display system data
pstat displays open file entry, swap space
utilization, terminal state, and vnode data structure information. If
core is given, the information is sought there,
otherwise in the running kernel via /dev/kmem. The
required namelist is taken from the running kernel unless
system is specified.
The options are as follows:
-dformat symbol ...
- Print the values of symbol using the specified
format. format is a
printf(3)-style format, without the leading percent or precision
specifiers, such as s, p, or
llx. Symbol names are read from the remaining
command line arguments. Addresses may also be specified in hex.
-doption requires the ability to open /dev/kmem which may be restricted based upon the value of the kern.allowkmem sysctl(8).
- Print the open file table with these headings:
- The core location of this table entry.
- The type of object the file table entry points to.
- Miscellaneous state variables encoded thus:
- open for reading
- open for writing
- open for appending
- exclusive or shared lock present
- signal pgrp when data ready
- Number of processes that know this open file.
- Number of messages outstanding for this file.
- The location of the vnode table entry or socket structure for this file.
- The file offset (see lseek(2)). This information is only visible to the user or superuser.
- Use 1K-byte blocks.
- Extract values associated with the name list from the specified core instead of the running kernel.
- Extract the name list from the specified system instead of the running kernel.
- Print devices by major/minor number rather than by name.
- Print information about swap space usage on all the swap areas compiled
into the kernel. The first column is the device name of the partition. The
next column is the total space available in the partition. The
Used column indicates the total blocks used so far;
the Available column indicates how much space is
remaining on each partition. The Capacity reports
the percentage of space used.
If more than one partition is configured into the system, totals for all of the statistics will be reported in the final line of the report.
- Prints the number of used and free slots for open files, used vnodes, and swap space. It is useful for checking to see how large system tables become if the system is under heavy load.
- Print table for terminals with these headings:
- Physical device name.
- Number of characters in raw input queue.
- Number of characters in canonicalized input queue.
- Number of characters in output queue.
- High water mark for output.
- Low water mark for output.
- Calculated column position of terminal.
- Miscellaneous state variables encoded thus:
- waiting for open to complete
- carrier is on
- delay timeout in progress
- outq has been flushed during DMA
- busy doing output
- process is awaiting output
- open for exclusive use
- output stopped
- further input blocked
- tty in async I/O mode
- next character is escaped lowercase special
- printing erase sequence
- next character is literal
- retyping suspended input
- counting tab width, ignoring output flush
- Enclosing session.
- Process group for which this is controlling terminal.
- Line discipline: ‘
term’ for TTYDISC (see termios(4)), ‘
ppp’ for PPPDISC (see ppp(4)) and ‘
nmea’ for NMEADISC (see nmea(4)).
- Print the active vnodes. Each group of vnodes corresponding to a
particular filesystem is preceded by a two line header. The first line
consists of the following:
*** MOUNT fstype from on on fsflags
where fstype is one of the file systems supported by the kernel; from is the partition the filesystem is mounted from; on is the directory the filesystem is mounted on; and fsflags is a list of optional flags applied to the mount (see mount(8)). The second line is a header for the individual fields, the first part of which are fixed, and the second part are filesystem type specific. The headers common to all vnodes are:
- Location of this vnode.
- File type.
- A list of letters representing vnode flags:
- VROOT root of its file system.
- VTEXT pure text prototype.
- VSYSTEM vnode being used by kernel.
- VISTTY vnode represents a tty.
- VXLOCK locked to change underlying type.
- VXWANT process is waiting for vnode.
- VBWAIT waiting for output to complete.
- VALIASED vnode has an alias.
- VONFREELIST vnode is on a free list.
- VLOCKSWORK FS supports locking discipline.
- VONSYNCLIST vnode is on syncer worklist.
- The number of references to this vnode.
- The number of I/O buffers held by this vnode.
- The vnode fileid. In the case of ffs this is the inode number.
- Miscellaneous filesystem specific state variables encoded thus:
- For ffs:
- access time must be corrected
- changed time must be corrected
- modification time must be corrected
- has a rename in progress
- contains modifications
- contains lazy modifications
- shared lock applied
- exclusive lock applied
- For nfs:
- waiting for I/O buffer flush to complete
- I/O buffers being flushed
- locally modified data exists
- an earlier write failed
- non-cacheable lease (nqnfs)
- write lease (nqnfs)
- lease was evicted (nqnfs)
- special file accessed
- special file updated
- special file times changed
- Number of bytes in an ordinary file, or major and minor device of special file.
-voption requires the ability to open /dev/kmem which may be restricted based upon the value of the kern.allowkmem sysctl(8).
- If the environment variable
BLOCKSIZEis set, and the
-koption is not specified, the block counts will be displayed in units of that size block.
fstat(1), netstat(1), procmap(1), ps(1), systat(1), tcpbench(1), top(1), stat(2), printf(3), fs(5), iostat(8), vmstat(8)
Ken Thompson, UNIX Implementation, Bell System Technical Journal, Number 6, Volume 57, pp. 1931–1946, 1978.
pstat command appeared in
Version 7 AT&T UNIX.
Swap statistics are reported for all swap partitions compiled into the kernel, regardless of whether those partitions are being used.
Does not understand NFS swap servers.