cfs(4) [plan9 man page]

CFS(4)							     Kernel Interfaces Manual							    CFS(4)

NAME

       cfs - cache file system

SYNOPSIS

       cfs -s [-rd] [-f partition]

       cfs -a netaddr [-rd] [-f partition] [mtpt]

DESCRIPTION

       Cfs is a user-level file server that caches information about remote files onto a local disk.  It is normally started by the kernel at boot
       time, though users may start it manually.  Cfs is interposed between the kernel and a network connection to a remote file server to improve
       the  efficiency of access across slow network connections such as modem lines.  On each open of a file cfs checks the consistency of cached
       information and discards any old information for that file.

       Cfs mounts onto mtpt (default /) after connecting to the file server.

       The options are:

       s      the connection to the remote file server is on file descriptors 0 and 1.

       a netaddr
	      dial the destination netaddr to connect to a remote file server.

       r      reformat the cache disk partition.

       d      turn on debugging

       f partition
	      use file partition as the cache disk partition.

       All 9P messages except read, clone, and walk (see intro(5)) are passed through cfs unchanged to the remote server.  A clone followed  imme-
       diately	by a walk is converted into a clwalk.  If possible, a read is satisfied by cached data.  Otherwise, the file server is queried for
       any missing data.

FILES

       /dev/hd0cache
	      Default file used for storing cached data.

SOURCE

       /sys/src/cmd/cfs

																	    CFS(4)

WREN(3) 						     Library Functions Manual							   WREN(3)

NAME

       wren, ata - hard disk interface

SYNOPSIS

       bind #H[drive] /dev
       bind #w[target[.lun]] /dev

       /dev/hd0disk
       /dev/hd0partition
       /dev/sd0disk
       /dev/sd0partition
	...

DESCRIPTION

       The  hard  disk interfaces (wren, #w, is a SCSI disk; ata, #H, is an IDE or ATA disk) serve a one-level directory giving access to the hard
       disk partitions.  The parameter to attach defines the numerical SCSI target and logical unit number or the  IDE	drive  number  to  access.
       Both default to zero.

       Each  partition name is prefixed by hd and the numeric drive identifier.  The partition always exists and covers the entire disk.  The size
       of each partition as reported by stat(2) is the number of bytes in the partition, so the size of is the size of the entire disk.

       The partition also always exists; it is the last block on the disk for SCSI, second to last for IDE.  If it contains valid partition  data,
       those  partitions will be visible as well.  Every time the device is bound, the partitions are updated to reflect any changes in the parti-
       tion file.

       The format of the partition file is the string

	      plan9 partitions

       on a line, followed by partition specifications, one per line, consisting of a name and textual strings for the block start and	limit  for
       each partition on the disk.

       The program prep(8) writes the partition table for the disk; its use is preferred to writing it by hand.

SEE ALSO

       prep(8), scsi(3)

SOURCE

       /sys/src/9/port/devwren.c
       /sys/src/9/pc/devata.c

																	   WREN(3)