MirOS Manual: vnconfig(8)

VNCONFIG(8)              BSD System Manager's Manual               VNCONFIG(8)

NAME

     vnconfig - configure vnode disks for file swapping or pseudo file systems

SYNOPSIS

     vnconfig [-c] [-vkr] [-f keyfile] rawdev regular_file
     vnconfig -u [-v] rawdev
     vnconfig -l [rawdev]
     vnconfig -K algorithm -f keyfile

DESCRIPTION

     The vnconfig command configures vnode pseudo disk devices. It will asso-
     ciate (or disassociate) the special file rawdev with the regular file
     regular_file allowing the latter to be accessed as though it were a disk.
     Hence a regular file within the filesystem can be used for swapping or
     can contain a filesystem that is mounted in the name space. Both tradi-
     tional devices, vnd, and the cache-coherent devices, svnd, are configured
     through vnconfig.

     If you read the regular file while using svnd, you need to mount the svnd
     with the mount option sync to ensure consistency in the buffer cache. For
     normal operation this is not necessary.

     The options are as follows:

     -c      Configures the device. If successful, references to rawdev will
             access the contents of regular_file. This is the default opera-
             tion.

     -f keyfile
             Instead of an encryption key read from stdin, an ASN.1 octet
             string will be decoded from the PEM format keyfile. This option
             implies -k.

     -k      Associate an encryption key with the device. All data will be en-
             crypted using the Blowfish cipher before it is written to the
             disk. Encryption only works with svnd.

     -K algorithm
             Generate a PEM format keyfile containing an encrypted ASN.1 octet
             string which can be used as keyfile for further invocations of
             vnconfig -kf. The ASN.1 octet string contains 448 random bits
             gained from use of arc4random(3) unless the -k option is given,
             in which case the old key will be asked for twice first and then
             written (as PEM encoded ASN.1 octet string, encrypted) into the
             file in order to assist transitioning. In that case, you will be
             asked first for the old key twice, then for the new PEM
             passphrase twice. The algorithm can be chosen from the default
             openssltool(1) list.

     -l      List the vnd devices and indicate which ones are in use. If a
             specific rawdev is given, then only that one will be described.

     -r      If the kernel supports it, don't write to the underlying file.
             This is supported since MirOS #7.

     -u      Unconfigures the device.

     -v      Print messages to stdout describing actions taken.

     If no action option is given, -c is assumed.

FILES

     /dev/{,r}{,s}vnd*

EXAMPLES

     Configure the vnode disk svnd0 (all of its partitions become usable):

           # vnconfig svnd0 /tmp/diskimage

     Unconfigure the same device:

           # vnconfig -u svnd0

     Show a list of supported Cipher Types:

           $ openssl enc -

SEE ALSO

     openssl(1), openssltool(1), arc4random(3), blowfish(3), vnd(4), mount(8),
     swapon(8), umount(8)

HISTORY

     Support for external keyfiles was added in MirOS #9.

BUGS

     This command should really be named vndconfig.

MirOS BSD #10-current            July 8, 1993                                1

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