Subject: Re: disks write-back cache
To: Manuel Bouyer <>
From: Greg A. Woods <>
List: tech-kern
Date: 04/28/2003 18:14:20
[ On Monday, April 28, 2003 at 23:11:38 (+0200), Manuel Bouyer wrote: ]
> Subject: Re: disks write-back cache
> > BTW, is there any plan/desire to make this new dkctl(8) manage such
> > things as the SCSI A?RE mode page settings, especially when such
> > settings might be common to other non-SCSI devices?
> No, I think this belongs to scsictl, they looks scsi-specific.
> What are AWRE and ARRE ?

Well, the AWRE and ARRE mode-page bits are indeed the SCSI-specific way
of saying "automatic sector reallocation on error" (for write and read,
respectively).  However if other types of storage interfaces have
similar features then the concept isn't really SCSI-specific.

Is there any way to control the bad-sector reallocation ability of
IDE/ATA drives that do this, or is it always done?

> > BTW, it would also be nice to have generic mode page editing in
> > scsictl(8), as well as specific AWRE & ARRE set&clear commands in either
> > scsictl(8) and/or dkctl(8).  :-)  (I keep building the old FreeBSD
> > "scsi" command to do this because I'm too lazy to re-jig the code to fit
> > into scsictl... :-)
> Yes. Are you volonteer ? :)

I'll certainly volunteer the mode-page edit code for scsictl if I ever
get around to it, but it seems that I usually end up under time pressure
when I have to edit mode page settings and so I just fall back to
building the old FreeBSD code for quick fixes!  ;-)

								Greg A. Woods

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