[linux-lvm] clvm: failed to activate logical volumes sometimes

Discussion:

Eric Ren

2017-04-14 10:27:16 UTC

Hi!

In cluster environment, lvcreate/lvchange may fail to activate logical volumes sometimes.

For example:

# lvcreate -l100%VG -n lv001 clustermd
Error locking on node a52cbcb: Volume group for uuid not found: SPxo6WiQhEJWDFyeul4gKYX2bNDVEsoXRNfU3fI5TI9Pd3OrIEuIm8jGtElDJzEy
Failed to activate new LV.

The log file for this failure is attached. My thoughts on this issue follows, for example on two nodes:
n1:
===
#lvchange -ay vg/lv1
...
clvmd will ask for peer daemon on n2
to activate lv1 as well

n2:
===
lvm need to find lv1 and the PVs for lv1,
in device cache which aims to avoid frequent scan all
disks. But if the PV(s) might not be available
in device cache, it responses n1 with errors....

We found that 'clvmd -R' can be a workaround before activating LV, because
what "clvmd -R" is to refresh device cache on every node as its commit message said:
===
commit 13583874fcbdf1e63239ff943247bf5a21c87862
Author: Patrick Caulfield <***@redhat.com>
Date: Wed Oct 4 08:22:16 2006 +0000

Add -R switch to clvmd.
This option will instruct all the clvmd daemons in the cluster to reload their device cache
==

I think the reason why clvm doesn't refresh device cache every time before activating LV,
is to avoid scanning all disks frequently.

But, I'm not sure if I understand this issue correctly, will appreciate much if someone can
help.

Regards,
Eric

Eric Ren

2017-04-20 08:06:17 UTC

Permalink

Hi!

This issue can be replicated by the following steps:
1. setup two-node HA cluster with dlm and clvmd RAs configured;
2. prepare a shared disk through iscsi, named "sdb" for example;

3. execute lvm cmds on n1:
lvm2dev1:~# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created
lvm2dev1:~ # vgcreate vg1 /dev/sdb
Clustered volume group "vg1" successfully created
lvm2dev1:~ # lvcreate -l100%VG -n lv1 vg1
Logical volume "lv1" created.
lvm2dev1:~ # lvchange -an vg1/lv1

4. disconnect shared iscsi disk on n2;
5. to activate vg1/lv1 on n1:
lvm2dev1:~ # lvchange -ay vg1/lv1
Error locking on node UNKNOWN 1084783200: Volume group for uuid not found:
TG0VguoR1HxSO1OPA0nk737FJSQTLYAMKV2M20cfttItrRnJetTZmKxtKs3a88Ri

6. re-connect shared disk on n2;
7. execute `clvmd -R` on n1; and then I can activate lv1 successfully.

In local mode, lvm will make a full scan on disks each time when lvmetad is disable. As we know,
lvmetad is also disable when clvm is in use, so that device cache can not be refreshed
automatically
when device is added or removed. We can solve this issue by executing "clvmd -R" manually. But,
in some auto scripts, it's boring to put "clvmd -R" before some lvm commands everywhere.

So, is there an option to enable full scan every time when lvm is invoked in cluster scenario?
Thanks in advance:)

Regards,
Eric

Post by Eric Ren
Hi!
In cluster environment, lvcreate/lvchange may fail to activate logical volumes sometimes.
# lvcreate -l100%VG -n lv001 clustermd
SPxo6WiQhEJWDFyeul4gKYX2bNDVEsoXRNfU3fI5TI9Pd3OrIEuIm8jGtElDJzEy
Failed to activate new LV.
The log file for this failure is attached. My thoughts on this issue follows, for example
===
#lvchange -ay vg/lv1
...
clvmd will ask for peer daemon on n2
to activate lv1 as well
===
lvm need to find lv1 and the PVs for lv1,
in device cache which aims to avoid frequent scan all
disks. But if the PV(s) might not be available
in device cache, it responses n1 with errors....
We found that 'clvmd -R' can be a workaround before activating LV, because
===
commit 13583874fcbdf1e63239ff943247bf5a21c87862
Date: Wed Oct 4 08:22:16 2006 +0000
Add -R switch to clvmd.
This option will instruct all the clvmd daemons in the cluster to reload their device
cache
==
I think the reason why clvm doesn't refresh device cache every time before activating LV,
is to avoid scanning all disks frequently.
But, I'm not sure if I understand this issue correctly, will appreciate much if someone can
help.
Regards,
Eric
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

emmanuel segura

2017-04-20 08:29:58 UTC

Permalink

maybe you are using an old clvm version, I rember that in the new
version you don't need to execute any command on the secondary node.

