Re: raw device dbspace size >2GB

> The problem is not Informix's. Informix uses lseek() and fseek() to > position within the file and the limit of the offset that the standard > UNIX/POSIX seek library functions use are limited to 2GB. Informix's code > always offsets from the beginning of the file not relative so the useable > chunk (OFFSET + SIZE) is 2GB. On 64bit versions (I think the version > letters start with H rather than the U for 32bit UNIX) the extended 64bit > seek functions could be used and the chunk limit would be removed. 64-bit ports are .FCx, 32-bit on 64-bit UNIX are .HCx I think that even if 64-bit seek functions were used, there'd be a significant change in the IDS architecture...I guess someone more intimate with the internals would be able to address that better...

Chuck Renaud wrote: > > The problem is not Informix's. Informix uses lseek() and fseek() to > > position within the file and the limit of the offset that the standard > > UNIX/POSIX seek library functions use are limited to 2GB. Informix's code > > always offsets from the beginning of the file not relative so the useable > > chunk (OFFSET + SIZE) is 2GB. On 64bit versions (I think the version > > letters start with H rather than the U for 32bit UNIX) the extended 64bit > > seek functions could be used and the chunk limit would be removed. > > 64-bit ports are .FCx, 32-bit on 64-bit UNIX are .HCx > > I think that even if 64-bit seek functions were used, there'd be a > significant change in the IDS architecture...I guess someone more > intimate with the internals would be able to address that better... Some clarification on the chunk size issue: * for all 32 bit ports the sum of chunk size + chunk offset may not be larger than 2GB (i.e. a volume manager/partition manager would have to be used to allocate chunks past 2 GB on a disk larger than 2 GB). * for all 64 bit ports the chunk size may not be larger than 2GB, BUT the sum of chunk size + chunk offset is allowed to be larger than 2GB (no volume manager/partition manager required for disks larger than 2GB). Now there are some platforms with a page size of 4KB which allow (check the output of 'onstat -b' for buffer size) which may allow chunks of upto 4 GB. This should be documented in the release specific information for the server version ($INFORMIXDIR/release/en_us/0333/*). Regards, Heiko =============== all standard disclaimers apply ================