MSA Storage

Business Copy on SAN EVA


Business Copy on SAN EVA

I was wondering if anyone can confirm if you should be able to run to snap and mount jobs onto the same server at the same time?

I have disks on two servers (win2k) that need to be snapped and mounted onto a backup server (win2k) before I start batch processing runs against the live databases on these machines. If I run the jobs together they fail an only seems to have been an issue since moving the backup server from NT.

I am currently running the jobs one after the other in our batch scheduling software but this is putting a dependency on the first job completing before the 2nd starts so I was wondering is this a limitation of BC or do I have a problem with my implementation?
Regular Advisor

Re: Business Copy on SAN EVA


I suppose you can't do that.
When you take one snap or mirror for one volume which is used by os.The OS must write some info in this volume.This will copy when you use the snap job.If you mout the snap volume to the same server,the server must has two same volumes;so it's wrong.
After you do the snap job,you would mout the snap volume to other server and use it to backup or other jobs.And different os will not mout this volume.
Uwe Zessin
Honored Contributor

Re: Business Copy on SAN EVA

Presenting a Snap to the same server as the parent disk is an absolute NO-NO in the Windows world as the OS does not have any code to deal with these conflicts.

I have played with this on the HSG and it also killed the Secure Path setup.

It is also possible that such a situation screws up the cluster database.

Re: Business Copy on SAN EVA

Thanks for your replies but I am not trying to mount the snap back to the same server.

Ok let me try to explain better.

Dataserver1 and Dataserver2 at the end of day carry out some processing. After this is completed a snap and mount is carried out on each of these machines onto backupserver1 where they are backed up.

On occasion these two snap and mounts fail and I think it maybe due to the two of them running at the same time. The only way to get round this seems to be a BCRegClean and then reboot. This only happens occasionally and as the amount of processing each server is required to do before the snap mount differs every night I think it is down to when they run at the same time.

This failure only seems to have come about recently when we upgraded the backupserver1 from NT to 2K. It may have been that the mount jobs never conincided before but it has been running with this setup for over a year without any problems previously. I can only assume it is related to the way win2k redetects of the disks when they are mounted?

I was just wondering if anyone else could confirm that this is the case (i.e. you can't run two mount jobs to the same server at same time to w2k server). I have got round it as I said above by running one process -> snap/mount and then the second process -> snap/mount but this means if there is a problem with the first the second won't run which is what I am trying to get away from.