Post by Eric Ren
Hi!
1. setup two-node HA cluster with dlm and clvmd RAs configured;
2. prepare a shared disk through iscsi, named "sdb" for example;
lvm2dev1:~# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created
lvm2dev1:~ # vgcreate vg1 /dev/sdb
Clustered volume group "vg1" successfully created
lvm2dev1:~ # lvcreate -l100%VG -n lv1 vg1
Logical volume "lv1" created.
lvm2dev1:~ # lvchange -an vg1/lv1
4. disconnect shared iscsi disk on n2;
lvm2dev1:~ # lvchange -ay vg1/lv1
Error locking on node UNKNOWN 1084783200: Volume group for uuid not
found: TG0VguoR1HxSO1OPA0nk737FJSQTLYAMKV2M20cfttItrRnJetTZmKxtKs3a88Ri
6. re-connect shared disk on n2;
7. execute `clvmd -R` on n1; and then I can activate lv1 successfully.
In local mode, lvm will make a full scan on disks each time when lvmetad is
disable. As we know,
lvmetad is also disable when clvm is in use, so that device cache can not
be refreshed automatically
when device is added or removed. We can solve this issue by executing "clvmd
-R" manually. But,
in some auto scripts, it's boring to put "clvmd -R" before some lvm commands everywhere.
So, is there an option to enable full scan every time when lvm is invoked in
cluster scenario?
Thanks in advance:)
Regards,
Eric

Post by Eric Ren
Hi!
In cluster environment, lvcreate/lvchange may fail to activate logical volumes sometimes.
# lvcreate -l100%VG -n lv001 clustermd
SPxo6WiQhEJWDFyeul4gKYX2bNDVEsoXRNfU3fI5TI9Pd3OrIEuIm8jGtElDJzEy
Failed to activate new LV.
The log file for this failure is attached. My thoughts on this issue
===
#lvchange -ay vg/lv1
...
clvmd will ask for peer daemon on n2
to activate lv1 as well
===
lvm need to find lv1 and the PVs for lv1,
in device cache which aims to avoid frequent scan all
disks. But if the PV(s) might not be available
in device cache, it responses n1 with errors....
We found that 'clvmd -R' can be a workaround before activating LV, because
===
commit 13583874fcbdf1e63239ff943247bf5a21c87862
Date: Wed Oct 4 08:22:16 2006 +0000
Add -R switch to clvmd.
This option will instruct all the clvmd daemons in the cluster to
reload their device cache
==
I think the reason why clvm doesn't refresh device cache every time before activating LV,
is to avoid scanning all disks frequently.
But, I'm not sure if I understand this issue correctly, will appreciate
much if someone can
help.
Regards,
Eric
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

--
.~.
/V\
// \\
/( )\
^`~'^

Eric Ren

2017-04-20 08:45:32 UTC

Permalink

Hi!

Post by emmanuel segura
maybe you are using an old clvm version, I rember that in the new
version you don't need to execute any command on the secondary node.

Thanks for your reply! Yes, I don't need to execute any command on any
remote node. But, in such case, we need "clvmd -R" on one of the nodes.

