Horton

Thread

  1. Adaptec/LSI/?? RAID

    Stacy White <harsh@computer.org> — 2005-06-02T03:42:58Z

    We're in the process of buying another Opteron server to run Postgres, and
based on the suggestions in this list I've asked our IT director to get an
LSI MegaRaid controller rather than one of the Adaptecs.

But when we tried to place our order, our vendor (Penguin Computing) advised
us:

"we find LSI does not work well with 4GB of RAM. Our engineering find that
LSI card could cause system crashes. One of our customer ... has found that
Adaptec cards works well on PostGres SQL -- they're using it as a preforce
server with xfs and post-gress."

Any comments?  Suggestions for other RAID controllers?

  2. Re: Adaptec/LSI/?? RAID

    Sven Willenberger <sven@dmv.com> — 2005-06-02T04:35:51Z

    
Stacy White presumably uttered the following on 06/01/05 23:42:
> We're in the process of buying another Opteron server to run Postgres, and
> based on the suggestions in this list I've asked our IT director to get an
> LSI MegaRaid controller rather than one of the Adaptecs.
> 
> But when we tried to place our order, our vendor (Penguin Computing) advised
> us:
> 
> "we find LSI does not work well with 4GB of RAM. Our engineering find that
> LSI card could cause system crashes. One of our customer ... has found that
> Adaptec cards works well on PostGres SQL -- they're using it as a preforce
> server with xfs and post-gress."
> 
> Any comments?  Suggestions for other RAID controllers?
> 
> 
> ---------------------------(end of broadcast)---------------------------

We use the LSI MegaRaid 320-2x with the battery-backed cache on a dual 
opteron system that uses 8G of RAM. OS is FreeBSD amd64 (5.4) and runs 
without hesitation. Database currently over 100GB and it performs 
admirably. So chalk one anecdotal item towards the LSI column. To be 
fair I have not tried an Adaptec card with this setup so I cannot 
comment positively or negatively on that card. As a side note, we did 
have issues with this setup with Linux (2.6 kernel - 64bit) and XFS file 
system (we generally use FreeBSD but I wanted to try other 64bit OSes 
before committing). Whether the linux issues were due to the LSI, 
memory, Tyan mobo, or something else was never determined -- FreeBSD ran 
it and did so without flinching so our choice was easy.

HTH

Sven

  3. Re: Adaptec/LSI/?? RAID

    William Yu <wyu@talisys.com> — 2005-06-02T05:00:09Z

    I've used LSI MegaRAIDs successfully in the following systems with both 
Redhat 9 and FC3 64bit.

Arima HDAMA/8GB RAM
Tyan S2850/4GB RAM
Tyan S2881/4GB RAM

I've previously stayed away from Adaptec because we used to run Solaris 
x86 and the driver was somewhat buggy. For Linux and FreeBSD, I'd be 
less worried as open source development of drivers usually lead to 
better testing & bug-fixing.


Stacy White wrote:
> We're in the process of buying another Opteron server to run Postgres, and
> based on the suggestions in this list I've asked our IT director to get an
> LSI MegaRaid controller rather than one of the Adaptecs.
> 
> But when we tried to place our order, our vendor (Penguin Computing) advised
> us:
> 
> "we find LSI does not work well with 4GB of RAM. Our engineering find that
> LSI card could cause system crashes. One of our customer ... has found that
> Adaptec cards works well on PostGres SQL -- they're using it as a preforce
> server with xfs and post-gress."
> 
> Any comments?  Suggestions for other RAID controllers?
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings
>

  4. Re: Adaptec/LSI/?? RAID

    Andrew McMillan <andrew@catalyst.net.nz> — 2005-06-02T09:15:13Z

    On Wed, 2005-06-01 at 20:42 -0700, Stacy White wrote:
> We're in the process of buying another Opteron server to run Postgres, and
> based on the suggestions in this list I've asked our IT director to get an
> LSI MegaRaid controller rather than one of the Adaptecs.
> 
> But when we tried to place our order, our vendor (Penguin Computing) advised
> us:
> 
> "we find LSI does not work well with 4GB of RAM. Our engineering find that
> LSI card could cause system crashes. One of our customer ... has found that
> Adaptec cards works well on PostGres SQL -- they're using it as a preforce
> server with xfs and post-gress."
> 
> Any comments?  Suggestions for other RAID controllers?

