Backup Central

I'm researching the advantages of using backup software that supports NDMP vs traditional backup methods (agents). I understand it allows backups/restores of heterogeneous filers. With this I won't need to map a drive drive on Windows/UNIX servers and then backup. So a benefit is less administrative tasks. Also, if the backup device is attached to a filer backing up from the filer to the device is quicker because data doesn't have to go through the backup client first. I'm interested in understanding performance benefits when other types of configurations are in play. For example, what if I'm doing a disk to disk backup. Is there really a performance improvement (network & server) with NDMP vs. mounting to the Windows/UNIX server first and then backing up to another disk? Also, I'm guessing, another benefit is full filer backup/restore is a lot easier with NDMP when there are multiple file systems on the filer.



Your input is appreciated.

The biggest benefit to NDMP is the ability to do backup to a local device. But oddly enough, that's not how most people use it.

When doing remote backups (without a local tape drive), the big advantages I can think are:

1. NDMP should be prioritized lower than NFS requests. Back up via NFS and you look like any other user and have the same priority. Therefore NDMP should have a lower impact on performance -- should.

2. It's the supported way.

3. It should handle Windows & Unix permissions just fine, especially if you have cross-mounted filesystems.

Hi,



For example, what if I'm doing a disk to disk backup. Is there really a performance improvement (network & server) with NDMP vs. mounting to the Windows/UNIX server first and then backing up to another disk?



We're in a similar situation of doing NDMP backup to disk over the network. Supposedly the advantage is that when you do NDMP the NAS (source) knows which files have changed since the last dump level (0 to 9) so the source just streams these files to the target backup NDMP filer, which can be a bunch of disk storage or NDMP capable tape (robot) device.

If you're doing the same thing with something like rsync over NFS/CIFS the backup server would have to stat or checksum each file to determine what files to backup during an incremental. If you've got millions of files this can take a while to figure out which files to backup.

HTH,
Sabuj Pattanayek