Monday, April 2, 2007

lvm snap-shot + udev is a bad combination

Working on updating and enhancing the lvm-mgmt plugin which provides cloning features for filesystem-images in openQRM (NFS + Iscsi).
Progressed fine on this nice and sunny day but spend some hours to find out that lvm snap-shot + udev are not really good friends. It happens to me that it works "sometimes" and sometimes not.
-> very unsatisfying
Then i found out that the reason for that behaviour is udev trying to access/create the device file in the same moment then lvm is doing the snap-shot. Result is that the cloned lvm-device is in an unusable state (e.g. it is not mountable). The solution for that issue was a simple "killall udev" ;) Now it works stable and robust.

mood: progressing, relaxed, happy (found the solution)

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