kernel_task kernel panic with Mountain Lion under pressure

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three more panics

Post by grahamperrin » Sun Jan 20, 2013 6:52 am

In recent weeks, three more panics that probably fit with this topic.

All three incidents involved use of a VirtualBoxVM running Windows 7. If I recall correctly, all had the familiar lines in Console some time before the panic:

kernel[0]: aio_queue_async_request(): too many in flight for proc: 16.
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Cross reference

Post by grahamperrin » Sat Jan 26, 2013 1:36 am

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Three more panics

Post by grahamperrin » Wed Feb 27, 2013 10:36 pm

The two most recent panics of the Mac were with Windows 7, in a VirtualBoxVM with 1 GB memory, whilst Apple Software Update on Windows installed the update to iTunes 11.0.2.

I experimented cautiously with the following changes to file system properties:

2013-02-27.06:26:55 zfs set primarycache=none zhandy
2013-02-27.06:27:28 zfs set compression=off zhandy
2013-02-27.06:30:49 zfs set sync=disabled zhandy

– after which Windows in the VirtualBoxVM completed the routine without a panic of the Mac. I shouldn't treat that success with those properties as conclusive, just for the record.

sync=disabled is too risky for my liking so now:

2013-02-28.02:26:14 zfs set sync=standard zhandy
2013-02-28.02:28:24 zfs set primarycache=metadata zhandy

– and I'll proceed with background runs of two VirtualBoxVMs to see whether a panic occurs.
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Re: kernel_task kernel panic with Mountain Lion under pressu

Post by mk01 » Mon Mar 04, 2013 8:16 am

I don't know of ZEVO, but for instance linux implementation is still with no native ail support, so for example mysql won't even start on ZFS without skip-native-aio parameter.

maybe similar issue with VirtualBox on mac on ZEVO?

Anyhow Parallels is running with no issues and all my images are on ZEVO. To compare, I have even Win7 machine, 64bit, running with 4vcpus and 4gigs ram.
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Update

Post by grahamperrin » Sun Mar 17, 2013 9:28 am

With no recent panics, touch wood:

Code: Select all
macbookpro08-centrim:~ gjp22$ zfs get atime,compression,primarycache zhandy
NAME    PROPERTY      VALUE         SOURCE
zhandy  atime         off           local
zhandy  compression   on            local
zhandy  primarycache  metadata      local


Code: Select all
macbookpro08-centrim:~ gjp22$ zpool history zhandy | grep primarycache
2013-02-27.06:26:55 zfs set primarycache=none zhandy
2013-02-28.02:28:24 zfs set primarycache=metadata zhandy


Touch wood, because I haven't tested the file system with VirtualBox as much as I'd like.

A comprehensive view of all non-default property values for the dataset:

Code: Select all
macbookpro08-centrim:~ gjp22$ zfs get all zhandy | grep -v -e 'default$' -e '-$'
NAME    PROPERTY              VALUE                  SOURCE
zhandy  compression           on                     local
zhandy  atime                 off                    local
zhandy  snapdir               visible                local
zhandy  primarycache          metadata               local
zhandy  sync                  standard               local


(Side note: thanks to BjoKa for some inspiring commands in other topics.)

zpool history for the pool shows that atime has never been on for any of its datasets.

I'm now updating to VirtualBox 4.2.10 (2013-03-15), I aim to test aggressively.

Thought

Is there anything about a VirtualBoxVM that might require atime=on ?

Glancing at part of virtualbox.org • View topic - Discuss All about VDIs (2008), I guess not:

bmwiedemann wrote:… I now did actual benchmarking to compare atime/noatime performance, but found no significant improvement. 2-4 seconds difference for 17 minutes of compiling a 2.6.27 kernel might well be caused by random noise. Of course, there are more IO-intensive tasks. …
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Re: Update

Post by mk01 » Mon Mar 18, 2013 4:45 pm

grahamperrin wrote:Thought

Is there anything about a VirtualBoxVM that might require atime=on ?

Glancing at part of virtualbox.org • View topic - Discuss All about VDIs (2008), I guess not:

bmwiedemann wrote:… I now did actual benchmarking to compare atime/noatime performance, but found no significant improvement. 2-4 seconds difference for 17 minutes of compiling a 2.6.27 kernel might well be caused by random noise. Of course, there are more IO-intensive tasks. …


I assume the benchmark was running inside the VM while changing that filesystem atime on/off, operating thousand of files during kernel compile. It can't have significant impact changing it on host filesystem (where the VM FS is one file).
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Comparison

Post by grahamperrin » Thu Mar 21, 2013 2:37 am

For reference only, another topic that may be comparable:


I'm now testing without the following:

  • LaCieScsiType00.kext
  • SATSMARTDriver.kext
  • SATSMARTLib.plugin
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Update

Post by grahamperrin » Sun Mar 24, 2013 2:52 pm

Without the three things listed in my previous post: so far, no kernel panics, and I have pushed VirtualBoxVMs fairly hard for both Windows 7 and Ubuntu 12.10.

