rump_ffs(8) - NetBSD Manual Pages

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


NAME

     rump_ffs -- mount the ffs file system using a userspace server


SYNOPSIS

     file-system PUFFS
     pseudo-device putter

     rump_ffs [options] special node


DESCRIPTION

     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 (starting from 10% and
     depending on the workload and file system in question), there is no dif-
     ference to using in-kernel code.

     In case mounting a file system image from a regular file, rump_ffs does
     not require the use of vnconfig(8) unlike kernel file systems.  Instead,
     the image path can be directly passed as the special file path.  The
     exception is if the image contains a disklabel.  In this case vnconfig is
     required to resolve the start offset for the correct partition within the
     image.

     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 run instead of mount_ffs(8) if ``rump'' is
     added to the options field of fstab(5).

     Please see mount_ffs(8) for a full description of the available command
     line options.


SEE ALSO

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


HISTORY

     The rump_ffs utility first appeared in NetBSD 5.0.  It is currently con-
     sidered experimental.

NetBSD 5.1                     February 15, 2009                    NetBSD 5.1