support quality (Re: dump | restore fails: unknown tape headertype 1853384566)

[Peter Schuller]

> The issue with backing up a database live comes in when the filesystem 
> where the database and transaction log files are DIFFERS.  You can get 
> into a pathological case in that instance.
> 
> If the transaction log and database itself are both on the same 
> snapshotted entity (that is, the snapshot is pulled at the same instant 
> in time for both) what you get BETTER be restorable or your database's 
> transaction log facility doesn't really do what it promises to do!

Absolutely. Doing things like snapshot based backups of databases
assumes you know what you're doing since it is not something which is
documented as an official procedure in your typical database
administrator guide.

Personally, while I would use such schemes, I would always use a plain
fully supported regular dump as a fallback position. I would only rely
on snapshot based processes to do fancy stuff (such as near-realtime
hot standby with zfs snaps + serialized incrementals).

-- 
/ Peter Schuller

PGP userID: 0xE9758B7D or 'Peter Schuller <peter.schuller at infidyne.com>'
Key retrieval: Send an E-Mail to getpgpkey at scode.org
E-Mail: peter.schuller at infidyne.com Web: http://www.scode.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 196 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-fs/attachments/20090326/30c95fbe/attachment.pgp