Bug 788096

(In reply to comment #0)
> [root@blond-vdsf ~]# pvs -o pv_name,vg_name
>   PV                                                    VG                      
>   /dev/mapper/1ATA_WDC_WD800JD-75MSA3_WD-WMAM9DEH4849p3 vg0                     
>   /dev/mapper/1Dafna-011328104                         
> 5938a153-5eae-42cf-8089-68a89f1aa2fd
>   /dev/mapper/1Dafna-021328104                         
> 5938a153-5eae-42cf-8089-68a89f1aa2fd
>   /dev/mapper/1Dafna-031328104                         
> 5938a153-5eae-42cf-8089-68a89f1aa2fd

> [root@blond-vdsf ~]# pvs -o pv_name,vg_name /dev/mapper/1Dafna-021328104
> /dev/mapper/1Dafna-011328104 /dev/mapper/1Dafna-031328104
>   PV                           VG                                  
>   /dev/mapper/1Dafna-011328104 5938a153-5eae-42cf-8089-68a89f1aa2fd
>   /dev/mapper/1Dafna-021328104                                     
>   /dev/mapper/1Dafna-031328104 5938a153-5eae-42cf-8089-68a89f1aa2fd

Hmm, interesting. Could you please rerun those pvs commands with the "-vvvv", grab the debug output it produces and attach it here. Also, attach the output of "lsblk" as well. Thanks.

unfortunately its not reproduced any more. 
after I remove a large number of lvs from my storage with -f option (not these ones) I got an error on map locks: 

  Internal error: Maps lock 15212544 < unlock 15974400

and since then the lun is shown correctly. 

so it might have been a lock issue on storage side 
storage is also rhel with package: 
lvm2-2.02.87-6.el6.x86_64

If there is anything I can get you from storage side I would be happy but the pv's are now shown correctly: 


[root@blond-vdsh tmp]# pvs -o pv_name,vg_name /dev/mapper/1Dafna-011328104 /dev/mapper/1Dafna-021328104 /dev/mapper/1Dafna-031328104
  PV                           VG                                  
  /dev/mapper/1Dafna-011328104 6c256292-6674-48f6-9742-39442e3d89cb
  /dev/mapper/1Dafna-021328104 6c256292-6674-48f6-9742-39442e3d89cb
  /dev/mapper/1Dafna-031328104 6c256292-6674-48f6-9742-39442e3d89cb

Could you be more specific with 'large' number ?

It might be you need to set bigger preallocated memory in /etc/lvm/lvm.conf file.
Look for  "reserved_memory" and set it to higher number (i.e. 32768 instead of 8192).

In future it might be more automatic, but for now user needs to give some memory hints to application if there is really a huge set of lvs.

(In reply to comment #3)
> Could you be more specific with 'large' number ?
> 
100 lv's (small one's, 1G each - created for specific test). 

> It might be you need to set bigger preallocated memory in /etc/lvm/lvm.conf
> file.
> Look for  "reserved_memory" and set it to higher number (i.e. 32768 instead of
> 8192).
> 
> In future it might be more automatic, but for now user needs to give some
> memory hints to application if there is really a huge set of lvs.

Ok - so ~700KB looks like VG write happened during some lvremove operation and I assume this has been addressed by this patch in version 2.02.89.

https://www.redhat.com/archives/lvm-devel/2011-November/msg00126.html

When there is larger mda size - it may easily go over the preallocated size,
even though in this case, the memory does not needed to be guarded at this moment.
In your case, specifying larger preallocated size would be probably fix the issue as well, with the version 2.02.89 your current size should be still good enough value.

The lock/unlock message is a side-issue.

For the original problem, please attach the output of 'pvs -o all -vvvv' from that system.  If that doesn't give us enough clues, then we'll close this as irreproducible.

(BTW You should use sosreport or lvmdump in future to capture the state of a
system for diagnosis.)

(In reply to comment #7)
> The lock/unlock message is a side-issue.
> 
> For the original problem, please attach the output of 'pvs -o all -vvvv' from
> that system.  If that doesn't give us enough clues, then we'll close this as
> irreproducible.

I cannot attach anything since the issue is no longer reproduced since I deleted the multiple lv's. 
moved bug to closed and if I manage to reproduce I will reopen it with all attached 

> 
> (BTW You should use sosreport or lvmdump in future to capture the state of a
> system for diagnosis.)

OK.  Well the original symptoms made it look like an internal lvm problem related to device/metadata caching.  We'll see whether anyone else encounters similar problems, but we are updating this code again in 6.3.

we have encountered this issue again.
seems like a lvm cash issue. 

please see depended bug for vdsm which causes some of our hosts to not see a vg created out of multiple targets hence the targets will not be connected. 

https://bugzilla.redhat.com/show_bug.cgi?id=798635


please contact us for reproduction. 

we have a script on our vds hosts that reproduces the issue.

Please attach "lvmdump -m" and output of "pvs -o all -vvvv".

Closing.

Reopen this if it happens again and you succeed in obtaining diagnostics.