Archive:Backup Infrastructure

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The other half of the raid array for the homedirs in dalek is sitting in brigadier. We do not have any form of backups of homedirs in place, other than a copy from about a year ago.

Same applies to the webserver, although it's raid is in place, the disk has some very bizarre filesystem errors (re: ~kate/qcmweb)

Things to backup

User data

This is stuff we just can't get back/rebuild

LDAP

Currently backed up using '/root/ldap/backup', run from cron on Piper (the LDAP server). The script saves backups to '/export/home/backups/ldap/' and these should be copied elsewhere, for obvious reasons.

Home dirs

RAIDed again but no regular backups as yet.

Mail dirs

Similarly

Web dirs

Raid-Mirrored. Not backed-up.

Databases

Not backed up. We should probably do SQL dumps, rather than dumps of the raw db backened.

Lists Service

Not backed up. No idea how it needs to be done.

Other stuff

System configurations

LCFG proved too much of a beast to handle. Best methods for doing this, suggestions?

Backing up /etc would help in a lot of cases, but isn't a proper solution.

System logs

There's probably some sense in this, if we get haX0rised, but that's probably OTT.

Logs are kept on each system and sent to Piper (see Log_Host) so this should be enough.

The wiki

This could/should be covered by our regular (cough) database backups.

DNS data

This could be covered by the 'System configurations' bit above or be done by taking backups of 'leela:/etc/bind/' specifically.

Xen

It might be good to take some LVM snapshots of the root FSes of our Xen VMs. It's not a real backup but would be a quick way to recover from any problems on the VMs.

The firewall

We could do with some backups of the firewall script.

Solution

Pert had started installing a new machine which contained one 120GB disk in LVM.

This was going to run BackupPC but this does not allow users to restore thier own files and does not seem to play well with rsync. Therefore I've been testing a new solution, using rsync to create hard-link-based incremental backups. The script I've been writing is currently in /root/ on piper and so far this has only been tested on the home directories.

Architecture

Backups will be pushed from the various servers (file, web, etc.) to backup.t using rsync, some scripts and cron. Rsync's '--link-dest' argument will be used to create hard-link-based incremental backups on the LVMed space in backup.t.

As it would be tricky to monitor the backups on each of the servers using the backup service, (file, web, etc.) monitoring will be done by a script on backup.t. It should mail daily reports to a specific person (WV me (pert)) who will notice and fix things if the mails stop. These mails should contain disk usage info from backup.t and warn about missed backups. This script will probably also be responsible for removing backups as they get old.

Backups of home directories and mail will be shared out to the shell server(s) using NFS so users can restore their own files.

Here's an example of the directory structure used on backup.t:

/export/
/export/home
/export/home/2006-02-23
/export/home/2006-02-23/newusers
...
/export/home/2006-02-24
/export/home/2006-02-24/newusers
...
/export/mail/2006-02-23
/export/mail/2006-02-23/pert
...
/export/mysql
...
/export/psql
...
...