RE: [Question] Does the kernel ignore errors writng to disk?

[Miller, Mike (OS Dev)]

> -----Original Message-----
> From: Alan Cox [mailto:alan@xxxxxxxxxxxxxxxxxxx] 
> Sent: Thursday, April 28, 2005 9:58 AM
> To: Miller, Mike (OS Dev)
> Cc: Linux Kernel Mailing List; linux-scsi@xxxxxxxxxxxxxxx; 
> brace@xxxxxx
> Subject: Re: [Question] Does the kernel ignore errors writng to disk?
> 
> On Mer, 2005-04-27 at 19:40, mike.miller@xxxxxx wrote:
> > It looks like the OS/filesystem (ext2/3 and reiserfs) does 
> not wait for for a successful completion. Is this assumption correct?
> 
> Of course it doesn't. At 250 ops/second for a decent disk no 
> OS waits for completions, all batch and asynchronously queue 
> I/O. See man fsync and also O_DIRECT if you need specific "to 
> disk" support. If you do that be aware that you must also 
> turn write caching off on the IDE disk. I've repeatedly asked 
> the "maintainer" of the IDE layer to do this automatically 
> but gave up bothering long ago. Without that setting users 
> are playing with fire quite honestly.
> 
> The alternative with latest 2.6 stuff is to turn on Jens 
> Axboe's barrier work which seems to give better performance 
> on a drive new enough to have cache flush operations.
> 
> Alan
Thanks, Alan. I'll try Jens barrier.

> 
> 
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