IDS Forum

RE: RE: Esoteric Disk Issues

Posted By: Norma Jean Sebastian
Date: Wednesday, 1 April 2009, at 10:44 a.m.

In Response To: RE: RE: Esoteric Disk Issues (Norma Jean Sebastian)

Hi Mike,
Me again...
My old unix admin (he's younger than me, but from my last
job...therefore 'old' :-)) anyway, my old unix admin said the following
about the Sun "quick i/o" software I spoke of:
---------------
It is part of the Veritas Storage Foundation for DB2 Enterprise product,
and the exact "option" is Concurrent I/O (cio) on Veritas File System
(VxFS). With Solaris 10, you can also mention that ZFS could be an
option. It's supposed to be 25% faster than running UFS file system. I
am very interested in testing DB2 performance on ZFS and comparing to
VxFS with CIO enabled. There are some big money savings to be had if
ZFS is comparable in performance.
-------------

Hopefully that is helpful to you even though it's what we had to do when
we (at old job) went from Informix/raw/solaris9(or10) to
DB2/cooked/solaris10. We were initially told that we should not have to
purchase extra software to run DB2/cooked/solaris10, but we found out
the hard way when it was a dog.

As you see from my old admin, he is interested in ZFS, but your original
post said it's not suggested for databases?...
If you'd like to discuss this off-forum, I can loop my old admin in...
can we contact you at your yahoo addr? (jmmagie at yahoo)
Thanks,
NJ

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
MIKE MAGIE
Sent: Tuesday, March 31, 2009 2:31 PM
To: ids@iiug.org
Subject: Re: RE: Esoteric Disk Issues [15385]

Can you elaborate on this NJ? From what I understood if we had a UFS
mounted
file system for example, and when the file system was mounted we used
the
"forcedirectio" option, we would bypass the file system's buffer cache,
closer
mimicking raw disk i/o behavior.

MM

-----Original Message-----
From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
MIKE MAGIE
Sent: Tuesday, March 31, 2009 10:18 AM
To: ids@iiug.org
Subject: Esoteric Disk Issues [15379]

Informix v10.00.UC8
Solaris 10

We are migrating from Sun 8 to Sun 10 and having issues with disk. We
initially used ~1000 two gig "luns" via zfs that were links to devices
or
pools within our HP SAN. With this config, booting our Unix box took ~16
hours
- no typo. We are now looking at other options. These are our options:

1) Use giant ZFS luns with Informix chunk offsets, instead of a lot of
smaller
luns.

2) Use SVM (Sun Volume Manager) with raw devices. We understand that SVM
is
being phased out though and support may be discontinued.

3) Raw UFS

4) Cooked UFS

5) Cooked ZFS

How much slower is cooked than raw - really? I know that Sun now has
direct
i/o mount options and that Informix 11 has config parameters that allow
kaio
to be used with cooked files. Would we die from performance lags if we
were on
cooked files (direct i/o mounted) using aio vps while we moved to
Informix 11?
I have heard that ZFS is not suggested for databases and I am cool with
avoiding it. We are a quasi DW environment with no OLTP use. Ideas?

MM

Messages In This Thread

• Esoteric Disk Issues
  MIKE MAGIE -- Tuesday, 31 March 2009, at 11:18 a.m.
  • Re: Esoteric Disk Issues
    rroussey@comcast.net -- Tuesday, 31 March 2009, at 1:30 p.m.
  • RE: Esoteric Disk Issues
    Norma Jean Sebastian -- Tuesday, 31 March 2009, at 1:39 p.m.
    • Re: RE: Esoteric Disk Issues
      MIKE MAGIE -- Tuesday, 31 March 2009, at 3:31 p.m.
      • RE: RE: Esoteric Disk Issues
        Norma Jean Sebastian -- Wednesday, 1 April 2009, at 10:16 a.m.
        • RE: RE: Esoteric Disk Issues
          Norma Jean Sebastian -- Wednesday, 1 April 2009, at 10:44 a.m.
  • Re: Esoteric Disk Issues
    Obnoxio The Clown -- Thursday, 2 April 2009, at 11:12 a.m.
    • Re: Esoteric Disk Issues
      Art Kagel -- Thursday, 2 April 2009, at 3:39 p.m.
      • Re: Esoteric Disk Issues
        MIKE MAGIE -- Friday, 3 April 2009, at 11:36 a.m.
        • RE: Esoteric Disk Issues
          Norma Jean Sebastian -- Friday, 3 April 2009, at 3:07 p.m.
          • RE: Esoteric Disk Issues
            Norma Jean Sebastian -- Friday, 3 April 2009, at 4:05 p.m.
            • Re: Esoteric Disk Issues
              Art Kagel -- Friday, 3 April 2009, at 4:28 p.m.
          • Re: Esoteric Disk Issues
            Art Kagel -- Friday, 3 April 2009, at 4:21 p.m.

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