Re: Offsets

In article <352C87AA.3C85@mcmail.com>, Paul Watson <watson@mcmail.com> wrote: >Barry Klecka wrote: >> >> I have a question that I hope someone can >> answer. I have used both Informix Online 5.x and >> 7.x on various Unix platforms. I have never used >> the "offset" when adding chunks the the online >> engine. I was recently told that I should be using >> the offset when the chunk is a raw partition >> because the OS can overwrite the header of the raw >> partition(logical volume). Anyone have any >> answers? > >I believe this advice came about because the OS uses the first >track/cylinder/block to store various bits and pieces. Early disk >partitioners used to allow this area to allocated to user areas, hence >there was a possiblity of overwriting this area. Most OS's no longer >allow this area to be allocated when the disk is partitioned so you >shouldn't have a problem. But if you have any doubt I'd test it. > >-- >Paul Watson # >WF Software Ltd # It said run using Windows 95 >Tel: +44 1436 674629 # or better in the manual >Fax: +44 1436 678693 # so I used Unix >www.wfsoftware.co.uk # I know with HP/UX 10.x or 11.x an offset into the logical volume is not necessary, and using it will slow I/O because of the neccessity to calculate the offset into the phsical address. Ray