[vox-tech] Linux Block Layer is Lame (it retries too much)

[Jeff Newmiller]

On Wed, 28 May 2003, Mike Simons wrote:

> On Wed, May 28, 2003 at 11:31:56AM -0700, Jeff Newmiller wrote:
> > On Tue, 27 May 2003, Mike Simons wrote:
> > >   Last week I was having problems with the ide layer... it retries
> > > way too many times.  I was trying to read 512 byte blocks from a dying
> > > /dev/hda (using dd_rescue which calls pread), for each bad sector the
> > > kernel would try 8 times, 

[...]

> > > - Any other ideas on how to pull the disk blocks?
> > 
> > Not easy ones. (Build your own device driver that doesn't use mmap.)
> 
>   Michael Wenk suggested using O_DIRECT on the open call, which is
> an excellent idea.  This was what the Oracle people at their Clustering 
> Filesystem talk.  I have one more failing hard drive around which I'm 
> going to try that on... 

Kudos to Michael.  I had no idea such a flag existed (it isn't in my
Debian manpage, nor in "Linux Application Development").

[...]

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