zRAM broken on Raring?
Phill Whiteside
PhillW at Ubuntu.com
Sat Sep 28 19:20:17 UTC 2013
Hi Leszek,
at this point in 13.10 I'm already thinking ahead to 14.04 :) Asking Julien
to investigate the merits as we will be using the 3.12 kernel in 14.04
makes sense to me :)
I've run the 3.12rc2 for a week on my system, before reverting to the
current 'test' 3.11 kernel with the zram chase fixed, and it's looking darn
good!
Regards,
Phill.
On 28 September 2013 19:51, Leszek Lesner <leszek.lesner at web.de> wrote:
> Am 28.09.2013 18:27, schrieb Phill Whiteside:
> > Hi John,
> >
> > just to add to the fun, unit193 found this....
> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1215379 So, I don't
> > know if we should be using zram or zswap now! It needs looking into by
> > someone with more skilled than me (shouldn't be too hard to find one of
> > those!). Joe from the kernel team simply said that is for the flavours to
> > decide what they use, they just make the kernel :D I've asked Julien to
> > have a look into the matter. The chase that zram was experiencing in the
> > 3.11 kernels has a fix, the other issues are separate bugs and it seems
> > like they have been around for several cycles. It's amazing what
> skeletons
> > come out of the cupboard when someone rattles it hard!
> >
>
> ZSwap is fairly new and not tested yet. zram however is widely tested
> and it was stable (I have been using it on my phone from kernel 2.6.32
> on and later on my laptop in the 3.x cycles) until 3.10.6. So I guess we
> should stick with zram for this release and then later test other
> solutions aswell. Besides zswap there is also zcache btw. we even might
> combine zcache and zram/zswap if we want but that all needs to be tested
> first and currently either zswap nor zcache are really tested as they
> are fairly new.
>
> >
> >
> > On 28 September 2013 17:10, John Hupp <lubuntu at prpcompany.com> 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<
> 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<
> 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<
> Lubuntu-users at lists.ubuntu.com>
> >>>>>>>
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> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> --
> >>>>>> https://wiki.ubuntu.com/phillw
> >>>>>>
> >>>>>
> >>
> >
> >
> >
> >
>
>
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