RUMP_TMPFS(8)

NAME
rump_tmpfs - mount the tmpfs file system using a userspace server

SYNOPSIS
file-system PUFFS
pseudo-device putter

rump_tmpfs [options] special node

DESCRIPTION
The rump_tmpfs utility can be used to mount tmpfs file systems. It uses rump(3) and p2k(3) to facilitate running the file system as a server in userspace. As opposed to mount_tmpfs(8), rump_tmpfs 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_tmpfs 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_tmpfs instead of mount_tmpfs(8). Corrupt file system images commonly cause the file system to crash the entire kernel, but with rump_tmpfs only the userspace server process will dump core.

To use rump_tmpfs via mount(8), the flags -o rump and -t tmpfs should be given. Similarly, rump_tmpfs is run instead of mount_tmpfs(8) if “rump” is added to the options field of fstab(5).

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

SEE ALSO
p2k(3), puffs(3), rump(3), mount_tmpfs(8)

HISTORY
The rump_tmpfs utility first appeared in NetBSD 5.0. It is currently considered experimental.