Tuesday, November 16, 2010

Scheduled downtime this weekend

Hey OCFers,

In order to give OCF mail a much-needed reliability boost, we plan to incrementally replace our current mail infrastructure with a centralized, redundant new system. The current system is scattered and full of single points of failure — as an example, our SpamAssassin server didn't survive last week's power outage, and our mail servers were forced to reject all incoming mail until we were able to build a replacement spam filter on a different machine. Our hope is that this new system will be significantly less volatile and more maintainable.

To that end, we'll be taking OCF mail down this Saturday. We'll be migrating mail storage, outgoing SMTP, IMAP/POP, and webmail to the new mail server. Incoming mail will not be accepted while we're working on the servers, but we'll try to keep read-only access to your old mail online for most of the day. As always, you can follow our progress here and on IRC.

UPDATE (20 November, 12:15PM): It begins! We've taken incoming mail offline and made /var/mail read-only for the mailspool migration.

UPDATE (20 Nov, 2:30PM): We've finished copying data from the old mailstore to the new one and are in the process of switching NFS servers. IMAP/POP access to mail is now down.

UPDATE (20 Nov, 5:30PM): We're having a bit of trouble with the new NFS server; IMAP/POP is still down, and our login servers hung and had to be rebooted a short while ago. tsunami and conquest should be working now, though.

UPDATE (20 Nov, 6:45PM): The NFS server is now up and running, now that we've squashed a pesky NFSv4-related bug (thanks to sluo and dwc for their help!). /var/mail is no longer read-only. Once we finish migrating disk quota information, we'll bring the mail servers back online. Thanks for your patience.

UPDATE (21 Nov, 12:15AM): /var/mail has been fully migrated to the new NFS server, and we've re-enabled the old mail servers. Incoming mail and POP/IMAP still live on the old infrastructure, but now that the NFS server migration is complete we should be able to set up the new infrastructure with minimal downtime.

To be clear, we have not yet migrated SMTP, IMAP/POP, or webmail to the new mail server, but we plan to do so in the near future. Watch this space for updates.