On Thu, Sep 30, 2010 at 12:37 PM, Grigori Solonovitch <
Grigori.Solonovitch AT ahliunited DOT com> wrote:

> 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).
>
>
as for 2), because of the XIV block allocation algorithm, this is
unlikely...

1) would be a good hint, that's what we started looking at when we first
detected that TSM was not performing as good as we thought it should. All
links are performing optimally.


I agree that an XIV should be at least comparable to a DS8100, but for now,
we're nowhere even close to the figures you mention. Do note that the DS8000
uses the SDD driver (I assume) and XIV is limited to AIX MPIO.

I am curious as to which verion of TSM you are running, including the exact
patch level.


--
Met vriendelijke groeten,

Remco Post, PLCS