Re: [UD] RFS and SAN storage
[EMAIL PROTECTED] (Doug Miller) wrote on 03/24/2004 11:45:32 AM: With the MC Service guard they can TOC a system (Transfer of control) at a drop of a hat and be back up and running on the 2nd machine very quickly. The 2nd machine grabs the ip address of the primary and people just have to log in again and pick back up where they were. I agree with Doug - this can be a very slick implementation if done correctly. I've worked with RFS installations on HP-UX with MC/ServiceGuard, and on AIX with HACMP. The clustering software nicely handles the fail-over, with the assumption that UniData is running with RFS to handle the cleanup. However, it's critical to ensure that UniData is set up correctly in the shared environment. There are components that need to be available on the shared disk, and other components that need to be unique to each system. If all of the pieces aren't in the right places, the TOC could result in a failure when starting UniData, or an invalid RFS recovery. Tread softly and test thoroughly when implementing this sort of solution. Also make sure the clustered environment is set up by somebody that understands it inside and out. This can be very complex to implement. Back to the original question, there's no fundamental problem with running RFS over a SAN. If at all humanly possible, you'll want to isolate the before-image, after-image, file-level, and archive logs from the database files. This is important for performance, since you don't want heads and controllers busy updating the database and log files at the same time. Also, if there is an unrecoverable media failure (not too likely these days, but it does happen!), you don't want it to take out the database files the archive logs at the same time. Otherwise you'll have to resort to your backups with no way to recover to the point of the failure. Tim Snyder IBM Data Management Solutions Consulting I/T Specialist , U2 Professional Services [EMAIL PROTECTED] -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: [UD] RFS and SAN storage
Thanks Rodney, Can you confirm that you do use RFS? If you have 30GB files then they must be dynamic, so they must be OK on SAN too. Cheers, Ken -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Baakkonen, Rodney We have been using a Hitachi SAN with Veritas for several years on a Solaris machine. We moved there from a DG environment using mirrored disks. I can't think of anything to note about the change. We have a couple of files aproaching 30 gig in size. The SAN has performed well. We are on Unidata 5.2 but in the process of moving to 6.0. We have been on a SAN since 2002. - ROd -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
RE: [UD] RFS and SAN storage
We have been using a Hitachi SAN with Veritas for several years on a Solaris machine. We moved there from a DG environment using mirrored disks. I can't think of anything to note about the change. We have a couple of files aproaching 30 gig in size. The SAN has performed well. We are on Unidata 5.2 but in the process of moving to 6.0. We have been on a SAN since 2002. - ROd -Original Message- From: Ken Wallis [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 24, 2004 1:41 AM To: [EMAIL PROTECTED] Subject: [UD] RFS and SAN storage Although there aren't many people here who make use of UniData's RFS facility, I know there are a few. I'm hoping that one or two of those might have some experience (good or bad) of setting up RFS files which are physically located on a SAN rather than on local disk. A client of mine is has a policy that all application data should, where possible, be stored on their EMC SAN instead of on local disks. They don't, however have a machine I can use for testing at this point that can access their SAN storage. At the moment this client is on Tru64 UNIX, and we know that there is no problem with UniData recoverable files on Compaq SAN storage, but the direction is away from HP/Compaq Tru64 and towards either AIX or Solaris utilising EMC SAN storage via Veritas. Has anybody either had this working, or tried to make it work and failed miserably? Current UniData version is 5.2, will move to 6.0.8 or higher probably at the same time as switching to SAN disks. Cheers, Ken -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users -- u2-users mailing list [EMAIL PROTECTED] http://www.oliver.com/mailman/listinfo/u2-users
