FS(8) FS(8)
NAME
fs, exsort - file server maintenance
SYNOPSIS
help [ command ... ]
arp subcommand
cfs filesystem
check [options]
clri [file...]
cpu [proc]
create path uid gid perm [lad]
cwcmd subcommand
date [[+-] seconds]
duallow [uid]
dump
files
flag flag [ channel ]
fstat [ files ]
halt
hangup channel
newuser name [options]
noattach
passwd
profile [01]
remove [files...]
route subcommand
stat[adesw]
stats [[-] flags...]
sync
time command
trace [number]
users [file]
version
who [user...]
wormeject [ tunit ]
wormingest [ tunit ]
disk/exsort [-w] [file]
DESCRIPTION
Except for exsort, these commands are available only on the
console of an fs(4) file server.
The console requires the machine's password to be supplied
before accepting commands. Typing a control-D will cause
the server to request the password again.
Help prints a `usage string' for the named commands, by
default all commands. Also, many commands print menus of
their options if given incorrect or incomplete parameters.
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Arp has two subcommands: print prints the contents of the
ARP cache and flush flushes it.
Cfs changes the current file system, that is, the file tree
to which commands (check, clri, create, newuser, profile,
remove, and users) apply. The initial filesystem is main.
Check verifies the consistency of the current file system.
With no options it checks and reports the status. It sus-
pends service while running. Options are:
rdall Read every block in the file system (can take a long
time). Normally, check will stop short of the actual
contents of a file and just verify the block
addresses.
tag Fix bad tags; each block has a tag that acts as a
backwards pointer for consistency checking.
ream Fix bad tags and also clear the contents of blocks
that have bad tags.
pfile Print every file name.
pdir Print every directory name.
free Rebuild the list of free blocks with all blocks that
are not referenced. This option is only useful on
non-cache/WORM file systems.
bad Each block address that is out of range or duplicate
is cleared. Note that only the second and subsequent
use of a block is cleared. Often the problems in a
file system are caused by one bad file that has a lot
of garbage block addresses. In such a case, it is
wiser to use check to find the bad file (by number of
diagnostic messages) and then use clri to clear the
addresses in that file. After that, check can be
used to reclaim the free list.
touch Cause every directory and indirect block not on the
current WORM disk to be advanced to the current WORM
on the next dump. This is a discredited idea to try
to keep operating on the knee of the cache working
set. Buy more cache disk.
Clri clears the internal directory entry and abandons stor-
age associated with files. It ignores the usual rules for
sanity, such as checking against removing a non-empty direc-
tory. A subsequent check free will place the abandoned
storage in the free list.
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Cpu prints the CPU utilization and state of the processes in
the file server. If the name of a process type argument is
given, then CPU utilization for only those processes is
printed.
Create creates a file on the current file system. Uid and
gid are names or numbers from /adm/users. Perm is the low 9
bits of the permission mode of the file, in octal. An
optional final l, a, or d creates a locked file, append-only
file, or directory.
Cwcmd controls the cached WORM file systems. The subcom-
mands are:
mvstate state1 state2 [platter]
States are none, dirty, dump, dump1, error, read, and
write. A mvstate dump1 dump will cause I/O errors in
the last dump to be retried. A mvstate dump1 write
will cause I/O errors in the last dump to be retried in
reallocated slots in the next dump. A mvstate read
none will flush the cache associated with the WORM. A
mvstate dump write aborts the background process dump-
ing to WORM; as a consequence it leaves holes in the
dump file system. Other uses are possible but arcane.
The optional platter limits affected blocks to those on
that platter.
prchain [start] [back]
Print the chain of superblocks for the directory con-
taining the roots of the dumped file systems, starting
at block number start (default 0) going forward (back-
wards if back is supplied).
savecache [percent]
Copy the block numbers, in native endian longwords, of
blocks in the read state to the file /adm/cache for use
by disk/exsort. If an argument is given, then that
percent (most recently used) of each cache bucket is
copied.
loadcache [dskno]
Read /adm/cache and for every block there on WORM disk
dskno, read the block from WORM to the cache. If dskno
is not supplied, all blocks in /adm/cache are read.
startdump [01]
Suspend (0) or restart (1) the background dump process.
touchsb
Verify that the superblock on the WORM is readable,
ignoring the cached copy.
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acct Prints how many times each user has caused the system
to allocate new space on the WORM; the units are mega-
bytes.
clearacct
Clears the accounting records for acct.
Date prints the current date. It may be adjusted using
+-seconds. With no sign, it sets the date to the absolute
number of seconds since 00:00 Jan 1, 1970 GMT; with a sign
it trims the current time.
