is there a user mode way to flush disk cache

From: Eric Taylor (et2_at_rocketship1.com)
Date: 10/20/05 

Date: Wed, 19 Oct 2005 20:03:38 -0700

I'm using 2.6 from rhel4 and I need to write 2 gig files quickly.

I don't care if the 2 gigs is all in the cache and nothing has
written to disk yet. I've got plenty of memory.

I need the 2 gig writes to "complete" in less than 30 seconds.
Sometimes when it gets stuck, it can take over 5 mintues and
the disk led is on solid. This seems slow to me.

I find that I can get the writes to complete the fastest if the
disk cache is nearly empty before I start. Otherwise, even
though one would think there was plenty of room left, something
hangs my program while doing writes.

My klutzy way to flush the caches is to write 8 two-gig files in
sucessesion and them rm them all.

There's gotta be a better way than this.

thanks
eric

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