Re: O_DIRECT please; Sybase 12.5

Andi Kleen
2001-06-29T10:42:58Z

Dan Kegel <dank@kegel.com> writes:
>
> And what are the chances Sybase will support that flag any time
> soon? I just read on news://forums.sybase.com/sybase.public.ase.linux

When Sybase always submits its buffers block aligned (same requirement as
for raw io) you can do it with a simple LD_PRELOAD hack.

I hacked sapdb (which has source available unlike sybase) to do direct IO
and it seems to not hurt at least.

> It supports raw partitions, which is good; that might satisfy my
> boss (although the administration will be a pain, and I'm not
> sure whether it's really supported by Dell RAID devices).
> I'd prefer O_DIRECT :-(

LVM makes raw partitions much less worse than they used to be. It is
basically a file system of raw partitions; allowing you to move and resize
them.

-Andi