Public bug reported:
About 8 times over this cycle, I have installed various versions of 12.04
server edition on a pathetic old test computer.
In addition to the regular testiing, the purpose is to verify minimum system
specifications.
The issue raised herein first appeared with the i386 server ISO of 2012.04.12.
The issue remains with an up to date system as of 2012.04.21.
The issue does NOT exist with a fresh install from the i386 server ISO of
2012.03.27, which the most recent preceeding ISO I had.
The issue: Under very intensive disk I/O situations, the system can lock
up. Eventually (I think after about 30 seconds, I am actually rarely
standing beside the computer when this occurs) the system does realize
it is frozen and manages to resume. It appears as though the computer
is waiting for some data from the disk, but the disk doesn't think it
has anything to do. I.E. they are out of sync. The appropriate lines
from kern.log will be attached.
The issue does not appear to be with the kernel itself, because it can
be created by starting from the fresh install from the 2012.03.27 ISO
and doing "apt-get update" and "apt-get upgrade" but not "apt-get dist-
upgrade". I do not know which package introduced the issue, which is why
I have not been able to run "ubuntu-bug <packagename>" for this report.
I did list them all before any updates and after, and will post both the
difference file and my edited difference file, where I took my best
guess at editing out ones that I didn;t think would be contain the root
cause.
Note also bug number 978384, which seems similar but not the same.
Regardless, the test kernel page does have the verion i would need to
try.
For testing for this issue I use "sudo update-apt-xapian-index --force",
but I have seen the same issue a few times other other heavy disk usage
conditions.
This issue has been demonstrated with two older style ATA hard drives.
Both drives have been health tested with disk test tools and the system
booted from a freedos ISO.
The enitre start from a fresh install from the 2012.03.37 ISO and test
and sow no issue and then upgrade and test and show issue has been
rpeated several times. This latest test included 8 times running "sudo
update-apt-xapian-index --force" without any problem on a fresh
installation and 9 times running ""sudo update-apt-xapian-index --force"
after only "apt-get update" and "apt-get upgrade" and re-booting, thus
running the same kernel.
It is possible that my CPU is the problem, being below the minimum
server edition specifications (200 Mhz, whereas mininmum spec is 300
Mhz). However, the CPU is largely idle with these tests, as it mostly
waits for disk I/O. (O.K., it also does have some pretty busy periods.)
Attachments will be added over the next hour.
doug@test-smy:~/source-temp$ uname -a
Linux test-smy 3.2.0-23-generic-pae #36-Ubuntu SMP Tue Apr 10 22:19:09 UTC 2012
i686 i686 i386 GNU/Linux
doug@test-smy:~/source-temp$ cat /proc/version
Linux version 3.2.0-23-generic-pae (buildd@palmer) (gcc version 4.6.3
(Ubuntu/Linaro 4.6.3-1ubuntu4) ) #36-Ubuntu SMP Tue Apr 10 22:19:09 UTC 2012
doug@test-smy:~/source-temp$ lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04
** Affects: ubuntu
Importance: Undecided
Status: New
** Tags: precise
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https://bugs.launchpad.net/bugs/986654
Title:
disk I/O race condition after update
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