NAME

rump_server, rump_allserver — rump kernel server

SYNOPSIS

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.

The type of file that key is exposed as within the rump kernel is specified with:

type

Possible values are ‘blk’, ‘chr’, and ‘reg’ for block device, character device and regular file, respectively. The default is a block device (‘blk’).

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.

For block and character devices the [offset, offset+size] region of the file must be specified with:

disklabel

Use a disklabel partition letter to specify the offset and size of the mapping. hostpath must contain a valid disklabel within the first 64k.

offset

Offset of the mapping. The default is 0.

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.

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(3) 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 AB_VERBOSE in rump kernel's boothowto(9).

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.

Start a server which listens on INADDR_ANY port 3755

Test that a configuration contains all of the necessary components:

Start a FFS server with a 16MB kernel memory limit.

SEE ALSO

rump.halt(1), dlopen(3), rump(3), rump_etfs(3), rump_sp(7)