Duallow sets permissions such that the named user can read
and search any directories. This is the permission neces-
sary to do a du(1) command anywhere in the file system to
discover disk usage.
Dump starts a dump to WORM immediately for all file systems
that have a WORM associated. File service is suspended
while the cache is scanned; service resumes when the copy to
WORM starts.
Files prints for every connection the number of allocated
fids.
Fstat prints the current status of each named file, includ-
ing uid, gid, wuid (uid of the last user to modify the
file), size, qid, and disk addresses.
Flag toggles flags, initially all off:
arp Report ARP activity.
attach Report as connections are made to the file server.
chat (Very noisy.) Print all 9P messages to and from
the server.
route Report received RIP packets.
ro Report I/O on the WORM device.
If given a second numeric channel argument, as reported by
who, the flag is altered only on that connection.
Halt does a sync and halts the machine, returning to the
boot ROM.
Hangup clunks all the fids on the named channel, which has
the same format as in the output of the who command.
Newuser requires a name argument. With no options it adds
user name, with group leader name, to /adm/users and makes
the directory /usr/name owned by user and group name. The
options are
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? Print the entry for name.
: Add a group: add the name to /adm/users but don't
create the directory. By convention, groups are
numbered starting from 10000, users from 0.
newname Rename existing user name to newname.
=leader Change the leader of name to leader. If leader is
missing, remove the existing leader.
+member Add member to the member list of name.
-member Remove existing member from the member list of
name.
After a successful newuser command the file server over-
writes /adm/users to reflect the internal state of the user
table.
Noattach disables attach(5) messages, in particular for sys-
tem maintenance. Previously attached connections are unaf-
fected. Another noattach will enable normal behavior.
Passwd sets the machine's password and writes it in non-
volatile RAM.
Profile 0 clears the profiling buffer and enables profiling;
profile 1 stops profiling and writes the data to
/adm/kprofdata for use by kprof (see prof(1)). If a number
is not specified, the profiling state toggles.
Remove removes files.
Route maintains an IP routing table. The subcommands are:
add dest gate [mask]
Add a static route from IP address dest
using gateway gate with an optional sub-
net mask.
delete dest Delete an entry from the routing table.
print Display the contents of the routing
table.
ripon Enables the table to be filled from RIP
packets.
ripoff Disables the table from being updated by
RIP packets.
The stat commands are connected with a service or device
identified by the last character of the name: d, SCSI tar-
gets; e, Ethernet controllers; w, cached WORM. The stata
command prints overall statistics about the file system.
The stats command takes an optional argument identifying the
characters of stat commands to run. The option is remem-
bered and becomes the default for subsequent stats commands
if it begins with a minus sign.
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Sync writes dirty blocks in memory to the magnetic disk
cache.
Time reports the time required to execute the command.
Trace with no options prints the set of queue-locks held by
each process in the file server. If things are quiescent,
there should be no output. With an argument number it
prints a stack traceback of that process.
Users uses the contents of file (default /adm/users) to ini-
tialize the file server's internal representation of the
users structure. Incorrectly formatted entries in file will
be ignored. If file is explicitly default, the system
builds a minimal functional users table internally; this can
help recover from disasters. If the file cannot be read,
you must run
users default
for the system to function. The default table looks like
this:
-1:adm:adm:
0:none:adm:
1:tor:tor:
10000:sys::
10001:map:map:
10002:doc::
10003:upas:upas:
10004:font::
10005:bootes:bootes:
Version reports when the file server was last compiled and
last rebooted.
Who reports, one per line, the names of users connected to
the file server and the status of their connections. The
first number printed on each line is the channel number of
the connection. If users are given the output selects con-
nections owned by those users.
Wormeject moves the WORM disk in slot tunit to the output
shelf.
Wormingest moves the WORM disk from the input shelf to slot
tunit.
When the file server boots, it prints the message
for config mode hit a key within 5 seconds
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If a character is typed within 5 seconds of the message
appearing, the server will enter config mode. See
fsconfig(8) for the commands available in config mode. The
system also enters config mode if, at boot time, the non-
volatile RAM does not appear to contain a valid configura-
tion.
Exsort is a regular command to be run on a CPU server, not
on the file server console. It reads the named file
(default /adm/cache) and sorts the cache disk block numbers
contained therein. It assumes the numbers are 4-byte inte-
gers and guesses the endianness by looking at the data. It
then prints statistics about the cache. With option -w it
writes the sorted data back to file.
SOURCE
/sys/src/fs
/sys/src/cmd/disk/exsort.c
SEE ALSO
fs(4)
Ken Thompson, ``The Plan 9 File Server''.
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