NDMP differenctial backup questions, If a file changes

If a file changes,

Does NDMP backup to whole file or only the changed blocks.


Specifically for a TSM-Celerra NDMP configuration, If a full backup
was performed on a file system. And then only 1Kb of the a file
system changed, will the entire file be rebacked up or only the 1 Kb
file.

Does NDMP somehow take advantage of savvol differentials?


Thanks

Tom

NDMP spec says no. NDMP is just a protocol, any special vodoo is done
by the vendor or not at all. For the backup to be block based the
backup software would have to be block aware. So you can answer the
question very easily if you use NBU, Legato, BakBone, Workstation
Solutions, etc. No.

Now, for example, if you have NetApp and BakBone you can use BakBone
to manage and control Snapmirror to tape. This is a block level data
transfer to tape but is definitely vendor specific. The backup
software merely facilitates robotics and tape changing.

~F

On 8 Dec 2003 14:17:45 -0800, (Tom Woods) wrote:

If a file changes,

Does NDMP backup to whole file or only the changed blocks.


Specifically for a TSM-Celerra NDMP configuration, If a full backup
was performed on a file system. And then only 1Kb of the a file
system changed, will the entire file be rebacked up or only the 1 Kb
file.

Does NDMP somehow take advantage of savvol differentials?


Thanks

Tom