529dfd5500926a6c00458043c02d: error storing message: >> 40000000529dfd5500926a6c00458043c02d.m >> Dec 3 09:48:27 mailbackup piler[713]: >> 40000000529dfd5500926a6c00458043c02d: [email protected], size=663, >> attachments=0, reference=, message-id=<[email protected]>, >> retention=0, delay=0.00, delays=0.00/0.00/0.00/0.00/0.00/0.00 >> >> And "postqueue -p" on my mail server shows: >> -Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient------- >> 9165F18151 665 Tue Dec 3 09:48:27 [email protected] >> (host mailbackup.XXX.com[192.168.1.98] said: 451 >> 40000000529dfd5500926a6c00458043c02d <[email protected]> (in >> reply to end of DATA command)) >> [email protected] >> >> -- 1 Kbytes in 1 Request. > > > this is what I expected > > >> >> After restoring the NFS mount, the queued message was eventually >> delivered. >> >> So it appears that the situation is handled gracefully without any >> need to stop piler. > > > good news, thanks for the test. Btw. where do you keep the SQL data, and > the sphinx data? And just for curiosity, how big is your NFS share offered > for piler to store emails? > > > >> One possibly important element in my configuration is that >> /var/piler/store is a symlink to the autofs mounted location. Thus >> when the NFS mount is not there, it is impossible to write to that >> location. If /var/piler/store were a real directory and you directly >> mounted the NFS storage on that point, piler might simply create a new >> file structure on the unused mount point which would get hidden the >> next time the NFS storage is mounted. I did not test this scenario but >> I thought it was worth mentioning in case somebody reads this in the >> future and also chooses to use network storage. I do all my NFS mounts >> this way to prevent "phantom" writes when NFS is down. > > > you have a point, that's why I suggested to make /var/piler/store owned > by root, then piler can't create such a "phantom" directories while NFS > is down. Anyway I'll test it. > > > Janos >
My NFS share is on a 1 TB NAS with about 600GB free. We have a dedicated mysql server in a different virtual machine with it's own storage. I have assumed that the mysql database for piler is mostly metadata and will not be as large as the file store. Maybe I'm wrong. Jeff
