zRAM broken on Raring?

sudodus nio.wiklund at gmail.com
Sat Sep 28 16:23:30 UTC 2013


Hi John,

Yes, let us hope the bug will be fixed soon, and it will be back-ported :-)

Can you run your application without zRAM? You can switch it off in a
simple way (and have it ready for reactivation) like this with crontab.
Edit the crontab with

sudo crontab -e

$ sudo crontab -l |tail -n3
# m h  dom mon dow   command
@reboot              /sbin/swapoff /dev/zram*
@reboot              /sbin/rmmod zram

Best regards
Nio

On 28/09/13 18:10, John Hupp wrote:
> Hi, Nio.
>
> That is what puzzled me about Phill's statement that before Saucy,
> zram "was there just not used."
>
> Your confirmation that it is not used in your up-to-date Raring
> install sent me looking for a package that depends on zram-config.  I
> did a Dependencies search in Synaptic and found out that my installed
> ltsp-client package Recommends zram-config.
>
> The nicest solution scenarios would be that zram is fixed in time for
> the Saucy release (there is hope?) and that it is almost
> simultaneously backported to Raring (there is hope?).
>
> But in the meantime I suppose I'll need to talk to the LTSP folks
> about what might be done if neither of the above happens quickly.
>
> --John
>
> On 9/28/2013 4:04 AM, Nio Wiklund wrote:
>> Hi John,
>>
>> I checked in an up to date (update + dist-upgrade) Lubuntu Raring i386
>> standard desktop installation. I find no zRAM block devices, no
>> zram-config, and nothing else, that indicates that zram should be
>> activated. The kernel is 3.8.0.31 #46 according to uname.
>>
>> guru at pae4pm:~$ uname -a
>> Linux pae4pm 3.8.0-31-generic #46-Ubuntu SMP Tue Sep 10 19:56:49 UTC
>> 2013 i686 i686 i686 GNU/Linux
>>
>> I think your zRAM 'came along as a dependency for something'. Maybe you
>> have installed some ppa or other special repository to get new kernels
>> or other new packages. What version is the kernel in your system?
>>
>> Best regards
>> Nio
>>
>> On 2013-09-28 01:06, John Hupp wrote:
>>> The news/announcements concerning Saucy tend to say something "new in
>>> Saucy ... zRAM."
>>>
>>> But zram-config is installed in my Raring i386 standard desktop
>>> installation, and I didn't install it unless it came along as a
>>> dependency for something.
>>>
>>> On 9/27/2013 6:29 PM, Nio Wiklund wrote:
>>>> Sorry, I overlooked that John is running Raring. I didn't think
>>>> zRAM was
>>>> used in Raring, but of course, John can install and run it. I'm
>>>> glad you
>>>> corrected that mistake by me.
>>>>
>>>> Best regards
>>>> Nio
>>>>
>>>> On 2013-09-28 00:08, Phill Whiteside wrote:
>>>>> hi Nio,
>>>>>
>>>>> he is running Raring. The bug we see in Saucy on 1227202 is totally
>>>>> un-related to the sudo parted -l issue.
>>>>>
>>>>> Getting the race issue sorted out on un-mounting the zram areas is
>>>>> what
>>>>> the bug fix is. With all the tests I've done, the
>>>>>
>>>>>    Error: /dev/zram0: unrecognised disk label
>>>>>
>>>>> Error: /dev/zram1: unrecognised disk label
>>>>>
>>>>> Has remained until I used the 3.12rc kernel. We will go battle that
>>>>> issue on Monday to see if we can find the fix. Also do
>>>>> read https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1215379
>>>>> as we
>>>>> may be barking up the wrong tree with zram, and should be using
>>>>> zswap.
>>>>>
>>>>> Joe cannot tell us which is better to use, just that zswap was in the
>>>>> 3.11.2 upstream kernel which has been imported into the latest
>>>>> 3.11.0-9.16 kernel.
>>>>>
>>>>> It was Unit193 who pointed that issue out, and whilst getting the
>>>>> race
>>>>> crash sorted out, it appears that zswap is the updated system.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Phill.
>>>>>
>>>>>
>>>>> On 27 September 2013 22:54, Nio Wiklund <nio.wiklund at gmail.com
>>>>> <mailto:nio.wiklund at gmail.com>> wrote:
>>>>>
>>>>>       On 2013-09-27 23:28, John Hupp wrote:
>>>>>       > On Raring, output from 'sudo parted -l' includes:
>>>>>       >
>>>>>       >     Error: /dev/zram0: unrecognised disk label
>>>>>       >
>>>>>       > And syslog shows a slew of errors:
>>>>>       >
>>>>>       >     Lubuntu kernel: Buffer I/O error on device zram0, logical
>>>>>       block 128247
>>>>>       >
>>>>>       > Syslog also indicates that half of memory was given to
>>>>> zram to
>>>>>       form its
>>>>>       > block device.
>>>>>       >
>>>>>       > Does this mean that half of memory is dedicated to
>>>>> something that
>>>>>       isn't
>>>>>       > working?  And perhaps that machines will hang when swap is
>>>>> needed?
>>>>>       >
>>>>>       > I arrive at this line of questioning because I was testing an
>>>>> LTSP
>>>>>       > client using a Lubuntu LTSP server configured with 1 GB,
>>>>> and when
>>>>>       I drop
>>>>>       > the client memory configuration to 256 MB, the *server* has
>>>>> hung on
>>>>>       > several occasions when I was starting or stopping Firefox
>>>>> on the
>>>>>       client
>>>>>       > (though in one case this coincided with the startup of a
>>>>> SpiderOak
>>>>>       > backup operation).   I didn't think of the Magic SysRq
>>>>> keys at
>>>>> the
>>>>>       time,
>>>>>       > and nothing else was responding, so I did hard shutdowns.
>>>>>       >
>>>>>       > I saw a post from Phill Whiteside recently concerning a
>>>>> rush of
>>>>>       activity
>>>>>       > re a zram bug, but it seemed to be directed at Saucy.
>>>>>       >
>>>>>       > Are there solutions/workarounds?
>>>>>       >
>>>>>       You find a lot of details reading the comments about this bug.
>>>>>
>>>>>       https://bugs.launchpad.net/bugs/1227202
>>>>>
>>>>>       There is a kernel in the pipeline, that we think will solve
>>>>> most
>>>>> if not
>>>>>       all of the problems. Until we get the kernel that can cooperate
>>>>> with
>>>>>       zRAM, you can switch it off either manually or with crontab
>>>>> like
>>>>> this:
>>>>>
>>>>>       guru at Lubuntu-Saucy-b2:~$ sudo crontab -l |tail -n3
>>>>>       # m h  dom mon dow   command
>>>>>       @reboot              /sbin/swapoff /dev/zram*
>>>>>       @reboot              /sbin/rmmod zram
>>>>>
>>>>>       Best regards
>>>>>       Nio
>>>>>
>>>>>       --
>>>>>       Lubuntu-users mailing list
>>>>>       Lubuntu-users at lists.ubuntu.com
>>>>> <mailto:Lubuntu-users at lists.ubuntu.com>
>>>>>       Modify settings or unsubscribe at:
>>>>>       https://lists.ubuntu.com/mailman/listinfo/lubuntu-users
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> -- 
>>>>> https://wiki.ubuntu.com/phillw
>




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