Bringing the TiBS backup system under LCFG control

The School is now at the point of having made substantial progress in moving the School's backups to the TiBS backup system. At present however, the system is almost entirely hand configured. Apart from being a highly undesirable feature of a backup system in general, TiBS cannot be considered to be a full DICE service until as much of its configuration as is practical can be brought under LCFG control. This document considers what needs to be done to turn TiBS into a full service. Note that devproj 122 has been created to cover the development of TiBS as a full service.

Aims.

LCFG should be capable of automatically and (as far as possible) fully reproducing the TiBS server configuration on a fresh machine, to aid disaster recovery. LCFG should as far as possible be fully in charge of the TiBS server and client configuration and day to day running and administration. Installation, configuration, use and administration of TiBS should where possible be automated, giving less scope for human error.

Installation.

At present, TiBS (both client and server) is installed from a tarball via a script supplied by Teradactyl. LCFG should reproduce the end result of installing the client files then running the install script. All TiBS configuration variables should be settable from LCFG resources.

Both client and server require a number of additions to their profile to configure xinetd to run the TiBS daemons and tcpwrappers to allow the server to contact these daemons . These entries should be grouped in a header file. Tibs is run via cron and suitable entries to enable this should also be added to the header file.

Configuration

Much of TiBS is configured via a number of text files located in /usr/tibs/state. Most of these (caches.txt, classes.txt, drives.txt, tibs.conf) are suitable and appropriate for bringing under LCFG control.

Others (for example barcodes.txt, clients.txt) should only be changed via the appropriate TiBS commands - though run from the LCFG component rather than directly - and the component will have to be written to allow this. The component will where possible attempt to simplify the sometimes quite wordy TiBS commands by filling in default values from LCFG resources.

There is a large directory tree under /usr/tibs which will need to be put under LCFG control. In some cases this will mean just installing a Teradactyl-supplied file. In other cases it will mean modifying a Teradactyl-supplied file at install time using values from LCFG resources. Other files will be maintained and changed by LCFG from time to time. Others will be maintained by TiBS software which itself will be run by LCFG, either automatically or at the behest of a system administrator.

Individual File System Considerations

AFS
TiBS does the majority of configuration of AFS backups automatically. For example, newly created volumes are added automatically to the list of volumes to be backed up.There is little here that needs further configuration. AFS fileservers need no TiBS software.

Non-AFS Linux
These file systems are added manually via the hostadd command. At the minimum, the TiBS component should have access to resources listing which partitions it is expected to back up and should synchronise this with what it is actually backing up. This list might for instance be generated by the TiBS component from a spanning map which could be populated by the fstab component. The host machines of these filesystems need TiBS software and configuration and are the machines referred to as "!TiBS clients".

Mac/Windows
It's not clear yet what this will involve so it's not possible to say what the component will need to do to support these file systems.

Monitoring

TiBS includes a mechanism for generating customised reports. It should be possible to write a suitable interface to nagios to allow problems and errors to be flagged up. I would envisage that this would form a follow up to the original writing of the component.

See Also

ServicesUnitTiBSConfigFiles - the list of which TiBS config files to manage (or not) with the LCFG component.

-- CraigStrachan - 02, 09 Jun 2009
-- ChrisCooke - 08, 10 Jun 2009.

Topic revision: r6 - 24 Aug 2009 - 11:18:51 - ChrisCooke
 
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