Chunk size limit with 4 byte pages (64 bit Solaris)

Someone posted a message regarding Raw vs Cooked configuration about a month ago. There was one thread I read that I am now trying to find but it seems to be gone and I can't find it in the archive on iiug. There was a discussion about the fact that Solaris has a limit to the # of partitions, and since Informix has a chunk size limitation you can end up wasting space on extremely large disks (>14 gig). Someone said that if you go to the 64 bit version of Solaris - you can use a 4 byte page size rather than a 2 byte page size - thus increasing the size of the chunks to 4 gig. Can anyone confirm this? Or - do you know where I can find the recently archived postings? I called Informix Tech support and they are checking for me - but I figured someone here would probably remember. Regards, Greg Schin

I am not sure about the page size, but you can still use chunks larger than 2 gig in 32 bit Solaris. The only implications are that you have to use raw space and be very carefull specyfing offsets when you add the chunks to the dbspaces. You can have a 4 gig chunk and specify the first chunk with offset of 0 that is 2Gb large and second chunk that has offset of 2097152 (1024 KB * 1024 * 2) and size of 2GB.

Paul Jazwierski wrote: > I am not sure about the page size, but you can still use chunks larger > than 2 gig in 32 bit Solaris. The only implications are that you have to > use raw space and be very carefull specyfing offsets when you add the > chunks to the dbspaces. You can have a 4 gig chunk and specify the first > chunk with offset of 0 that is 2Gb large and second chunk that has > offset of 2097152 (1024 KB * 1024 * 2) and size of 2GB. You may be able to do that (which I doubt), but it is not supported. Heiko

Informix says that IDS 7.x and 9.x do not allow 4 Kbyte page size. They said that XPS 8.3 does allow for 4 Kbyte page sizes. So it does work on XPS 8.3. The guy at Informix did recommend using the offsets to get around the limitation and did not indicate there would be a problem (or that it was not supported).

I tried it once on SCO OpenServer. It has the same limitations. Informix on SCO does not even allow offsets larger than 2GB (it makes sense for me, when they use 32-bit-signed values as lseek does). In the thread you mentioned I learned that I can divide my disk into 4 partitions each 7 divisions. So I get 4 partitions x 7 divisions x 2 GB = 56 GB maximum disk size. But it might not work on solaris. There are 2 possible solutions out of it: 1) use a logical volume manager 2) use cooked space Using cooked space you specify a offset of 0 and size of 2 GB. You can use as many files you want. It is a matter of solaris to handle adressing. In the thread we discussed performance of cooked space. Someone mentioned about 20-30% performace-loss in cooked space. And a loss of consistency when the system crashes. You can read the discussion in http://www.deja.com. Search for Informix and cooked. Tommi Mäkitalo Dr. Eckhardt + Partner GmbH In article <38A319D5.DC7E95B3@earthlink.net>, Paul Jazwierski <uszko@earthlink.net> writes: > I am not sure about the page size, but you can still use chunks larger > than 2 gig in 32 bit Solaris. The only implications are that you have to > use raw space and be very carefull specyfing offsets when you add the > chunks to the dbspaces. You can have a 4 gig chunk and specify the first > chunk with offset of 0 that is 2Gb large and second chunk that has > offset of 2097152 (1024 KB * 1024 * 2) and size of 2GB. > >