[ClusterLabs] Antw: Re: Antw: Re: Using different folder for /var/lib/pacemaker and usage of /dev/shm files

Tue May 17 11:57:57 UTC 2016

>>> Nikhil Utane <nikhil.subscribed at gmail.com> schrieb am 17.05.2016 um 11:07 in
Nachricht
<CAGNWmJX-MMzPrSoWqULp1BpgrKmNXR4Vbi7zZB=owAhyLK2=ww at mail.gmail.com>:
> What I would like to understand is how much total shared memory
> (approximately) would Pacemaker need so that accordingly I can define the
> partition size. Currently it is 300 MB in our system. I recently ran into
> insufficient shared memory issue because of improper clean-up. So would
> like to understand how much Pacemaker would need for a 6-node cluster so
> that accordingly I can increase it.
> 
> # df -kh
> tmpfs                   300.0M     27.5M    272.5M   9% /dev/shm

This is a node from a three-node cliuster (SLES11 SP4), with no tuning applied to SHM sizes:
# df /dev/shm
Filesystem     1K-blocks  Used Available Use% Mounted on
tmpfs            2111120 73368   2037752   4% /dev/shm

Regards,
Ulrich


> 
> Thanks
> Nikhil
> 
> On Tue, May 17, 2016 at 12:09 PM, Ulrich Windl <
> Ulrich.Windl at rz.uni-regensburg.de> wrote:
> 
>> Hi!
>>
>> One of the main problems I identified with POSIX shared memory (/dev/shm)
>> in Linux is that changes to the shared memory don't affect the i-node, so
>> you cannot tell from a "ls -rtl" which segments are still active and which
>> are not. You can only see the creation time.
>>
>> Maybe there should be a tool that identifies and cleans up obsolete shared
>> memory.
>> I don't understand the part talking about the size of /dev/shm: It's
>> shared memory. See "kernel.shmmax" and "kernel.shmall" in you sysctl
>> settings (/etc/sysctl.conf).
>>
>> Regards,
>> Ulrich
>>
>> >>> Nikhil Utane <nikhil.subscribed at gmail.com> schrieb am 16.05.2016 um
>> 14:31 in
>> Nachricht
>> <CAGNWmJVSye5PJgkdbFAi5AzO+Qq-j=2fS1c+0rGnqS994vV48w at mail.gmail.com>:
>> > Thanks Ken.
>> >
>> > Could you also respond on the second question?
>> >
>> >>     Also, in /dev/shm I see that it created around 300+ files of around
>> >>     250 MB.
>> >>
>> >>     For e.g.
>> >>     -rw-rw----    1 hacluste hacluste      8232 May  6 13:03
>> >>     qb-cib_rw-response-25035-25038-10-header
>> >>     -rw-rw----    1 hacluste hacluste    540672 May  6 13:03
>> >>     qb-cib_rw-response-25035-25038-10-data
>> >>     -rw-------    1 hacluste hacluste      8232 May  6 13:03
>> >>     qb-cib_rw-response-25035-25036-12-header
>> >>     -rw-------    1 hacluste hacluste    540672 May  6 13:03
>> >>     qb-cib_rw-response-25035-25036-12-data
>> >>     And many more..
>> >>
>> >>     We have limited space in /dev/shm and all these files are filling it
>> >>     up. Are these all needed? Any way to limit? Do we need to do any
>> >>     clean-up if pacemaker termination was not graceful? What's the
>> > recommended size for this folder for Pacemaker? Our cluster will have
>> > maximum 6 nodes.
>> >
>> > -Regards
>> > Nikhil
>> >
>> > On Sat, May 14, 2016 at 3:11 AM, Ken Gaillot <kgaillot at redhat.com>
>> wrote:
>> >
>> >> On 05/08/2016 11:19 PM, Nikhil Utane wrote:
>> >> > Moving these questions to a different thread.
>> >> >
>> >> >     Hi,
>> >> >
>> >> >     We have limited storage capacity in our system for different
>> folders.
>> >> >     How can I configure to use a different folder for
>> /var/lib/pacemaker?
>> >>
>> >> ./configure --localstatedir=/wherever (defaults to /var or
>> ${prefix}/var)
>> >>
>> >> That will change everything that normally is placed or looked for under
>> >> /var (/var/lib/pacemaker, /var/lib/heartbeat, /var/run, etc.).
>> >>
>> >> Note that while ./configure lets you change the location of nearly
>> >> everything, /usr/lib/ocf/resource.d is an exception, because it is
>> >> specified in the OCF standard.
>> >>
>> >> >
>> >> >
>> >> >     Also, in /dev/shm I see that it created around 300+ files of
>> around
>> >> >     250 MB.
>> >> >
>> >> >     For e.g.
>> >> >     -rw-rw----    1 hacluste hacluste      8232 May  6 13:03
>> >> >     qb-cib_rw-response-25035-25038-10-header
>> >> >     -rw-rw----    1 hacluste hacluste    540672 May  6 13:03
>> >> >     qb-cib_rw-response-25035-25038-10-data
>> >> >     -rw-------    1 hacluste hacluste      8232 May  6 13:03
>> >> >     qb-cib_rw-response-25035-25036-12-header
>> >> >     -rw-------    1 hacluste hacluste    540672 May  6 13:03
>> >> >     qb-cib_rw-response-25035-25036-12-data
>> >> >     And many more..
>> >> >
>> >> >     We have limited space in /dev/shm and all these files are filling
>> it
>> >> >     up. Are these all needed? Any way to limit? Do we need to do any
>> >> >     clean-up if pacemaker termination was not graceful?
>> >> >
>> >> >     -Thanks
>> >> >     Nikhil
>> >> >
>> >> >
>> >> >
>> >> >
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>>
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