I have done some testing on restore times and have concluded that a
Microsoft Windows box can create between 50-60,000 files per hour. No
faster. So I would conclude that your restore time is optimum. Based
on my experience, obviously. If others have more up-to-date information
about file create speeds, please share. But I am confident that you
have done what you can do on this particular restore.
For grins, create a very large file and backup and restore that file to
see what you get. What I have found for small numbers of large files,
backup time will equal restore time.
Kelly J. Lipp
VP Manufacturing & CTO
STORServer, Inc.
485-B Elkton Drive
Colorado Springs, CO 80907
719-266-8777
lipp AT storserver DOT com
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
James Choate
Sent: Wednesday, May 23, 2007 9:43 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Restore Times
The disk on the client is an UltraSCSI 320 mirrored. The file
characteritics of the client are 50,000 + files. Smaller files, but not
a lot.
The client isn't doing anything, just sitting idle waiting for the
restore.
To be honest, we're not sure what to expect as far as how long it takes
to back up the clients. We haven't been paying attention. We have been
meeting our backup windows, so it hasn't been a concern.
Now management has been pressed to provide feedback with RTO/RPO. So we
have been trying to determine how long it would take to restore some of
our nodes. We have never ever gone thru a true full restore of nodes in
our environment, so we don't have a good feel for it.
The data is backing up to a disk storage pool. We have a 1TB disk
storage pool. It is composed of 2015 F20 disk (Older Shark).
The network is gigabit on the AIX side. But the transfer speeds don't
seem to indicate we are sending data at gigabit speeds.
Thanks for your input.
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Allen S. Rout
Sent: Wednesday, May 23, 2007 9:27 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Restore Times
>> On Wed, 23 May 2007 06:17:30 -0600, James Choate
<jchoate AT CHOOSES1 DOT COM> said:
> Does anyone have any general information that they have collected on
> restore time?
General timing information is nearly useless; not really. Some of the
questions I'll ask below will amplify that. :)
> Were trying to do a restore, and but we're not sure what to expect,
> and we don't have anything to compare it to.
> We are currently restoring 8.17GB to a Windows 2003 server.
> The client is running on IBM x345 hardware.
> The TSM server is a p660 with 2GB memory and 4-HBAs (2 for disk and
> 2 for tape) AIX 5305. I have 14 LTO2 tape drives.
Well, this part is clearly Really Darn Fast. ;)
> The TSM server is TSM 5.4.
> When I backup an 8GB Windows client to the TSM server, it takes 18
minutes.
> When I restore from the disk storage pool, it takes 43 minutes.
> When I restore from the tape storage pool it takes 60 minutes.
What's the disk tech of the client? It seems to be writing 3MB/s: is
that what you get there normally? Is anything else happening on the
accepting client?
Is the restore a few big files, or many little files? Often, for the
small-file case, file system overhead can swamp any throughput desires.
The tape being substantially slower than the disk is reasonable: not so
many disk techs can stream writes as fast as a tape can stream reads. :)
That's actually pretty good backhitch impact, I hadn't thought LTO so
deft.
When you back up it's to a disk-based landing pad, right? (be it DISK or
FILE devclass) What's the disk underneath that? You're only backing up
at ~8M/s: That feels like 100Mb to me, not Gb. Are you sure you're
getting good throughput at the network level?
So, examples that won't help:
I have a p630, with a bunch of SSA disk underneath it, and I usually get
30MB/s backup for a single stream, and can usually restore it from disk
at the recieving boxes' disk-write bottleneck speed.
- Allen S. Rout
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