Hi,

We're using the Megaraid (Intel branded model) on a dual Opteron system
with 8G RAM very happily.  The motherboard is a RioWorks one, the OS is
Debian "Sarge" AMD64 with kernel 2.6.11.8 and PostgreSQL 7.4.7.

Cheers,
					Andrew.

-------------------------------------------------------------------------
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WEB: http://catalyst.net.nz/            PHYS: Level 2, 150-154 Willis St
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  5. Re: Adaptec/LSI/?? RAID

    Richard Welty <rwelty@averillpark.net> — 2005-06-02T11:50:22Z

    On Wed, 01 Jun 2005 22:00:09 -0700 William Yu <wyu@talisys.com> wrote:
> I've previously stayed away from Adaptec because we used to run Solaris 
> x86 and the driver was somewhat buggy. For Linux and FreeBSD, I'd be 
> less worried as open source development of drivers usually lead to 
> better testing & bug-fixing.

Adaptec is in the doghouse in some corners of the community because they
have behaved badly about releasing documentation on some of their
current RAID controllers to *BSD developers. FreeBSD has a not-quite-free
driver for those latest Adaptecs. OpenBSD wants nothing to do with them.

richard
-- 
Richard Welty                                         rwelty@averillpark.net
Averill Park Networking
    Java, PHP, PostgreSQL, Unix, Linux, IP Network Engineering, Security
      "Well, if you're not going to expect unexpected flames,
         what's the point of going anywhere?" -- Truckle the Uncivil

  6. Re: Adaptec/LSI/?? RAID

    J. Andrew Rogers <jrogers@neopolitan.com> — 2005-06-02T17:10:14Z

    I've got a bunch of mission-critical Postgres servers on 
Opterons, all with no less than 4GB RAM,  running Linux + 
XFS, and most with LSI MegaRAID cards. We've never had a 
single system crash or failure on our postgres servers, 
and some of them are well-used and with uptimes in excess 
of a year.

It may be anecdotal, but LSI MegaRAID cards generally seem 
to work pretty well with Linux.  The only problem I've 
ever seen was a BIOS problem between the LSI and the 
motherboard, which was solved by flashing the BIOS on the 
motherboard with the latest version (it was grossly out of 
date anyway).


J. Andrew Rogers

  7. Re: Adaptec/LSI/?? RAID

    Joshua D. Drake <jd@commandprompt.com> — 2005-06-02T17:42:46Z

    > It may be anecdotal, but LSI MegaRAID cards generally seem to work 
> pretty well with Linux.  The only problem I've ever seen was a BIOS 
> problem between the LSI and the motherboard, which was solved by 
> flashing the BIOS on the motherboard with the latest version (it was 
> grossly out of date anyway).

At Command Prompt we have also had some great success with the LSI 
cards. The only thing we didn't like is the obscure way you have to 
configure RAID 10.

Sincerely,

Joshua D. Drake

> 
> 
> J. Andrew Rogers
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 6: Have you searched our list archives?
> 
>               http://archives.postgresql.org


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  8. Re: Adaptec/LSI/?? RAID

    Vick Khera <vivek@khera.org> — 2005-06-02T17:47:49Z

    On Jun 1, 2005, at 11:42 PM, Stacy White wrote:

> "we find LSI does not work well with 4GB of RAM. Our engineering  
> find that
> LSI card could cause system crashes. One of our customer ... has  
> found that
> Adaptec cards works well on PostGres SQL -- they're using it as a  
> preforce
> server with xfs and post-gress."
>
> Any comments?  Suggestions for other RAID controllers?
>

I have twin dual opteron, 4GB RAM, LSI MegaRAID-2X cards with 8 disks  
(2@RAID0 system+pg_xlog, 6@RAID10 data) running FreeBSD 5.4-RELEASE.

Works just perfectly fine under some very heavy insert/update/delete  
load.  Database + indexes hovers at about 50Gb.

I don't use the adaptec controllers because they don't support  
FreeBSD well (and vice versa) and the management tools are not there  
for FreeBSD in a supported fashion like they are for LSI.


