NAME
rump_server,
rump_allserver —
rump kernel server
SYNOPSIS
rump_server |
[-sv]
[-c ncpu]
[-d
drivespec]
[-l
library]
[-m
module]
[-r
total_ram] url |
DESCRIPTION
The
rump_server utility is used to provide a rump kernel
service. Clients can use the system calls provided by
rump_server via
url.
The difference between
rump_server and
rump_allserver is that
rump_server offers
only a minimalistic set of features, while
rump_allserver
provides all rump kernel components which were available when the system was
built. At execution time it is possible to load components from the command
line as described in the options section.
-
-
- -c
ncpu
- Configure ncpu virtual CPUs on
SMP-capable archs. By default, the number of CPUs equals the number of
CPUs on the host.
-
-
- -d
drivespec
- The argument drivespec maps a host
file in the rump kernel fs namespace. The string
drivespec must be of comma-separated
“name=value” format and must contain the following tokens:
-
-
- key
- Block device path in rump kernel namespace. This must
be specified according to the rules for a key in
rump_etfs(3).
-
-
- hostpath
- Host file used for storage. If the file does not exist,
it will be created.
-
-
- size
- Size of the mapping. Similar to
dd(1), this argument accepts
a suffix as the multiplier for the number. The special value
“host” indicates that the current size of
hostpath will be used. In this case it is
assumed that hostpath exists and is a regular
file.
-
-
- OR
-
- disklabel
- Use a disklabel partition identifier to specify the
offset and size of the mapping. hostpath must
contain an existing and valid disklabel within the first 64k.
The following are optional:
-
-
- offset
- Offset of the mapping. The window into
hostpath therefore is
[offset, offset+size]. In
case this parameter is not given, the default value 0 is used.
-
-
- type
- The type of file that key is
exposed as within the rump kernel. The possibilities are
“blk”, “chr”, and “reg” for block
device, character device and regular file, respectively. The default
is a block device.
Note: the contents of block devices are cached in the rump kernel's
buffer cache. To avoid cache incoherency, it is advisable not to
access a file through the host namespace while it is mapped as a block
device in a rump kernel.
In case hostpath does not exist, it will be created as
a regular file with mode 0644 (plus any restrictions placed by umask). In
case hostpath is a regular file and is not large
enough to accommodate the specified size, it will be extended to the
specified size.
-
-
- -l
library
- Call dlopen() on library before
initializing the rump kernel. In case library
provides a kernel module, it will appear as a builtin module in the rump
kernel. Any rump kernel component present in library
will also be initialized.
The argument library can contain a full path or a
filename, in which case the standard dynamic library search path will be
used. By default, lazy resolution is used, and may result in a runtime
error due to missing components. To test a configuration, run
rump_server with
LD_BIND_NOW=1
(see examples).
-
-
- -m
module
- Load and link a kernel module after the rump kernel is
initialized. For this to work, the rump kernel must include the vfs
faction, since the module is loaded using kernel vfs code (see
EXAMPLES).
-
-
- -r
total_ram
- Sets the limit of kernel memory allocatable by the server
to total_ram as opposed to the default which allows
the server to allocate as much memory as the host will give it. This
parameter is especially useful for VFS servers, since by default the
virtual file system will attempt to consume as much memory as it can, and
accessing large files can cause an excessive amount of memory to be used
as file system cache.
-
-
- -s
- Do not detach from the terminal. By default,
rump_server detaches from the terminal once the service
is running on url.
-
-
- -v
- Set bootverbose.
After use,
rump_server can be made to exit using
rump.halt(1).
EXAMPLES
Start a server and load the tmpfs file system module, and halt the server
immediately afterwards:
$ rump_server -lrumpvfs -m /modules/tmpfs.kmod unix://sock
$ env RUMP_SERVER=unix://sock rump.halt
Start a server with the one gigabyte host file
dk.img mapped
as the block device
/dev/dk in the rump kernel.
$ rump_allserver -d key=/dev/dk,hostpath=dk.img,size=1g unix://sock
Start a server which listens on INADDR_ANY port 3755
$ rump_server tcp://0:3755/
Test that a configuration contains all of the necessary components:
$ env LD_BIND_NOW=1 rump_server -lrumpvfs -lrumpfs_ffs unix://tsock
Start a FFS server with a 16MB kernel memory limit.
$ rump_server -lrumpfs_ffs [...] -r 16m unix://ffs
SEE ALSO
rump.halt(1),
dlopen(3),
rump(3),
rump_sp(7)