rump_ffs(8) - NetBSD Manual Pages

RUMP_FFS(8)             NetBSD System Manager's Manual             RUMP_FFS(8)


NAME

     rump_ffs -- mount a ffs image with a userspace server


SYNOPSIS

     file-system PUFFS
     pseudo-device putter

     rump_ffs [options] image mountpoint


DESCRIPTION

     NOTE! This manual page describes features specific to the rump(3) file
     server.  Please see mount_ffs(8) for a full description of the available
     command line options.

     The rump_ffs utility can be used to mount ffs file systems.  It uses
     rump(3) and p2k(3) to facilitate running the file system as a server in
     userspace.  As opposed to mount_ffs(8), rump_ffs does not use file system
     code within the kernel and therefore does not require kernel support
     except puffs(4).  Apart from a minor speed penalty there is no downside
     with respect to in-kernel code.

     rump_ffs does not require using vnconfig(8) for mounts from regular files
     and the file path can be passed directly as the image parameter.  In
     fact, the use of vnconfig(8) is discouraged, since it is unable to prop-
     erly deal with images on sparse files.

     In case the image contains multiple partitions, the desired partition
     must be indicated by appending the token ``%DISKLABEL:p%'' to the image
     path.  The letter ``p'' specifies the partition as obtained via
     disklabel(8).  For example, to mount partition ``e'' from image
     /tmp/wd0.img, use ``/tmp/wd0.img%DISKLABEL:e%''.

     It is recommended that untrusted file system images be mounted with
     rump_ffs instead of mount_ffs(8).  Corrupt file system images commonly
     cause the file system to crash the entire kernel, but with rump_ffs only
     the userspace server process will dump core.

     To use rump_ffs via mount(8), the flags -o rump and -t ffs should be
     given.  Similarly, rump_ffs is used instead of mount_ffs(8) if ``rump''
     is added to the options field of fstab(5).


SEE ALSO

     p2k(3), puffs(3), rump(3), mount_ffs(8)


HISTORY

     The rump_ffs utility first appeared in NetBSD 5.0.

NetBSD 10.99                   November 21, 2010                  NetBSD 10.99