raid on shared storage

I'm going to run some kind of cluster using shared fiber channel disks with linux sw raid on top.

Is it possible to start a raid device on more than one machine? Is there any write access for example to the superblock structure when or after starting a raid device that might crash with a second instance doing the same?

I'm not talking about mounting file systems in parallel (btw, how do I detect that a filesystem is already mounted at a different node, does reiserfs indicate that somehow?) but simply about starting the md.

Thanks!

nils-henner

Not yet.

Activating the same md raid on more than one node will destroy your data, is the gist of it.

RHAT is working on dm-raid1.c to support this, I think. Daniel Philipps should know more.

Sincerely,
Lars Marowsky-Brée <[email protected]>

High Availability & Clustering
SUSE Labs, Research and Development
SUSE LINUX Products GmbH - A Novell Business

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No. Happened to me multiple times and I still have all the data.

It's not much of a problem if two machines are syncing the same mirror as long as it is not mounted on any. Once you have the mirror mounted on one of them, who knows what happens to the write you've just commited.

I don't know what happens on raid5 tho ...

Jure Pečar
http://jure.pecar.org/
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