NAME
snap, snapfs – create and mount process snapshots |
SYNOPSIS
snap [ –o file ] pid...
snapfs [ –a ] [ –m mtpt ] [ –s service ] file... |
DESCRIPTION
Snap and snapfs allow one to save and restore (static) process
images, usually for debugging on a different machine or at a different
time. Snap writes a snapshot (see snap(6)) of the named processes to file (default standard output). If pid is a text string rather than a process id, snap will save all processes with that name that are owned by the current user. Both memory and text images are saved.
Snapfs is a file server that recreates the /proc directories for
the processes in the snapshot. By default, it mounts the new directories
into /proc before the current entries. The –m option can be used
to specify an alternate mountpoint, while –a will cause it to mount
the new directories after the current entries. The
–s option causes it to serve requests via /srv/service. |
EXAMPLE
Suppose page has hung viewing Postscript on your terminal, but
the author is gone for the rest of the month and you want to make
sure the process is still around for debugging on his return.
You can save the errant processes with
|
SOURCE
/sys/src/cmd/snap |
SEE ALSO
acid(1), db(1), proc(3), snap(6) |
BUGS
The snapshots take up about as much disk space as the processes
they contain did memory. Compressing them when not in use is recommended,
as is storing them on a rewritable disk.
Pid as a non–numeric string is unimplemented; it has to be a number. |