Recalling that some time ago I had repeated difficulty with a particular Microsoft installation on Windows 7 (repeated kernel panics of the Mac) … taking a hint from viewtopic.php?p=773#p773 … I:

  1. reduced the machine for Windows to 1 GB memory
  2. removed/uninstalled Remote Server Administration Tools for Windows 7
  3. restarted Windows
  4. reinstalled Remote Server Administration Tools for Windows 7

– and as much as possible during those periods, I did not have the VirtualBoxVM in front.

No panics.

Postscript

viewtopic.php?p=3698#p3698 (keyword: cats) reminds me that probably in 2012-12 I set aside or discarded the short cable that I most often used with the USB 2 device that features in this topic. I doubt that the short cable alone was a cause of panics in this topic, but also it's worth noting:

  • that shorter cable was often at the (weighted) tail of a D-Link extension around two arms' length.

Then a few days ago I discovered – with a different extension cable – that sometimes the Mac simply does not find the drive. So now I avoid using extension cables with this device.

Today, with a supposedly good short cable alone (no extension), one reportedly improper eject (red alert from the OS) after I ejected, then disconnected and reconnected the mini plug of the cable. No panic, but again I wonder whether there's a cable issue.

If I don't write again under this topic, please assume that:

  • kernel panics with this hard disk drive – StoreJet Transcend – no longer occur.
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cookied kernel panics with com.getgreenbytes.filesystem.zfs

Post by grahamperrin » Fri Mar 29, 2013 4:01 pm

An incident this morning around 08:00.

In the .panic file at http://www.wuala.com/grahamperrin/public/2013/03/29/b/ the
BSD process name corresponding to current thread:

  • is not kernel_task
  • is cookied

– but I reckon that it belongs under this kernel_task kernel panic topic. There was a comparable panic in January. In both incidents the running apps included Safari and a VirtualBoxVM.

This morning: one VirtualBoxVM running Windows 7 with 1536 MB memory, another VirtualBoxVM running Ubuntu with 1024 MB memory. If I recall correctly, the panic occurred shortly after a restart of Ubuntu. Amongst the messages that were logged in the five minutes before the panic:

Code: Select all
2013-03-29 07:55:04.000 kernel[0]: aio_queue_async_request(): too many in flight for proc: 16.
2013-03-29 07:57:41.000 kernel[0]: aio_queue_async_request(): too many in flight for proc: 16.


StoreJet Transcend TS640GSJ25M2 (similar to the 25M2 range, but a different capacity).

Until yesterday, my habit was to connect the StoreJet to the MacBookPro5,2. This morning's incident was different:


Also unusual this morning: whilst each VirtualBoxVM ran, I throttled its processor from 100% to 40%.

Of all my topics, this is the only one where I'd like either a resolution, or an authoritative explanation for the kernel panics.

Postscript

For the record, I don't use the USB Y-cable originally supplied with the drive. It was discarded or set aside after unexpected disconnections made me suspect an issue with the cable.

From the web page for the 25M2:

StoreJet external hard drives are powered directly via your computer’s USB port. However, some computers may not be able to supply enough power by using just one USB port. If your StoreJet drive does not function properly, connect both ends of the USB Y-cable to two USB ports on your computer to ensure the StoreJet drive receives sufficient power. Please also avoid using a USB HUB when connecting the StoreJet drive to your computer to avoid the possibility of insufficient power supply.


I use a standard cable (not Y-), connected to just one port. The hub is powered. I believe that the drive functions properly with the given power.
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Re: kernel_task kernel panic with Mountain Lion under pressu

Post by grahamperrin » Mon Jun 03, 2013 2:01 am

BSD process name corresponding to current thread: kernel_task


I probably haven't seen that since January or February 2013 but yesterday's panic

> BSD process name corresponding to current thread: diskimages-helpe

– makes me suspect that there's room for improvement in ZEVO Community Edition 1.1.1 …

… suspect that I might again encounter a kernel_task kernel panic whilst using a VirtualBoxVM.

I'm not entirely certain that this is a bug in ZEVO. Also, if it is a bug, I find it difficult to make reproducible and so it could be difficult to fix. Still, the impact (however rare) is high and so it's tentatively the third item on my wish list of bugs to be fixed in the next version of ZEVO.
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