[plug] Backups

[Marc Wiriadisastra]

I never thought I would answer questions I never asked thats a mint reply.

Thanks heaps for that James thats just clarified a hell of a lot of 
questions that I never thought to ask or even thought about.

Marc

James Devenish wrote:

>In message <4105F77C.80305 at smlintl.com.au>
>on Tue, Jul 27, 2004 at 02:34:36PM +0800, Marc Wiriadisastra wrote:
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>
>>If I wanted to do [backups] to a DVD drive at a pre-determined time
>>obviously I would use a cron job with a DVD but would it be in a
>>script or just entered into the crontab?
>>    
>>
>
>This really need only depend on your administrative tendencies and the
>complexity of the task. Generally, it would be better to make a nice
>script in a nice file of its own, and simply invoke that file from a
>cron job (rather than entering everything on one line in the crontab).
>This also means that you can edit, backup, and modify your script
>independently of cron (i.e. you can test the backup or do an unscheduled
>backup easily).
>
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>
>>Also, would I use dd or some other method for [backups]?
>>    
>>
>
>(I think this is somewhat of a frequently-asked question, so there will
>be further information in the list archives and via Google.) This
>question about dd can be considered in the general case (i.e. not linked
>to DVDs), in which you'd have to ask yourself whether `dd` will produce
>a self-consistent backup. If the disk partition is in use for writing
>(e.g. databases, log files), then this is unlikely. But depending on the
>filesystem and nature of your files, it *might* still be acceptable, for
>*your* purposes, to use dd (even if a bit of `fsck`ing is necessary).
>But if you need to be careful, you'll have to take down your daemons,
>sync, take a filesystem snapshot, then do a backup using the snapshot.
>This sort of thing is mentioned in the list archives. This is in a sense
>a "grey area" and people do whatever is gives the best tradeoff between
>practicality and recoverability. Something like `dump` is generally
>better, because you can restore files on a arbitrary basis onto
>arbitrary partitions (whereas `dd` limits you to restoring an entire
>filesystem onto an identical partition). There are various suggestions
>and examples in the list archives.
>
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>>it has to all be bash based
>>    
>>
>
>No worries -- this will not limit what you can achieve, except to say
>that you won't be able use GUI apps. It's pretty rare for anyone to use
>GUI apps within cron anyway. Note that there may be two "phases" for
>your backup process: one to generate a backup stream or "image" for your
>DVD, and another phase to burn the DVD. Both of these can be done
>without GUIs.
>
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>>can't be GUI because [it's] a server and we don't have X on it.
>>    
>>
>
>Just as a point of clarification: you don't necessarily "have to have X
>installed" on a server just to use X11 programmes. Since X11 is
>inherently based on a client-server model, you can use your own
>/workstation/ to interact with your server's X11 programmes -- you don't
>need to have a display or keyboard attached to your server. You /will/,
>however, need to install a set of X11 software libraries on your server.
>But at least you don't have to install an "X11 server" on your server --
>you just use your workstation as the X11 server.
>
>
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>
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