NAME¶

ssm - System Storage Manager: a single tool to manage your storage

SYNOPSIS¶

ssm [-h] [--version] [-v] [-f] [-b BACKEND] {check,resize,create,list,add,remove,snapshot} ... ssm create [-h] [-s SIZE] [-n NAME] [--fstype FSTYPE] [ -r LEVEL] [-I STRIPESIZE] [-i STRIPES] [ -p POOL] [device [device ...]] [mount] ssm list [-h] [{volumes,vol,dev,devices,pool,pools,fs,filesystems,snap,snapshots}] ssm remove [-h] [-a] [items [items ...]] ssm resize [-h] [-s SIZE] volume [device [ device ...]] ssm check [-h] device [device ...] ssm snapshot [-h] [-s SIZE] [-d DEST | -n NAME] volume ssm add [-h] [-p POOL] device [device ...]

DESCRIPTION¶

System Storage Manager provides easy to use command line interface to manage your storage using various technologies like lvm, btrfs, encrypted volumes and more. In more sophisticated enterprise storage environments, management with Device Mapper (dm), Logical Volume Manager (LVM), or Multiple Devices (md) is becoming increasingly more difficult. With file systems added to the mix, the number of tools needed to configure and manage storage has grown so large that it is simply not user friendly. With so many options for a system administrator to consider, the opportunity for errors and problems is large. The btrfs administration tools have shown us that storage management can be simplified, and we are working to bring that ease of use to Linux filesystems in general.

OPTIONS¶

SYSTEM STORAGE MANAGER COMMANDS¶

Introduction¶

System Storage Manager have several commands you can specify on the command line as a first argument to the ssm. They all have specific use and its own arguments, but global ssm arguments are propagated to all commands.

Create command¶

ssm create [-h] [-s SIZE] [-n NAME] [--fstype FSTYPE] [ -r LEVEL] [-I STRIPESIZE] [-i STRIPES] [ -p POOL] [device [device ...]] [mount] This command creates a new volume with defined parameters. If device is provided it will be used to create a volume, hence it will be added into the pool prior the volume creation (See Add command section). More devices can be used to create a volume. If the device is already used in the different pool, then ssm will ask you whether you want to remove it from the original pool. If you decline, or the removal fails, then the volume creation fails if the SIZE was not provided. On the other hand, if the SIZE is provided and some devices can not be added to the pool the volume creation might succeed if there is enough space in the pool. POOL name can be specified as well. If the pool exists new volume will be created from that pool (optionally adding device into the pool). However if the POOL does not exist ssm will attempt to create a new pool with provided device and then create a new volume from this pool. If --backend argument is omitted, the default ssm backend will be used. Default backend is lvm. ssm also supports creating RAID configuration, however some back-ends might not support all the levels, or it might not support RAID at all. In this case, volume creation will fail. If mount point is provided ssm will attempt to mount the volume after it is created. However it will fail if mountable file system is not present on the volume.

List command¶

ssm list [-h] [{volumes,vol,dev,devices,pool,pools,fs,filesystems,snap,snapshots}] List informations about all detected devices, pools, volumes and snapshots found in the system. list command can be used either alone to list all the information, or you can request specific section only. Following sections can be specified:

Remove command¶

ssm remove [-h] [-a] [items [items ...]] This command removes item from the system. Multiple items can be specified. If the item can not be removed for some reason, it will be skipped. item can represent:

Resize command¶

ssm resize [-h] [-s SIZE] volume [device [ device ...]] Change size of the volume and file system. If there is no file system only the volume itself will be resized. You can specify device to add into the volume pool prior the resize. Note that device will only be added into the pool if the volume size is going to grow. If the device is already used in the different pool, then ssm will ask you whether you want to remove it from the original pool. In some cases file system has to be mounted in order to resize. This will be handled by ssm automatically by mounting the volume temporarily.

Check command¶

ssm check [-h] device [device ...] Check the file system consistency on the volume. You can specify multiple volumes to check. If there is no file system on the volume, this volume will be skipped. In some cases file system has to be mounted in order to check the file system This will be handled by ssm automatically by mounting the volume temporarily.

Snapshot command¶

ssm snapshot [-h] [-s SIZE] [-d DEST | -n NAME] volume Take a snapshot of existing volume. This operation will fail if back-end which the volume belongs to does not support snapshotting. Note that you can not specify both NAME and DESC since those options are mutually exclusive. In some cases file system has to be mounted in order to take a snapshot of the volume. This will be handled by ssm automatically by mounting the volume temporarily.

