RE: drive/block device write scheduling, buffer flushing?

[Nathan Black]

That is what I wanted to do...Write directly to the disk. But the
kernel(2.4.1) is caching the io...

-----Original Message-----
From: bert hubert [mailto:[e-mail]]
Sent: Wednesday, January 31, 2001 12:51 PM
To: Nathan Black
Cc: [e-mail]
Subject: Re: drive/block device write scheduling, buffer flushing?

On Wed, Jan 31, 2001 at 11:52:25AM -0500, Nathan Black wrote:
> I was wondering if there is a way to make the kernel write to disk faster.

> I need to maintain a 10 MB /sec write rate to a 10K scsi disk in a
computer,
> but it caches and doesn't start writing to disk until I hit about 700 MB.
At
> that point, it pauses(presumably while the kernel is flushing some of the
> buffers) and I will have missed data that I am trying to capture.

try opening with O_SYNC, or call fsync() every once in a while. Otherwise,
this sounds like an application for a raw device, whereby you can write
directly to the disk, with no caching in between.

Regards,

bert

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