Backups with 9-STABLE -- Options?

[Adam Strohl]

On 6/10/2012 3:08, Karl Denninger wrote:
> With SU+J as the default filesystem, what options actually WORK now?
>
> 1. Dump "L" will NOT -- it doesn't hang any more but now just bitches
> and refuses to run.  I suppose that beats a hang....

Heh, yeah that is improved from what it did before ;D

> 2. Dump without "L" and take your chances?  What risks am I running by
> doing this on a running system?

Depends on what is running and how it does file writes.  For example SQL 
DB storage engines are unlikely to do well (ie; the restore will be 
corrupted if there are changes during the process).  Something like 
CouchDB though which is "always consistent on disk" probably wouldn't care.

Past specific applications (or user activity) the inherent risk is 
unpredictable usefulness of your backups.  Since you're doing backups as 
a safeguard (and are very likely your last hope if things really go 
wrong) you don't want to find out that a key piece corrupted or missing 
entirely due to files moving around during the dump when you end up 
needing it.

> 3.  Other?
>
> Dump has been the canonical means of backing up... forever.  And it
> still is claimed to be the canonical means in the documentation.
>
> So what options do we have now that actually work -- is there now a new
> "canonical" backup method that is recommended?

My solution is to turn off journals for any build.   Dump is a great 
tool (especially when scripted) and is very efficient.

And as neat as journals are, backups using dump with snapshots is way 
more valuable and important in my book.

My .02.

-- 
Adam Strohl
http://www.ateamsystems.com/