Re: Getting 'sync' to flush disk cache?

From: Robert Hancock
Date: Mon Aug 14 2006 - 19:08:20 EST

Jens Axboe wrote:
On Mon, Aug 14 2006, Arjan van de Ven wrote:
On Mon, 2006-08-14 at 14:39 -0400, Jeff Garzik wrote:
So... has anybody given any thought to enabling fsync(2), fdatasync(2), and sync_file_range(2) issuing a [FLUSH|SYNCHRONIZE] CACHE command?

This has bugged me for _years_, that Linux does not do this. Looking at forums on the web, it bugs a lot of other people too.
eh afaik 2.6.17 and such do this if you have barriers enabled...

That is correct, but it only works on reiserfs and XFS and user space
really cannot tell whether it did the right thing or not. File system
developers really should take this more seriously...

I was under the impression that this just worked under recent kernels. I'm disappointed to hear that it doesn't. It always annoys me that issues like this sometimes just seem to stick around forever in the kernel without getting the attention they should (and tend not to be well documented either..)

Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@xxxxxxxxxxxxx
Home Page:

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at