[linux-lvm] The benefits of lvmlockd over clvmd?

[Eric Ren]

Hi David,

Regarding the question of the subject, I can think of three main 
benefits of lvmlockd over clvmd:

- lvmlockd supports two cluster locking plugins: dlm and sanlock. 
sanlock plugin can supports up to ~2000 nodes
  that benefits LVM usage in big virtulizaton/storage cluster, while dlm 
plugin fits HA clsuter.

- lvmlockd has better design than clvmd. clvmd is command-line level 
based locking system, which means the
  whole LVM software will get hang if any LVM command gets dead-locking 
issue. However, lvmlockd is *resources* based
cluster locking. The resources to protect is VG and LV so that the 
deadlock issue will be isolated inside the resource and
operations on other VG/LV can still proceed.

- lvmlockd can work with lvmetad.

But, I may be wrong in some points. Could you please help correct me and 
complete the benefit list?

Thanks!
Eric