Vivek Khera, Ph.D.
+1-301-869-4449 x806

  9. Re: Adaptec/LSI/?? RAID (what about JBOD?)

    mudfoot@rawbw.com — 2005-06-02T21:02:03Z

    I have a similar question about what to choose (either LSI or Adaptec U320), but
plan to use them just for JBOD drivers.  I expect to be using either net or
freebsd.  The system CPU will be Opteron.  My impression is that both the ahd
and mpt drivers (for U320 Adaptec and LSI, respectively) are quite stable, but
not from personal experience.  Like I said, I don't plan to have the cards doing
RAID in hardware.  Should I be pretty safe with either choice of HBA then?

Thanks (and sorry for the semi-hijack).


Quoting Vivek Khera <vivek@khera.org>:

> 
> On Jun 1, 2005, at 11:42 PM, Stacy White wrote:
> 
> > "we find LSI does not work well with 4GB of RAM. Our engineering  
> > find that
> > LSI card could cause system crashes. One of our customer ... has  
> > found that
> > Adaptec cards works well on PostGres SQL -- they're using it as a  
> > preforce
> > server with xfs and post-gress."
> >
> > Any comments?  Suggestions for other RAID controllers?
> >
> 
> I have twin dual opteron, 4GB RAM, LSI MegaRAID-2X cards with 8 disks  
> (2@RAID0 system+pg_xlog, 6@RAID10 data) running FreeBSD 5.4-RELEASE.
> 
> Works just perfectly fine under some very heavy insert/update/delete  
> load.  Database + indexes hovers at about 50Gb.
> 
> I don't use the adaptec controllers because they don't support  
> FreeBSD well (and vice versa) and the management tools are not there  
> for FreeBSD in a supported fashion like they are for LSI.
> 
> 
> Vivek Khera, Ph.D.
> +1-301-869-4449 x806
> 
> 
>

  10. Re: Adaptec/LSI/?? RAID (what about JBOD?)

    Andrew McMillan <andrew@catalyst.net.nz> — 2005-06-02T23:19:28Z

    On Thu, 2005-06-02 at 14:02 -0700, mudfoot@rawbw.com wrote:
> I have a similar question about what to choose (either LSI or Adaptec U320), but
> plan to use them just for JBOD drivers.  I expect to be using either net or
> freebsd.  The system CPU will be Opteron.  My impression is that both the ahd
> and mpt drivers (for U320 Adaptec and LSI, respectively) are quite stable, but
> not from personal experience.  Like I said, I don't plan to have the cards doing
> RAID in hardware.  Should I be pretty safe with either choice of HBA then?

On the machine I mentioned earlier in this thread we use the Megaraid
for JBOD, but the card setup to use the disks that way was somewhat
confusing, requiring us to configure logical drives that in fact matched
the physical ones.  The card still wanted to write that information onto
the disks, reducing the total disk space available by some amount, but
also meaning that we were unable to migrate our system from a previous
non-RAID card cleanly.

Regards,
					Andrew.

-------------------------------------------------------------------------
Andrew @ Catalyst .Net .NZ  Ltd,  PO Box 11-053, Manners St,  Wellington
WEB: http://catalyst.net.nz/            PHYS: Level 2, 150-154 Willis St
DDI: +64(4)803-2201      MOB: +64(272)DEBIAN      OFFICE: +64(4)499-2267
Whereof one cannot speak, thereon one must remain silent. -- Wittgenstein
-------------------------------------------------------------------------

  11. Re: Adaptec/LSI/?? RAID (what about JBOD?)

    mudfoot@rawbw.com — 2005-06-03T00:30:30Z

    Thanks, Andrew.  I expect to choose between HBAs with no RAID functionality or
with the option to completely bypass RAID functionality--meaning that I'll
hopefully avoid the situation that you've described.  I'm mostly curious as to
whether the driver problems described for U320 Adaptec RAID controllers also
apply to the regular SCSI drivers.

Thanks.

