RHEL 6 I/O error messages during booting

RHEL 6 I/O error messages during booting

[Christian May]

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Hi,

I'm new to this community so maybe my question is alreayd answered/solved. 
In that case please let me know how...

I have several IBM blades running RHEL6 and RHEL 6.1 attached via FC 
switch to different FastT storage servers (prefered/non-prefered pathes).
During booting  I've noticed billions of I/O error messages which extend 
the boot process. I found that the scsi_dh_rdac
driver is build into the initramfs, so it should be available when the 
system is recognizing the SCSI LUNs. When taking a look to the messages
I found this statement "kernel: rdac: device handler registered" after the 
SCSI LUNs were recognized?!

Any ideas?

Regards,

Christian
 

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Re: RHEL 6 I/O error messages during booting

[Mike Snitzer]

On Thu, May 05 2011 at  6:58am -0400,
Christian May <christian_may@de.ibm.com> wrote:

> Hi,
> 
> I'm new to this community so maybe my question is alreayd answered/solved. 
> In that case please let me know how...
> 
> I have several IBM blades running RHEL6 and RHEL 6.1 attached via FC 
> switch to different FastT storage servers (prefered/non-prefered pathes).
> During booting  I've noticed billions of I/O error messages which extend 
> the boot process. I found that the scsi_dh_rdac
> driver is build into the initramfs, so it should be available when the 
> system is recognizing the SCSI LUNs. When taking a look to the messages
> I found this statement "kernel: rdac: device handler registered" after the 
> SCSI LUNs were recognized?!
> 
> Any ideas?

The scsi_dh_rdac module is loaded after the FC driver.  This is a known
issue (happens for scsi_dh_emc too).

Mike

Re: RHEL 6 I/O error messages during booting

[Chandra Seetharaman]

Create a new initramds by using the --preload option to mkinitrd.

Exact syntax can be found in section 5.1 of
http://sourceware.org/lvm2/wiki/MultipathUsageGuide

chandra
On Thu, 2011-05-05 at 12:58 +0200, Christian May wrote:
> Hi, 
> 
> I'm new to this community so maybe my question is alreayd
> answered/solved. In that case please let me know how... 
> 
> I have several IBM blades running RHEL6 and RHEL 6.1 attached via FC
> switch to different FastT storage servers (prefered/non-prefered
> pathes). 
> During booting  I've noticed billions of I/O error messages which
> extend the boot process. I found that the scsi_dh_rdac 
> driver is build into the initramfs, so it should be available when the
> system is recognizing the SCSI LUNs. When taking a look to the
> messages 
> I found this statement "kernel: rdac: device handler registered" after
> the SCSI LUNs were recognized?! 
> 
> Any ideas? 
> 
> Regards, 
> 
> Christian 
> 
>  
> 
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel

Re: RHEL 6 I/O error messages during booting

[Malahal Naineni]

Chandra Seetharaman [sekharan@us.ibm.com] wrote:
> Create a new initramds by using the --preload option to mkinitrd.
> 
> Exact syntax can be found in section 5.1 of
> http://sourceware.org/lvm2/wiki/MultipathUsageGuide

I don't that works in RHEL6. It seems to be a known issue in RHEL6.

Thanks, Malahal.

Re: RHEL 6 I/O error messages during booting

[Mike Snitzer]

On Tue, May 10 2011 at  3:40pm -0400,
Malahal Naineni <malahal@us.ibm.com> wrote:

> Chandra Seetharaman [sekharan@us.ibm.com] wrote:
> > Create a new initramds by using the --preload option to mkinitrd.
> > 
> > Exact syntax can be found in section 5.1 of
> > http://sourceware.org/lvm2/wiki/MultipathUsageGuide
> 
> I don't that works in RHEL6. It seems to be a known issue in RHEL6.

A valid workaround should be to pass rdloaddriver=<drivername> on the kernel
commandline, e.g.: rdloaddriver=scsi_dh_emc

RHEL 6 I/O error messages during booting

[Daniel Lang]

Hello,
We are having an issue that appears to be related to fact that the 
scsi_dh_rdac module is loaded after the qla FC driver and  SAN paths 
coming up before rdac can handle them. How can we change the order of 
kernel modules so that the scsi_dh_rdac module is loaded before the FC 
driver?
We are getting long boot times and random crashes due to this issue

Thanks!
Dan

RHEL 6 I/O error messages during booting

[Daniel Lang]

We are having an issue that appears to be related to fact that the 
scsi_dh_rdac module is loaded after the qla FC driver and  SAN paths 
coming up before rdac can handle them. How can we change the order of 
kernel modules so that the scsi_dh_rdac module is loaded before the FC 
driver?
We are getting long boot times and random crashes due to this issue

Re: RHEL 6 I/O error messages during booting

[Mike Snitzer]

On Fri, Oct 28 2011 at  5:13pm -0400,
Daniel Lang <langd@lanl.gov> wrote:

> We are having an issue that appears to be related to fact that the
> scsi_dh_rdac module is loaded after the qla FC driver and  SAN paths
> coming up before rdac can handle them. How can we change the order
> of kernel modules so that the scsi_dh_rdac module is loaded before
> the FC driver?

Add 'rdloaddriver=scsi_dh_rdac' to the kernel commandline to have the
initramfs preload the module (scsi_dh_rdac.ko should already be in the
initramfs).