Jeremy:

I suspect that the delay is in the scan phase of the NDMP backup, which determines which files need to be sent to netBackup for the differential. If you could see how much throughput is going through the gig/e link during the differential versus the full, I think you’d confirm that the actual movement of data from the filers to NetBackup is not the problem.    If you have a large number of files in the volumes, that would certainly allude to this being the problem.

I don’t think this is a netBackup issue, it’s NDMP.

Glenn from Voyant

From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Page, Jeremy
Sent: Tuesday, June 19, 2007 1:19 PM
To: toasters@mathworks.com
Subject: NDMP tuning on a 270c

We are backing up a 270c nightly with Netbackup via NDMP to a dual drive LTO3 machine (only one drive is used for to backup the filer). There are 2.25 TB on one head and 1.1TB on the other. For a full backup it takes about 10 hours to write to tape, which I don't think is too bad (larger volumes hit 31200 KB/sec reported by Netbackup), but the differentials take 5 hours to run,even though the delta on our data is very small.

 I suspect this is more of a Netbackup issue then a filer based one but wanted to throw it out there incase there was something I should look at on the host side. This is over a normal gigE switched network connection with the default settings on the filer, network-wise. We are not using virtual interfaces, both heads have a single 1 gig connection to the LAN. Any suggestions or inventive flames are welcome.

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