[kernel-xen] Kernel Panic

[Steffan Cline]

Steven,



On 4/5/16, 3:22 PM, "kernel-xen on behalf of Steven Haigh" <kernel-xen-bounces at lists.wireless.org.au on behalf of netwiz at crc.id.au> wrote:
>On 6/04/2016 1:11 AM, Steffan Cline wrote:
>> Had an odd issue a couple weeks back where I checked on my server and
>> there was a kernel panic. I didn’t think much of it and restarted. It
>> booted into the default CentOS 6 kernel. Once I realized what happened I
>> rebooted back into the Xen kernel just fine.
>> 
>> This morning I woke to find that the server had been crashing and
>> rebooting for several hours.
>> 
>> I logged in and the cause seems to be the notorious error "module
>> scsi_wait_scan not found” There are no good easy solutions on how to fix
>> this.
>
>This isn't a crash. The error shows because the module doesn't exist.
>I'm not keep on patching the init scripts of EL6 to remove the message
>as that has the potential to cause more problems than to remove a
>cosmetic only error.

Can you please tell me how to patch it? I’ll happily boot back to an older kernel, change it and reboot.


>> Most docs I came across say it was supposed to be removed a while back.
>
>And it has - hence you see the 'error'.

That ‘error’ repeated itself about a dozen times before the computer crashed and rebooted repeatedly. I should have taken a screenshot to be able to document some of the different kernel panics I saw when trying different kernels. One I did see was usb 1-3.3: device descriptor read/8, error -110 on a couple different kernels. The RAM did pass the memory checks if that matters.


>> Suggestions anyone? I only got my system back up by using an older Xen
>> kernel. Hard part is my mail runs in a VM on the system. Such luck.
>
>Which kernel were you using? DomU configuration? Dom0 configuration? Are
>you using PVH? Linux guest? Windows guest? 'Older Xen kernel' in what?
>The DomU? The Dom0?

I was using kernel-xen-4.4.6-2.el6xen.x86_64. I’m only a novice with virtualization but if I have it right, it’s Dom0. 
The host is CentOS 6.7 and I had 2 CentOS 6.7 guests and a Windows Server 2008R2 goes.

The older kernel I reverted to in order to get the system back up is 4.4.4-2.el6xen.x86_64.


>
>As a side note, I'd recommend removing the stock kernels on the Dom0 -
>it will operate quite fine without them.

I’d heard that before too but if it wasn’t for that, I’d wouldn’t have been able to get it back up and check everything first. I’ll probably do that once I figure out how to fix this.
>



Thank you,
Steffan Cline
602-793-0014