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Re: [linux-lvm] mirrored LV + cmirror problem



That's the problem. (C)LVM does not currently have a way to handle the disappearance of a device from just one machine... it expects a similar view of devices from all machines in a cluster. "Locking" on the second node fails because it doesn't know what to do with the disk that it sees (that has been removed from the node suffering the failure).

There is someone working handling orphaned/removed devices that reappear (which would be similar to this case), but I'm not sure if they've taken this scenario into account. I'll let him know about this.

 brassow

On Feb 18, 2008, at 10:48 AM, Lajkó Attila wrote:

Yes, I disconnected the lun via the Vtrak GUI from one of the nodes (el4).

Attila

On Feb 18, 2008, at 5:08 PM, Jonathan Brassow wrote:

How are you performing the failures? It looks like just one machine is loosing its connection to the device, while the other machines links remain in place.

brassow

On Feb 17, 2008, at 6:49 AM, Lajkó Attila wrote:

Here is the output of vgreduce:
ftp://ftp.ulx.hu/upload/clvmd/vgreduce.tar.gz

Attila


2008. febr. 15, 22:06 DU dátummal Jonathan Brassow <jbrassow redhat com >
ezt írta:

If the problem is reproducible, we should be able to track it down.

When a failure happens, the kernel sends an event to userspace that
signals 'dmeventd' to take action. If we take dmeventd out of the
picture, we can run the commands ourselves with higher verbose
settings.

When you activate the volume, you can 'lvchange -ay --monitor n <vg>/
<lv>' - this will prevent dmeventd from monitoring the mirror. Then
kill the log device. Finally, run 'vgreduce --removemissing <VG> -
vvvv' to perform the recovery. (redirecting all the output to a file
will give us something to look at if the failure is reproduced.)

We may need to grab debugging output from clvmd too, but that can get
messy, so we'll start with this.

brassow

P.S. It looks like you must have *.debug; in your /etc/syslog.conf,
yes?

On Feb 15, 2008, at 10:17 AM, Lajkó Attila wrote:



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read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/


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



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