ADSM-L

Re: Slow restore for large NT client outcome.. appeal to Tivoli Development/Support

2000-09-20 12:54:10
Subject: Re: Slow restore for large NT client outcome.. appeal to Tivoli Development/Support
From: Nicholas Cassimatis/Raleigh/IBM <nickpc AT US.IBM DOT COM>
Date: Wed, 20 Sep 2000 12:52:55 -0400
Jeff,

One thing to show your NT Admins is just how much overhead NTFS has.  The
way I've done this before is to copy a drive, either locally or over the
network.  If you take one of the drives with a lot of small files, can copy
it, the performance will drop as the copy goes on.  The more files you
stick on an NTFS partition, the higher the overhead becomes.  The way the
NTFS allocation tables work, the more files you put in, the more complex
the tables become.

Here's the test I did, in basic form:

On a system with a large drive, net use (NT speak - "Map Network Drive") to
an empty drive on an adjacent machine.
Copy a 20GB directory (from the command line - no NT speak) to this drive.
Measure performance.
Delete data on target system.
Copy entire drive to target.  Measure performance.
Laugh as NT Admins realize how bad the performance gets with the larger
drive.

(If you can't tell from the above, I'm not much of an NT fan)

Nick Cassimatis
nickpc AT us.ibm DOT com

"I'm one cookie away from happy." - Snoopy (Charles Schulz)