Two computers with one shared array?

I've got two computers connected to a JBOD array. On it I've got 3 VGs and a bunch of free disks. I'd like to use 2 of the VGs on one of the computers and the other VG on the other computer.

Should I still vgscan on both computers at startup and then vgchange -a y VG1 VG2 on the first computer and vgchange -a y VG3 on the other computer?

Is it safe to vgchange -a n on both computers or should I only vgchange -a n VGx ?

Can I change the LVGs in a VG or do I need to inactivate everything on the other computer while I do this and then vgscan after I'm done?

Regards,
/Sebastian

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hmm.. on HP, the LVM system lets you exclusively activate a VG.. does Linux LVM allow you to do this ?

----- Original Message -----
From: "Sebastian Andersson" <[email protected]>
To: <[email protected]>
Sent: Tuesday, August 07, 2001 2:31 PM
Subject: [linux-lvm] Two computers with one shared array?

Not yet - but we're working on it!

patrick

First advice: BE VERY CAREFUL!

vgchange simply affects the kernel's view of the metadata so you can do that any time you like on either node. similarly vgscan should also be OK to run at system startup because it only reads metadata and updates the local cache files.

If you need to do any changes you MUST vgchange -an on one machine before changing metatdata on the other. THEN do a vgscan before vgchange -ay.

So, yes the startup sequence of vgscan/vgchange is the same as for a single node system but *ANY* metadata changes must be done from one node while the other has no LVM data in kernel.

I feel a FAQ entry coming on!

patrick

P.S. Of course, if you actually want to share the data on the disks you could use GFS!