BTW, my versions:
lvm2-clvm-2.02.120-72.8.x86_64
lvm2-2.02.120-72.8.x86_64

Regards,
Eric

Post by emmanuel segura

Post by Eric Ren
Hi!
In cluster environment, lvcreate/lvchange may fail to activate logical
volumes sometimes.
# lvcreate -l100%VG -n lv001 clustermd
SPxo6WiQhEJWDFyeul4gKYX2bNDVEsoXRNfU3fI5TI9Pd3OrIEuIm8jGtElDJzEy
Failed to activate new LV.
The log file for this failure is attached. My thoughts on this issue
===
#lvchange -ay vg/lv1
...
clvmd will ask for peer daemon on n2
to activate lv1 as well
===
lvm need to find lv1 and the PVs for lv1,
in device cache which aims to avoid frequent scan all
disks. But if the PV(s) might not be available
in device cache, it responses n1 with errors....
We found that 'clvmd -R' can be a workaround before activating LV, because
===
commit 13583874fcbdf1e63239ff943247bf5a21c87862
Date: Wed Oct 4 08:22:16 2006 +0000
Add -R switch to clvmd.
This option will instruct all the clvmd daemons in the cluster to
reload their device cache
==
I think the reason why clvm doesn't refresh device cache every time before
activating LV,
is to avoid scanning all disks frequently.
But, I'm not sure if I understand this issue correctly, will appreciate
much if someone can
help.
Regards,
Eric
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

emmanuel segura

2017-04-20 09:28:41 UTC

Permalink

But When I say any command, I mean "any clvmd -R", I used clvmd with
redhat 5.8(rhcs) and I never used clvmd -R when the devices changed,
only on the old redhat version.

Post by Eric Ren
Hi!

Post by emmanuel segura
maybe you are using an old clvm version, I rember that in the new
version you don't need to execute any command on the secondary node.

Thanks for your reply! Yes, I don't need to execute any command on any
remote node. But, in such case, we need "clvmd -R" on one of the nodes.
lvm2-clvm-2.02.120-72.8.x86_64
lvm2-2.02.120-72.8.x86_64
Regards,
Eric

Post by emmanuel segura

Post by Eric Ren
Hi!
1. setup two-node HA cluster with dlm and clvmd RAs configured;
2. prepare a shared disk through iscsi, named "sdb" for example;
lvm2dev1:~# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created
lvm2dev1:~ # vgcreate vg1 /dev/sdb
Clustered volume group "vg1" successfully created
lvm2dev1:~ # lvcreate -l100%VG -n lv1 vg1
Logical volume "lv1" created.
lvm2dev1:~ # lvchange -an vg1/lv1
4. disconnect shared iscsi disk on n2;
lvm2dev1:~ # lvchange -ay vg1/lv1
Error locking on node UNKNOWN 1084783200: Volume group for uuid not
found: TG0VguoR1HxSO1OPA0nk737FJSQTLYAMKV2M20cfttItrRnJetTZmKxtKs3a88Ri
6. re-connect shared disk on n2;
7. execute `clvmd -R` on n1; and then I can activate lv1 successfully.
In local mode, lvm will make a full scan on disks each time when lvmetad is
disable. As we know,
lvmetad is also disable when clvm is in use, so that device cache can not
be refreshed automatically
when device is added or removed. We can solve this issue by executing "clvmd
-R" manually. But,
in some auto scripts, it's boring to put "clvmd -R" before some lvm
commands
everywhere.
So, is there an option to enable full scan every time when lvm is invoked in
cluster scenario?
Thanks in advance:)
Regards,
Eric

Post by Eric Ren
Hi!
In cluster environment, lvcreate/lvchange may fail to activate logical
volumes sometimes.
# lvcreate -l100%VG -n lv001 clustermd
SPxo6WiQhEJWDFyeul4gKYX2bNDVEsoXRNfU3fI5TI9Pd3OrIEuIm8jGtElDJzEy
Failed to activate new LV.
The log file for this failure is attached. My thoughts on this issue
===
#lvchange -ay vg/lv1
...
clvmd will ask for peer daemon on n2
to activate lv1 as well
===
lvm need to find lv1 and the PVs for lv1,
in device cache which aims to avoid frequent scan all
disks. But if the PV(s) might not be available
in device cache, it responses n1 with errors....
We found that 'clvmd -R' can be a workaround before activating LV, because
===
commit 13583874fcbdf1e63239ff943247bf5a21c87862
Date: Wed Oct 4 08:22:16 2006 +0000
Add -R switch to clvmd.
This option will instruct all the clvmd daemons in the cluster to
reload their device cache
==
I think the reason why clvm doesn't refresh device cache every time before
activating LV,
is to avoid scanning all disks frequently.
But, I'm not sure if I understand this issue correctly, will appreciate
much if someone can
help.
Regards,
Eric
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

--
.~.
/V\
// \\
/( )\
^`~'^