Making disk IO place nicely in a guest (VirtualBox)

[Mike Tancsa]

On 8/7/2014 5:27 PM, Adam Vande More wrote:
>
> The error messages shown are classic swap on ZFS errors which is
> inherently unstable especially under high IO loads.

Hi Adam,
	I am still running into the guest crashing, or throwing disk errors 
even when the Hypervisor is not touching swap.  I brought the Hypervisor 
OS upto date (r269715) and only ran the one guest instance

# pstat -T
191/514621 files
0M/16384M swap space

I tried with a RELENG7 instance, trying to extract a large tar file and 
it crashed as the parent's disk was too busy

ad0: FAILURE - device detached
g_vfs_done():ad0s1d[WRITE(offset=175350517766, length=2048)]error=6
/var: got error 6 while accessing filesystem
panic: softdep_deallocate_dependencies: unrecovered I/O error
cpuid = 0

On the RELENG_10 guest instance (r269271), I still get the odd

ahcich0: Timeout on slot 15 port 0
ahcich0: is 00000000 cs 00000000 ss 0fff8000 rs 0fff8000 tfd 50 serr 
00000000 cmd 1000dd17
(ada0:ahcich0:0:0:0): WRITE_FPDMA_QUEUED. ACB: 61 00 e8 7f 20 40 02 00 
00 01 00 00
(ada0:ahcich0:0:0:0): CAM status: Command timeout
(ada0:ahcich0:0:0:0): Retrying command

When doing the same test with Linux as the hypervisor, there are no 
errors in the guests.



	---Mike


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Mike Tancsa, tel +1 519 651 3400
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