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 difference 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 considered experimental.