NAME

       rapiddisk - An administration tool to manage the RapidDisk RAM disk devices and RapidDisk-
       Cache mappings.

SYNOPSIS

       rapiddisk [ -h | -v ] function [ parameters ]

DESCRIPTION

       rapiddisk is a RapidDisk module management tool to  manage  RapidDisk  RAM  disk  devices.
       Dynamically  create,  remove,  resize  RAM  volumes and if desired, map or unmap them as a
       cache volume to any block device. Access those drives  locally  or  export  those  volumes
       across an NVMe Target network.

   Options
       -h     Invoke the help menu.

       -v     Display the version number.

   Functions
       -a     Attach RAM disk device (size in MBytes).

       -b     Backend block device absolute path (for cache mapping).

       -c     Input capacity for size or resize of RAM disk device (in MBytes).

       -d     Detach RAM disk device.

       -e     Export a RapidDisk block device as an NVMe Target.

       -f     Erase all data to a specified RapidDisk device (dangerous).

       -g     Do not print header.

       -H     The host to export / unexport the NVMe Target to / from.

       -i     Define  the  network  interface  to enable for NVMe Target exporting. Port must not
              already exist and interface must not be already enabled.

       -j     Enable JSON formatted output.

       -L     Lock a RapidDisk block device (set to read-only).

       -l     List all attached RAM disk devices.

       -m     Map an RapidDisk device as a caching node to another block device.

       -N     List only enabled NVMe Target ports.

       -n     List RapidDisk enabled NVMe Target exports.

       -P     The port to export / unexport the NVMe Target to / from.

       -p     Define cache policy:  write-through  (wt),  write-around  (wa)  or  writeback  (wb)
              (dangerous)  (default:  write-through).   Writeback  caching is supplied by the dm-
              writecache kernel module and is not intended for production use as it may result in
              data loss on hardware/power failure.

       -q     List all system memory and block device resources.

       -R     Revalidate size of NVMe export using existing RapidDisk device.

       -r     Dynamically grow the size of an existing RapidDisk device.

       -s     Obtain RapidDisk-Cache Mappings statistics.

       -t     Define the NVMe Target port's transfer protocol (i.e. tcp or rdma).

       -U     Unlock a RapidDisk block device (set to read-write).

       -u     Unmap a RapidDisk device from another block device.

       -X     Remove the NVMe Target port (must be unused).

       -x     Unexport  a RapidDisk block device from an NVMe Target. To remove export to host or
              port, only define the host and / or port. Not defining a host or port  will  result
              in the block device being removed from the NVMe Target subsystem.

   Parameters (if applicable)
       [size] Specify desired size of attaching RAM disk device in MBytes.

       [mode] Write Through (wt) or Write Around (wa) for cache.

EXAMPLE USAGE

       rapiddisk -l

       rapiddisk -l -j

       rapiddisk -a 64

       rapiddisk -d rd2

       rapiddisk -r rd2 -c 128

       rapiddisk -m rd1 -b /dev/sdb

       rapiddisk -m rd1 -b /dev/sdb -p wt

       rapiddisk -m rd3 -b /dev/mapper/rc-wa_sdb -p wb

       rapiddisk -u rc-wt_sdb

       rapiddisk -s rc-wt_sdb

       rapiddisk -f rd2

       rapiddisk -L rd2

       rapiddisk -U rd3

       rapiddisk -i eth0 -P 1 -t tcp

       rapiddisk -X -P 1

       rapiddisk -e -b rd3 -P 1 -H nqn.host1

       rapiddisk -R -b rd0

       rapiddisk -x -b rd3 -P 1 -H nqn.host1

MANAGING RAPIDDISK AS AN NVME TARGET

       There  are  a  few things that need to be known when using the NVMe Target features of the
       RapidDisk suite.

       1.     In order to map any RapidDisk device and export it in the  NVMe  Target  framework,
              the nvmet and the nvmet-tcp or nvmet-rdma kernel modules must be inserted.

       2.     At  least  one  Ethernet  interface  will need to be configured as a target port to
              export the RapidDisk volume from.

              ex) rapiddisk -i eth -P 1 -t tcp

       3.     When exporting a volume, a RapidDisk volume and a target port must be defined. If a
              host NQN is not defined, the administration utility will provide access to any host
              NQN. Note - a target can be exported across more than one target port.

              ex) rapiddisk -e -b rd3 -P 1

              If a host NQN is defined, access is restricted to only those host NQNs. Note -  the
              following  command  example  can  be repeated multiple times to add additional host
              NQNs for the specified target export.

              ex) rapiddisk -e -b rd3 -P 1 -H nqn.host1

       4.     Unexporting RapidDisk volumes looks a bit different than exporting. If a  host  NQN
              is defined for a specified target, only that NQN will be removed from accessing the
              exported target.

              ex) rapiddisk -x -b rd3 -H nqn.host1

              Removing all allowed host NQNs  will  revert  access  to  any  and  all  host  NQNs
              requesting access to the target.

              If  a  target  port  is  defined, the exported target will not be exported from the
              interface if one condition is met: the target has no defined allowed host NQNs.

              ex) rapiddisk -x -b rd3 -P 1 -H nqn.host1

              ex) rapiddisk -x -b rd3 -P 1

              And if there are no defined allowed host NQNs and the target is not being  exported
              across any target ports, the entire target is removed from the subsystem.

EXIT STATUS

       rapiddisk returns a zero exit status if no error occurs during operation. A non-zero value
       is returned on error.

AUTHORS

       Original version: Petros Koutoupis (petros@petroskoutoupis.com)

SEE ALSO

       View the RapidDisk project page: http://www.rapiddisk.org