> I'm currently testing TSM 5.5.4 on AIX 5.3 with an IBM XIV box.
>
> When I use dd or other tools to copy data off the disk to tape (LTO4), we
> get quite a good performance, 100 MB/s or better. Even when backing up data
> on the XIV via shared memory directly to tape, we're quite happy, we can
> read the data at over 100 MB/s for one backup job, and for over 200 MB/s for
> two jobs. But, when TSM uses the XIV for DISK volumes, we're not in a happy
> place, backing up data from one XIV to TSM with diskpool on another XIV, we
> get about 55 MB/s per backup job, best case. Both XIV boxes are otherwise
> completely idle. When migrating data of the diskpool to tape, it's the same,
> no matter what we do, we don't even get close to the LTO4 native
> performance, about 70 MB/s is the best I've seen, and usually it's less. The
> TSM server is at that time only running the migration, nothing else.
>
> The stragest thing we notice is that TSM seems to completely pause every so
> often, no disk i/o, no tape i/o no cpu utilization, nothing for about one
> second, and the it goes again. When I let two migration processes run, this
> is less obvious, because one process continues while the other one pauses.
>
> We've opened a hardware call with IBM to find out if there are any settings
> on the hdisks or HBAs that we need to change, and even though we did get
> some hints, and some performance improvement out of that, we fell that TSM
> should be able to do a lot better.
>
> Does anyone else have experience with XIV as a diskpool? and if so, what
> sort of performance do you see?
I do not have XIV, but I am using DS8100 with FATA disks 1TB 7200 RPM.
I am using AIX multipath access (4 paths) via 2-ports adapter and SAN
switches(4Gb/s each port). I have defined primary and copy storage polls for
device class FILE (JFS2 file systems under AIX). Formatting volume speed is
210MB/s for single volume. It can reach 400MB/s and more for a few processes.
As far as I know, SATA disks 1TB or 2TB 7200 RPM are used in XIV.
So you should have at least the same speed as for DS8100 (XIV is much newer!).
I think you need to check for problems with:
1) host connections;
2) or for fragmentation in raw logical volumes for device class DISK (for
example, all volumes were formatted in parallel, not one by one).
Grigori G. Solonovitch
Senior Technical Architect
Information Technology Ahli United Bank Kuwait http://www.ahliunited.com.kw
Phone: (+965) 2231-2274 Mobile: (+965) 99798073 E-Mail: Grigori.Solonovitch
AT ahliunited DOT com
Please consider the environment before printing this Email
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Lloyd Dieter
Sent: Thursday, September 30, 2010 12:20 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] [adsm] TSM and XIV
I'm betting the pauses are the XIV destaging data from cache to physical disk.
Not a big fan of using heavily cached disk LUNs for disk/file storage pools....
On Wed, 29 Sep 2010 13:47:47 +0200
Remco Post <r.post AT PLCS DOT NL> wrote:
> Hi all,
>
> I'm currently testing TSM 5.5.4 on AIX 5.3 with an IBM XIV box.
>
> When I use dd or other tools to copy data off the disk to tape (LTO4), we
> get quite a good performance, 100 MB/s or better. Even when backing up data
> on the XIV via shared memory directly to tape, we're quite happy, we can
> read the data at over 100 MB/s for one backup job, and for over 200 MB/s for
> two jobs. But, when TSM uses the XIV for DISK volumes, we're not in a happy
> place, backing up data from one XIV to TSM with diskpool on another XIV, we
> get about 55 MB/s per backup job, best case. Both XIV boxes are otherwise
> completely idle. When migrating data of the diskpool to tape, it's the same,
> no matter what we do, we don't even get close to the LTO4 native
> performance, about 70 MB/s is the best I've seen, and usually it's less. The
> TSM server is at that time only running the migration, nothing else.
>
> The stragest thing we notice is that TSM seems to completely pause every so
> often, no disk i/o, no tape i/o no cpu utilization, nothing for about one
> second, and the it goes again. When I let two migration processes run, this
> is less obvious, because one process continues while the other one pauses.
>
> We've opened a hardware call with IBM to find out if there are any settings
> on the hdisks or HBAs that we need to change, and even though we did get
> some hints, and some performance improvement out of that, we fell that TSM
> should be able to do a lot better.
>
> Does anyone else have experience with XIV as a diskpool? and if so, what
> sort of performance do you see?
>
> --
> Met vriendelijke groeten,
>
> Remco Post, PLCS
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