topic Re: OPEN-V-CM? in Disk Enclosures

OPEN-V-CM?

Hanry Zhou — Wed, 08 Oct 2008 14:10:56 GMT

I have a few luns showing me OPEN-V-CM, in the result of ioscan -fnC, as usually it should show me OPEN-V on hpux11i servers.

These luns on xp12000, and they are all small pieces, like only 100M, I am wondering what made them to show OPEN-V-CM.

Thanks,

Re: OPEN-V-CM?

IBaltay — Wed, 08 Oct 2008 15:06:13 GMT

Hi,
those should be the Raid Manager command devices, used for the XP Business Copy and Continuous Access control operations

Re: OPEN-V-CM?

Hanry Zhou — Thu, 09 Oct 2008 13:08:02 GMT

But we don't have the license for Bussiness Copy or Continues Access as you mentioned?

Re: OPEN-V-CM?

IBaltay — Thu, 09 Oct 2008 13:12:12 GMT

Ok,
do you have any external storage in your environment pls?

Re: OPEN-V-CM?

IBaltay — Thu, 09 Oct 2008 13:12:58 GMT

XP external storage certainly

Re: OPEN-V-CM?

IBaltay — Thu, 09 Oct 2008 13:23:41 GMT

Most likely it can be the residuum of some RAID manager (local or remote Raid manager command devices)installations or something like that...

Re: OPEN-V-CM?

Hanry Zhou — Thu, 09 Oct 2008 17:09:50 GMT

Based on documets, these are Command Devices, but what are they for? conceptually why do I need command devices? and and consequences if I assign them to a host?

Thanks,

Re: OPEN-V-CM?

IBaltay — Thu, 09 Oct 2008 17:26:51 GMT

command devices are special XP volumes which accepts the XP RAID manager (RM) BC and CA controll operations (metadata)
therefore they are so small,
there should not be any data on them, because serving as a command devices they are inaccessible for data operations, they are dedicated to the RM metadata operations.
If you are absolutely sure you do not need them, you can release them into the free space...

Re: OPEN-V-CM?

krusty — Thu, 09 Oct 2008 17:30:10 GMT

These are basically pass through devices so a host can communicate in band to the XP array. As stated in the thread, these devices are typically mapped to hosts where a scripting utility (RAID Manager) is installed so you can tell the array to perform certain functions (like split a Business Copy).

These devices are typically very small (35 or 46 MB), and data should not be written to them. You can change from a Command Device to a data LUN from the XP console.

Sincerely,

Curt