>>> On 3/23/2010 at 04:33 PM, Jin Xiong <[email protected]> wrote:
> Hello - > > This is my 1st or 2nd posting to this listserv - - I've been a subscriber > for a few years now and find the information here to be very helpful. > > I've seen a few postings around OCFS2 and realize that there are a few > customers using this technology on Linux on z. Now I have a situation at > one of my customers that I'd appreciate your feedback on. > > Here's the landscape: This customer has a 4TB OCFS2 file system. It is a > logical volume group that's composed of 208 3390 Mod-27's. The cluster is > composed of 2 nodes, and has 500 GB worth of files of various types stored > on the file system. They are running on SLES 10 SP3, and z/VM 5.4. > > The customer wanted to expand the cluster to two additional nodes, for a 4 > node cluster. They installed 2 additional servers, linked all the disks MW > in the user definitions, created the logical volume group on those servers, > and attempted a mount. They received the following error message: > > linz3s08:~ # mount -a > mount.ocfs2: Bad magic number in superblock while opening > device /dev/mapper/system-attachments > > Has anyone encountered this scenario? What should be done in this case? > > What is the best way to expand an established OCFS2 cluster to include new > members? Jin, This whole setup seems somehow wrong. I've always seen references to linking minidisks MW as being a sure way to guarantee data corruption/loss. I suppose that's because of the minidisk caching (MDC) that CP does, but I'm not sure that's the only reason. Perhaps it's a CMS only issue, but I sure wouldn't want to bet my business on it. Additionally, LVM in SLES10 is not cluster aware. In the SLES11 High Availability Extension, cLVM is, but in SLES10, only EVMS can provide that. Are they using EVMS, or LVM? If they really want to stay with SLES10 and are using LVM, I think they need to move to a non-LVM SCSI over FCP setup. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
