topic Re: how do I share filesystem on cluster in Operating System - HP-UX

how do I share filesystem on cluster

AMSA Unix Admin — Sat, 04 Jan 2003 00:33:39 GMT

Hello,

Is it possible to mount an SLVM filesystem on 2 cluster nodes at the same time? I have SLVM and Oracle RAC w/ shared raw partitions working ok. However I have other shared disks that I would like to slvm and put a filesystem on and mount r/w on both nodes at the same time. Can I do it? I don't really see instruction how. I tried it but the files created on one node were not visible on the other node. And the mount on 2nd node complained that volume was dirty, etc. Please advise. I'm fairly new to MC/SG environment.

Thanks and regards,

Chuck Davis

Re: how do I share filesystem on cluster

James Murtagh — Sat, 04 Jan 2003 02:00:57 GMT

Hi,

I'm afraid you can't do this with standard filesystems at the moment. There is no way for the kernels on both servers to synchronise and prevent file/metadata corruption.

However, you could always use HA NFS for this?

Regards,

James.

Re: how do I share filesystem on cluster

Ashwani Kashyap — Sat, 04 Jan 2003 02:11:17 GMT

At this time HPUX doesnot have this feature . You will have to wait until they finish porting some of these features from true64 and vms to hpux .

Re: how do I share filesystem on cluster

Vincent Fleming — Sun, 05 Jan 2003 14:20:33 GMT

As of today, you can mount the FS on the second server Read Only, but not Read/Write. It's an optional feature, which at the moment, I forget the name of.

Anyway, it's true that clustered filesystems are part of True64 (AFS), and are being ported to HP-UX. Last I heard, it should be available in late '03 or early '04.

Meanwhile, I would suggest using NFS to get the same effect, even if the performance is not as good as directly mounting the device.

Good luck,

Vince

Re: how do I share filesystem on cluster

Vincent Fleming — Mon, 06 Jan 2003 14:18:30 GMT

Because someone just sent me an email questioning this, here's a link to Veritas' website on this product (by the way, it's called File Sharing Option, or FSO):

http://www.veritas.com/products/category/ProductAddOnDetail.jhtml?productId=filesharingoptionhpux

Vince

Re: how do I share filesystem on cluster

AMSA Unix Admin — Mon, 06 Jan 2003 14:34:25 GMT

Thanks for the info. No wonder I couldn't find documentation on it! I may give a try at the RO mount option on 2nd node. That would probably be sufficient good for our purposes.

Regards,

Chuck Davis

Re: how do I share filesystem on cluster

Vincent Fleming — Mon, 06 Jan 2003 14:47:02 GMT

Nooooooo!!!!

You *need* this optional poroduct for the second node to mount the filesystem. Please read the docs carefully, as you can panic your system mounting the filesystem RO (or any way) without this product!!!!

Good luck,

Vince

Re: how do I share filesystem on cluster

A. Clay Stephenson — Mon, 06 Jan 2003 15:21:04 GMT

I concur with Vincent without the FSO addon to VxFS even a second read-only mount will yield inconsistant results. The 2nd system will be clueless about the 1st system's buffer cache. Sharing can only work if all the hosts mount the filesystem read-only (unless you purchase the Veritas add-on). It allows one box to be read-write and multiple other hosts to mount RO and still keep the various system buffer caches consistant. You could, of course, opt to use an NFS mount.

Re: how do I share filesystem on cluster

AMSA Unix Admin — Mon, 06 Jan 2003 15:56:51 GMT

Thanks for the clarification. I expected there would be buffer issues but I my initial consideration (now abandoned) would have been for a fairly static filesystem with maybe the occasional sync if things looked weird. As for now, I will setup nfs between the nodes. I look forward to having the cluster file system available in the future since w/ nfs one node is dependent on the other (and we didn't buy the HA nfs product which may(?) help resolve the dependency).

Thanks again for the help!

Chuck Davis