Lockups when running vm's with 768MB of memory

[karl anliot]

version tested: ubiquity 2.10.20 on 12.04.1 daily build.
$md5sum precise-desktop-amd64.iso
64cae667e6fde29ea86043ede5e79493 precise-desktop-amd64.iso

Reproducing:
setup a new KVM machine with 768 MB of ram. (because users were reporting crashes with 768)

*after booting, select try Ubuntu
* start the installer, but not anything else.
* select "something else"
since the disk has no parition table, click to create a "new partition table
create an 888 megabyte swap at the end of the disk
create a 7701 M swap at the beginning of the disk.
Ubiquity crashes when clicking to the next screen.

you'll notice that the syslog has a: OSError: [Errno 12] Cannot allocate memory.

To fix this bug, ubiquity should not be installing on PC's with too little RAM, especially when crashes are so consistent.
Ubiquity should CLEARLY warn about crashes on low-ram machines.

here's the syslog and other stuff:
x@ubu:~$ pastebinit debug
http://paste.ubuntu.com/1158548/
x@ubu:~$ pastebinit partman
http://paste.ubuntu.com/1158549/
x@ubu:~$ pastebinit syslog
http://paste.ubuntu.com/1158550/
x@ubu:~$ pastebinit version
http://paste.ubuntu.com/1158551/
x@ubu:~$ cat version
ubiquity 2.10.20

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1039405

[Colin Watson (cjwatson)]

I use 768MB for all my installer test VMs, and it's not that long since I bumped that up from 512MB; so there is something else wrong here, and I don't think simply giving up and pre-emptively refusing to install with 768MB is the right answer here.

[karl anliot (kanliot)]

I'm only doing your testing on 512MB and 768MB for you. If you have
any additional tests you'd like me to run I can accomodate you.

On Tue, Aug 21, 2012 at 11:14 AM, Colin Watson <email address hidden> wrote:
> I use 768MB for all my installer test VMs, and it's not that long since
> I bumped that up from 512MB; so there is something else wrong here, and
> I don't think simply giving up and pre-emptively refusing to install
> with 768MB is the right answer here.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1039405
>
> Title:
> Lockups when running vm's with 768MB of memory
>
> Status in “ubiquity” package in Ubuntu:
> New
> Status in “ubiquity” source package in Precise:
> New
>
> Bug description:
> version tested: ubiquity 2.10.20 on 12.04.1 daily build.
> $md5sum precise-desktop-amd64.iso
> 64cae667e6fde29ea86043ede5e79493 precise-desktop-amd64.iso
>
> Reproducing:
> setup a new KVM machine with 768 MB of ram. (because users were reporting crashes with 768)
>
> *after booting, select try Ubuntu
> * start the installer, but not anything else.
> * select "something else"
> since the disk has no parition table, click to create a "new partition table
> create an 888 megabyte swap at the end of the disk
> create a 7701 M swap at the beginning of the disk.
> Ubiquity crashes when clicking to the next screen.
>
> you'll notice that the syslog has a: OSError: [Errno 12] Cannot
> allocate memory.
>
> To fix this bug, ubiquity should not be installing on PC's with too little RAM, especially when crashes are so consistent.
> Ubiquity should CLEARLY warn about crashes on low-ram machines.
>
> here's the syslog and other stuff:
> x@ubu:~$ pastebinit debug
> http://paste.ubuntu.com/1158548/
> x@ubu:~$ pastebinit partman
> http://paste.ubuntu.com/1158549/
> x@ubu:~$ pastebinit syslog
> http://paste.ubuntu.com/1158550/
> x@ubu:~$ pastebinit version
> http://paste.ubuntu.com/1158551/
> x@ubu:~$ cat version
> ubiquity 2.10.20
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1039405/+subscriptions

[karl anliot (kanliot)]

I've noticed that if ubiquity is using 2 swap files, then this bug will never occur.

It's also a known behavior of the swapoff function. See this comment:

http://unix.stackexchange.com/questions/45441/what-command-can-be-used-to-force-release-everything-in-swap-partition-back-to-m#comment62823_45443

[karl anliot (kanliot)]

You might ask why you can't reproduce the behavior when running in a debugger:

quoting Hugh Dickins of the kernel mailing list:
So, if the whole system is under memory pressure, kswapd will
be keeping the RSS of all tasks low, and they won't reach their
limits; whereas if the system is not under memory pressure,
tasks will easily approach their limits and so fail.

[Simon Quigley (tsimonq2)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. It would help us a lot if you could test it on a currently supported Ubuntu version. If you test it and it is still an issue, kindly upload the updated logs by running only once:
apport-collect 1039405

and any other logs that are relevant for this particular issue.

[Steve Langasek (vorlon)]

The Precise Pangolin has reached end of life, so this bug will not be fixed for that release

[Launchpad Janitor (janitor)]

[Expired for ubiquity (Ubuntu) because there has been no activity for 60 days.]