Quoting Andrew McMillan <andrew@catalyst.net.nz>:

> On Thu, 2005-06-02 at 14:02 -0700, mudfoot@rawbw.com wrote:
> > I have a similar question about what to choose (either LSI or Adaptec
> U320), but
> > plan to use them just for JBOD drivers.  I expect to be using either net
> or
> > freebsd.  The system CPU will be Opteron.  My impression is that both the
> ahd
> > and mpt drivers (for U320 Adaptec and LSI, respectively) are quite stable,
> but
> > not from personal experience.  Like I said, I don't plan to have the cards
> doing
> > RAID in hardware.  Should I be pretty safe with either choice of HBA
> then?
> 
> On the machine I mentioned earlier in this thread we use the Megaraid
> for JBOD, but the card setup to use the disks that way was somewhat
> confusing, requiring us to configure logical drives that in fact matched
> the physical ones.  The card still wanted to write that information onto
> the disks, reducing the total disk space available by some amount, but
> also meaning that we were unable to migrate our system from a previous
> non-RAID card cleanly.
> 
> Regards,
> 					Andrew.
> 
> -------------------------------------------------------------------------
> Andrew @ Catalyst .Net .NZ  Ltd,  PO Box 11-053, Manners St,  Wellington
> WEB: http://catalyst.net.nz/            PHYS: Level 2, 150-154 Willis St
> DDI: +64(4)803-2201      MOB: +64(272)DEBIAN      OFFICE: +64(4)499-2267
> Whereof one cannot speak, thereon one must remain silent. -- Wittgenstein
> -------------------------------------------------------------------------
> 
>

  12. Query limitations (size, number of UNIONs ...)

    Marc Mamin <m.mamin@gmx.net> — 2005-06-03T06:35:28Z

    Hello,


I've split my data in daily tables to keep them in an acceptable size.

Now I have quite complex queries which may be very long if I need to query a
large number of daily tables.


I've just made a first test wich resulted in a query being 15KB big annd
containing 63 UNION.

The Query plan in PGAdmin is about 100KB big with 800 lines :-)


The performance is not such bad, but I'm wondering if there are some
POSTGRES limitations I should take care of with this strategy.


Thanks,

Marc

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  13. Re: Adaptec/LSI/?? RAID

    Cosimo Streppone <cosimo@streppone.it> — 2005-06-03T07:37:17Z

    Stacy White wrote:

> We're in the process of buying another Opteron server to run Postgres, and
> based on the suggestions in this list I've asked our IT director to get an
> LSI MegaRaid controller rather than one of the Adaptecs.
> 
> But when we tried to place our order, our vendor (Penguin Computing) advised
> "we find LSI does not work well with 4GB of RAM. Our engineering find that
> LSI card could cause system crashes. One of our customer ... has found that
> Adaptec cards works well on PostGres SQL

Probably, your vendor is trying to avoid problems at all, but
"one of our customers" is not a pretty general case, and
"we find LSI does not work well", but is there a documented reason?

Anyway, my personal experience has been with an Acer Altos R701 + S300
external storage unit, equipped with LSI Logic Megaraid U320 aka
AMI Megaraid aka LSI Elite 1600
(honestly, these cards come with zillions of names and subnames, that
I don't know exactly how to call them).

This system was configured in various ways. The final layout is
3 x RAID1 arrays (each of 2 disks) and 1 x RAID10 array (12 disks).
This configuration is only available when you use 2 LSI cards (one
for each S300 scsi bus).

The system behaves pretty well, with a sustained sequential write rate
of 80Mb/s, and more importantly, a quite high load in our environment
of 10 oltp transactions per second, without any problems and
`cat /proc/loadavg` < 1.

I don't like the raid configuration system of LSI, that is
counter-intuitive for raid 10 arrays. It got me 4 hours and
a tech support call to figure out how to do it right.

Also, I think LSI cards don't behave well with particular
raid configurations, like RAID 0 with 4 disks, or RAID 10
with also 4 disks. It seemed that these configurations put
the controller under heavy load, thus behaving unreasonably
worse than, for example, 6-disks-RAID0 or 6-disks-RAID1.
Sorry, I can't be more "scientific" on this.

For Adaptec, I don't have any direct experience.

-- 
Cosimo

  14. Re: Query limitations (size, number of UNIONs ...)

    Stephen Frost <sfrost@snowman.net> — 2005-06-03T13:27:20Z

    * Marc Mamin (m.mamin@gmx.net) wrote:
> I've just made a first test wich resulted in a query being 15KB big annd
> containing 63 UNION.

If the data is distinct from each other or you don't mind duplicate
records you might try using 'union all' instead of 'union'.  Just a
thought.

	Stephen