NP about the name. Just keeping you informed..)

The Ontap version was/is 5.3.6R2. Not sure about the checksum code, how do I tell? Not sure about mapping phases either, software (NetBackup 3.4) is new and I don't know enough about it yet to figure out how to watch detailed progress. But we've had this problem with the old BudTool software too.

First, I think you want Ontap 6.0 or later... Steve Fong optimized code paths that I think you especially will really notice in the newer releases.

Second, think you are also encountering the "downhill dump stream" performance issue.

Basically, the way that the BSD dump stream format works, we need to: 1) Figure out what to put on tape (no data is written out, but we do a lot of work) 2) Write the directories on tape (data goes to tape, but we need to do work on the data as it is written out, so MB/s is increasing but not at our peak) 3) Write the data out to tape (and here, we just read like crazy and write it all out to media)

So, in general, if you've got a 20 GB/hr dump, it means that the data phase (#3) is actually running faster than 20 GB/hr to compensate for the slower earlier stages.

I call it downhill dump stream performance because we start slowly but end up barrelling down the hill with no brakes. Sort of like my parents' old Hyundai Excel... ;)

A third thing to check would be to determine if you have File History enabled on NetBackup. If you do, you might try disabling it for one backup -- to see if it improves your performance. If it does, you could talk to your SE for tips on backing up with File History.

Regardless, I think you'd definitely benefit from 6.0 for dump performance, not to mention the other benefits.

Stephen Manley DAM and NDMP Saturn Owner

Stephen Manley wrote:

...

...

Stephen,

Actually it was me that had the problem with ndmpcopy....

Problem: File system was fragmented due to manner in which addition of disks was done. We would add 1 or 2 at a time over the last 2 years. It got to the point where backups were kicked off but it would be 3+ hours before it would write to tape.

ndmpcopy: When I attempted to use ndmpcopy to split this volume up I got the same write delay and a transfer rate of 1gb/hr. Yes, that's ONE GB per HOUR. So, 156 hours later........ Not a chance.

Hmmm... What version of Ontap were you using?

Specifically, was it pre-5.3.4? Was it pre-6.0?

Second, I'm guessing you had the checksum code enabled?

Third, I assume the "time before writing" was Pass I and II of dump -- mapping phases?

...

A NetApp SE was onsite to witness this and had no idea why it was doing this. Finally settled on rsync. Do you have any idea why it would do this?

I may have a theory, depending on your answers to the questions above.

Sorry I confused you with Jessica. I'd make an excuse about your names starting with the same letter, but I should know better. After all, I expect people to keep all million Stephen/Steven/Steves running around NetApp straight. :)

Sorry, Stephen Manley DAM and NDMP Stephen

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Jeff Kennedy Unix Administrator AMCC jlkennedy@amcc.com