ESDI controller recommendations

Vernon Schryver vjs at calcite.UUCP
Tue Sep 5 06:14:17 AEST 1989

In article <1125 at virtech.UUCP>, cpcahil at virtech.UUCP (Conor P. Cahill) writes:
> Raw device support is not provided by the kernel, it is provided by the
> device driver.  Sometimes it makes sense for both the raw interface and
> block interface to both pass through the buffer cache, but for disk i/o
> all device drivers *should* not pass the raw i/o through the cache.  If 
> they did, fsck would have lots of trouble (especially when it told you 
> to reboot-no sync).
> | Conor P. Cahill     uunet!virtech!cpcahil      	703-430-9247	!
> | Virtual Technologies Inc.,    P. O. Box 876,   Sterling, VA 22170     |

Running fsck thru the buffer cache helps.  You don't suffer some of the
inconsistencies that otherwise occur.  Most of the need for the "reboot-no
sync" message goes away.  (BTW, in SVR3 for separate reasons, fsck does not
say that; it automatically re-mounts root.)  As long as the character
device reads & writes the correct bytes quickly, what does it matter to a
user process such as fsck how the driver (which many consider part of the
SVR3 kernel, even if it need not be in MACH) does its thing?

Vernon Schryver
vjs at calcite.uucp    or   ...{sgi,pyramid}!calcite!vjs

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