Add command¶

ssm add [-h] [-p POOL] device [device ...] This command adds device into the pool. The device will not be added if it's already part of different pool. When multiple devices are provided, all of them are added into the pool. If one of the devices can not be added into the pool for some reason, it will be skipped. If no pool is specified, default pool will be chosen. In the case of non existing pool, it will be created using provided devices.

BACK-ENDS¶

Introduction¶

Ssm aims to create unified user interface for various technologies like Device Mapper (dm), Btrfs file system, Multiple Devices (md) and possibly more. In order to do so we have a core abstraction layer in ssmlib/main.py. This abstraction layer should ideally know nothing about the underlying technology, but rather comply with device, pool and volume abstraction. Various backends can be registered in ssmlib/main.py in order to handle specific storage technology implementing methods like create, snapshot, or remove volumes and pools. The core will then call these methods to manage the storage without needing to know what lies underneath it. There are already several backends registered in ssm.

Btrfs backend¶

Btrfs is the file system with many advanced features including volume management. This is the reason why btrfs is handled differently than other conventional file systems in ssm. It is used as a volume management back-end. Pools, volumes and snapshots can be created with btrfs backend and here is what it means from the btrfs point of view:

Lvm backend¶

Pools, volumes and snapshots can be created with lvm, which pretty much match the lvm abstraction.

Crypt backend¶

Crypt backend in ssm is currently limited to only gather the information about encrypted volumes in the system. You can not create or manage encrypted volumes or pools, but it will be extended in the future.

MD backend¶

MD backend in ssm is currently limited to only gather the information about MD volumes in the system. You can not create or manage MD volumes or pools, but it will be extended in the future.

EXAMPLES¶

List system storage information:

# ssm list

List all pools in the system:

# ssm list pools

Create a new 100GB volume with default lvm backend using /dev/sda and /dev/sdb with xfs file system:

# ssm create --size 100G --fs xfs /dev/sda /dev/sdb

Create a new volume with btrfs backend using /dev/sda and /dev/sdb and let the volume to be RAID 1:

# ssm -b btrfs create --raid 1 /dev/sda /dev/sdb

Using lvm backend create a RAID 0 volume with devices /dev/sda and /dev/sdb with 128kB stripe size, ext4 file system and mount it on /home:

# ssm create --raid 0 --stripesize 128k /dev/sda /dev/sdb /home

Extend btrfs volume btrfs_pool by 500GB and use /dev/sdc and /dev/sde to cover the resize:

# ssm resize -s +500G btrfs_pool /dev/sdc /dev/sde

Shrink volume /dev/lvm_pool/lvol001 by 1TB:

# ssm resize -s-1t /dev/lvm_pool/lvol001

Remove /dev/sda device from the pool, remove the btrfs_pool pool and also remove the volume /dev/lvm_pool/lvol001:

# ssm remove /dev/sda btrfs_pool /dev/lvm_pool/lvol001

Take a snapshot of the btrfs volume btrfs_pool:my_volume:

# ssm snapshot btrfs_pool:my_volume

Add devices /dev/sda and /dev/sdb into the btrfs_pool pool:

# ssm add -p btrfs_pool /dev/sda /dev/sdb

ENVIRONMENT VARIABLES¶

LICENCE¶

(C)2011 Red Hat, Inc., Lukas Czerner < lczerner@redhat.com> This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see < http://www.gnu.org/licenses/>.

REQUIREMENTS¶

Python 2.6 or higher is required to run this tool. System Storage Manager can only be run as root since most of the commands requires root privileges. There are other requirements listed bellow, but note that you do not necessarily need all dependencies for all backends, however if some of the tools required by the backend is missing, the backend would not work.

Python modules¶

System tools¶

Lvm backend¶

Btrfs backend¶

Crypt backend¶

AVAILABILITY¶

System storage manager is available from http://storagemanager.sourceforge.net. You can subscribe to storagemanager-devel@lists.sourceforge.net to follow the current development.

AUTHOR¶

Lukáš Czerner <lczerner@redhat.com>

COPYRIGHT¶

2012, Red Hat, Inc., Lukáš Czerner <lczerner@redhat.com>