RE: Instance Initialization Problem

Additionally, you can use Solaris' "format" command to accomplish the same thing without the use of Informix offsets. Given that "format" can only slice a disk into seven partitions, if you are only creating a few chunks on each drive you can create a 4k partition starting at cylinder 0 to "mask" off the Solaris disk label information. Then format the rest of the drive for use as your Informix chunks. Each chunk can then have an Informix offset of 0. Just my $0.02... -Dave David A. Buchholz Senior Database Administrator Cendant Incorporated david.buchholz@hit.cendant.com Voice: 602.220.5853 -----Original Message----- From: Art S. Kagel [mailto:kagel@bloomberg.net] Sent: Monday, May 03, 1999 12:55 PM To: informix-list@iiug.org Subject: Re: Instance Initialization Problem Lloyd AJ Wilson wrote: > > Hello, > > We are currently working with Informix Online 7.12 UC1 and we are having > difficulties initializing our informix instance. Our servers run 128MB > memory on a dual Ultra Sparc UNIX 300MHZ processors with 3 18GB ultra > fast scsi hard drives. Each time we bring an instance online and then > back to off line we can no longer initialize our instance using the same > raw partition that the rootdbs was created on. [SNIP] There it is! You have stated the problem exactly. I assume the disk partitions are native Solaris/SunOS partitions and you are using them as RAW chunks. The problem is that Solaris writes the partition table entry for each disk partition onto the first 4K of each partition and NOWHERE ELSE! So if you created the Informix chunk with an offset of zero it overwrote the partition information of the first partition and when you next try to open the RAW file, by bringing the engine back up again, Solaris not only cannot find that partition but it will not be able to find any following partitions either. If you use native Solaris partitions you MUST use an offset of 4K for EVERY chunk (this will reduce the maximum size of a chunk from just under 2GB by an additional 4K but it cannot be helped). The only other option is to use a volume manager, like Veritas VM, which keeps its partitioning metadata in a section of the drive which is unavailable to the OS or Informix. (BTW you never see this problem when you create filesystems on Solaris because mkfs knows about the partition metadata and skips over it. Informix has no such knowledge.) Art S. Kagel