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

[Tom Evans]

On Thu, 2009-03-26 at 14:45 +0000, Jake Scott wrote:
..
> Absolutely.  You really must use a tool that interacts with the database 
> to perform the backup.  Most commercial DBs have hooks that allow the 
> backup routines to call out to custom snapshot facilities.  One would 
> usually request a backup through the database, which would then freeze IO 
> to its data files and maybe log files, deal with flushing caches etc and 
> then call your snapshot routine.  I'm not aware that MySQL and Postgres do 
> though so the best you can do is a dump.
> 
> 
> Jake
> 

Just to add, mysql has a utility (mysqlhotcopy) to allow you to directly
copy MyISAM databases with a guarentee of consistency (thus avoiding the
conversion from MyISAM data -> SQL, and no need to reimport when
recovering). It isn't exactly online though, any writes will be blocked
until the hotcopy finishes.

Still, it is only MyISAM, and not much call for that these days..


Cheers

Tom