[Discuss] Backing up LVM partitions using snapshots

[richard.pieri at gmail.com (Richard Pieri)]

On 12/14/2011 12:34 PM, Bill Bogstad wrote:
> I've been watching the (second?) incarnation of this thread for a
> while now and I think that I see your point.  I wonder if the "TRIM"
> functionality that is being added to filesystems in order to handle
> SSDs could help with this.

I don't think so.  The problem I describe is that once a dump goes 
missing then any differentials against it will have inconsistencies 
between the file data and the file metadata structures.  TRIMming freed 
blocks won't make this go away.  It might make things worse what with 
dangling inode lists pointing to de-allocated SSD blocks.


As an aside, enterprise backup systems like Amanda and Bacula and TSM 
do, indeed, maintain databases of backed up files and what media they 
are on.