vg activated on 2 nodes

[Roberto Gallis]

Hi all,
I have 2 web servers using same datas.
I'd like to try to activate a vg on 2 nodes,
in the first node in read/write mode, in the second node in read-only mode.
The vg is on a xp256. This VG is not on a SG package.
Anyone had some experience? Can I have some problem when I write files from first node?

Regards

Roberto

[Vincenzo Restuccia]

No problem,in node 1 #vgchange -a y,in node 2
#vgchange -a r

[Manju Kampli]

Roberto,

U must be crazy to do this.. I don't know why you want to activate VG on two systems. This will lead to corruption of Volume group and is not supported by HP.

If it is for sharig the file systems, do a NFS export from one system and mount it as read only on other system. As you may know, this will be slow because of network limitation.

Hope this helps
Manju

[Roberto Gallis]

Hi,
I'm not crazy.. simply I'd like to know if it is possible to do and if someone had some experience of mounting a vg in read-only with an other system.

Thanks all
Best regards
Roberto

[melvyn burnard · Accepted solution]

This is of course possible, but not recommended.
I guess the biggest query woul dbe what is the effect on the node you are activating read-only, when you update on the "active" node?

Well I think that the in-core inode info might not get updated so you may have to continually unmont and remount file systems on the read-only node to ensure any data is updated.
But if that is not an issue, then yes it can and does work, particularly for doing backups on the read-only node.
I guess you would need to test it and make yourself comfortable with it.