spreading data evenly across disks

Hi, I have a large database that is occupying 3 9Gb disk units. The dbspace is setup as 3 chunks, one on each of the disk units. However, when populating the database, data fills disk 1, then moves onto disk 2, but as yet disk 3 is unused. I would like to evenly spread my data across the three disks so that disk access is optimised. Is there a way of setting this up. - I do not want individual tables on assigned to different disks though or more than one dbspace. I am currently running IDS 7.3 on IRIX 6.5.4 Thanks Graham

The documentation for this engine has a great discussion on fragmentation of your data. It will provide you exactly the distribution plan you seek. :-) Check out the informix.com website, and download the docs if you haven't already. Tim Graham Crookham wrote: > > Hi, > > I have a large database that is occupying 3 9Gb disk units. The dbspace > is setup as 3 chunks, one on each of the disk units. > However, when populating the database, data fills disk 1, then moves > onto disk 2, but as yet disk 3 is unused. > I would like to evenly spread my data across the three disks so that > disk access is optimised. Is there a way of setting this up. - I do not > want individual tables on assigned to different disks though or more > than one dbspace. > I am currently running IDS 7.3 on IRIX 6.5.4 > > Thanks > > Graham -- - -- --- Tim Schaefer ---- tschaefe@mindspring.com --- http://www.inxutil.com -- -

Graham Crookham wrote: > > Hi, > > I have a large database that is occupying 3 9Gb disk units. The dbspace > is setup as 3 chunks, one on each of the disk units. > However, when populating the database, data fills disk 1, then moves > onto disk 2, but as yet disk 3 is unused. > I would like to evenly spread my data across the three disks so that > disk access is optimised. Is there a way of setting this up. - I do not > want individual tables on assigned to different disks though or more > than one dbspace. The best way to evenly spread the load across multiple drives is to use disk striping (RAID0) or some other RAID level that performs data striping (RAID3, RAID4, RAID5, RAID10). If you set up a stripe block size of say 24K each sequential 8K (or 4 pages) will be written to the next drive in the 3 drive stripe set round robin. If you decide to use one of the higher RAID levels, above level 0, that provide some redundancy you will have to install additional drives to get the same capacity as some storage is dedicated to recovery information. > I am currently running IDS 7.3 on IRIX 6.5.4 I do not know if IRIX supports striping or RAID or if one of the third party volume managers that do is available for it. Contact your vendor. Art S. Kagel RAID10 RAID10 RAID10 RAID10 RAID10 RAID10 RAID10 RAID10 RAID10 This subliminal message brought to you by the Save Our Data Council.