freebsd-dev/sys/ufs
Bruce Evans 1874ef935c Quick fix for breakage of read clustering on non-IDE drives. Read
clustering is obsolescent technology so hardly anyone noticed.  On
a DORS 32160 SCSI drive with 4 tags, read clustering makes very
little difference even for huge sequential reads.  However, on a
ZIP SCSI drive with 0 tags, the minimum overhead per block is about
40 msec, so very large clusters must be used to get anywhere near
the maximum transfer rate.  Using clusters consisting of 1 8K block
reduces the transfer rate to about 250K/sec.  Under msdosfs, missing
read clustering is normal and a cluster size of 1 512 byte block
reduces the transfer rate to about 25K/sec.

Broken in:	rev.1.18
1998-08-18 03:54:39 +00:00
..
ffs Removed unused includes. 1998-08-17 19:09:36 +00:00
mfs Fixed printf format errors. 1998-07-11 07:46:16 +00:00
ufs Quick fix for breakage of read clustering on non-IDE drives. Read 1998-08-18 03:54:39 +00:00