Fw: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM

Fw: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM

[Andrew Morton]

Begin forwarded message:

Date: Fri, 10 Feb 2006 10:19:45 -0800
From: bugme-daemon@bugzilla.kernel.org
To: bugme-new@lists.osdl.org
Subject: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM


http://bugzilla.kernel.org/show_bug.cgi?id=6052

           Summary: Megaraid file corruption and performance degradation on
                    x86_64 with 8G RAM
    Kernel Version: 2.6.15-1.2005_FC4smp
            Status: NEW
          Severity: normal
             Owner: andmike@us.ibm.com
         Submitter: bloch@verdurin.com


Most recent kernel where this bug did not occur:
Distribution: 
Fedora Core 4

Hardware Environment: 

Tyan S2882
2 x Opteron 252
8G RAM
LSI MegaRAID SATA 150-4

Software Environment:

Problem Description:

A RAID1 mirror was setup using the MegaRAID card and 2 x 250 GB drives.
After only a day or so of use, there was severe filesystem corruption (using
ext3) and the user complained that even before the corruption it was incredibly
slow (the mirror is used to house $HOME).

We have other machines here with only 4G RAM using the same card and setup. 
Performance there is fine and there's been no filesystem corruption.

In one case I removed the drives from the card and connected them to the SATA
ports on the motherboard, using software RAID.  That machine is working fine.

In the other case I have tried using a Fedora test kernel, equivalent to
2.6.16-rc2, which has the latest version of the MegaRAID driver (2.20.4.7).
I was unable to recover the filesystem on the original partition when running
fsck using the new kernel.  However, at least on this occasion fsck kept running
(for two days...) instead of crashing.

When running mkfs on the hardware RAID1 mirror, performance still seems to be
very slow.

Hence it appears there is a specific problem with the LSI megaraid driver on
x86_64 machines with more than 4G RAM.

Steps to reproduce:

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Re: Fw: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM

[Gorazd Golob]

Switching off the directio in megaraid's setup to cacheio should help.
It's controller's (32bit) problem not drivers.


On Fri, 2006-02-10 at 11:26 -0800, Andrew Morton wrote:
> 
> Begin forwarded message:
> 
> Date: Fri, 10 Feb 2006 10:19:45 -0800
> From: bugme-daemon@bugzilla.kernel.org
> To: bugme-new@lists.osdl.org
> Subject: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM
> 
> 
> http://bugzilla.kernel.org/show_bug.cgi?id=6052
> 
>            Summary: Megaraid file corruption and performance degradation on
>                     x86_64 with 8G RAM
>     Kernel Version: 2.6.15-1.2005_FC4smp
>             Status: NEW
>           Severity: normal
>              Owner: andmike@us.ibm.com
>          Submitter: bloch@verdurin.com
> 
> 
> Most recent kernel where this bug did not occur:
> Distribution: 
> Fedora Core 4
> 
> Hardware Environment: 
> 
> Tyan S2882
> 2 x Opteron 252
> 8G RAM
> LSI MegaRAID SATA 150-4
> 
> Software Environment:
> 
> Problem Description:
> 
> A RAID1 mirror was setup using the MegaRAID card and 2 x 250 GB drives.
> After only a day or so of use, there was severe filesystem corruption (using
> ext3) and the user complained that even before the corruption it was incredibly
> slow (the mirror is used to house $HOME).
> 
> We have other machines here with only 4G RAM using the same card and setup. 
> Performance there is fine and there's been no filesystem corruption.
> 
> In one case I removed the drives from the card and connected them to the SATA
> ports on the motherboard, using software RAID.  That machine is working fine.
> 
> In the other case I have tried using a Fedora test kernel, equivalent to
> 2.6.16-rc2, which has the latest version of the MegaRAID driver (2.20.4.7).
> I was unable to recover the filesystem on the original partition when running
> fsck using the new kernel.  However, at least on this occasion fsck kept running
> (for two days...) instead of crashing.
> 
> When running mkfs on the hardware RAID1 mirror, performance still seems to be
> very slow.
> 
> Hence it appears there is a specific problem with the LSI megaraid driver on
> x86_64 machines with more than 4G RAM.
> 
> Steps to reproduce:
> 
> ------- You are receiving this mail because: -------
> You are on the CC list for the bug, or are watching someone who is.
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Re: Fw: [Bugme-new] [Bug 6052] New: Megaraid file corruption and performance degradation on x86_64 with 8G RAM

[Andi Kleen]

On Fri, Feb 10, 2006 at 11:26:40AM -0800, Andrew Morton wrote:
> 
> 
> Begin forwarded message:

Hmm, could be the merging issue too? Does megaraid do anything
funny with sg lists? Does iommu=nomerge help?

If yes apply

ftp://ftp.firstfloor.org/pub/ak/x86_64/quilt/patches/gart-dma-merge

and report back.

-Andi