* README *
* Online Hierarchical Storage Manager *
* version 1.2 *
These are the release notes for OHSM version 1.2. Please read them
carefully before installation of OHSM kernel module.
WHAT IS OHSM ?
OHSM is a tool to manage and move data across various class of storage.
It can help users to intelligently place and move data across tiers
based on the attributes of the data. OHSM supports background movement of data
without any visible change in namespace to user.
OHSM requires kernel sources for your running kernel in order to compile. OHSM
is built as an external module with recompilation required for ext4. It also
needs that ext4 should be built as module for your current kernel or a complete
rebuilt of kernel with ext4 compiled as module is required. The current version (1.2)
of OHSM is based upon Linux 188.8.131.52 kernel.
svn co https://ohsm.svn.sourceforge.net/svnroot/ohsm ohsm
2. Through git:
git clone ssh://email@example.com/gitroot/ohsm/latest ohsm
It creates ohsm directory having source code in it.
Boot from the new vanilla 184.108.40.206 kernel. Build the kernel with ext4 as a module.
OHSM compilation creates and installs the required ext4 module. Build and install
the OHSM module. To compile OHSM, user requires device-mapper-devel and libxml2-devel
The simplest way to compile this package is:
1. "./configure" to configure various packages for the system.
2. "make" to compile the packages.
3. Type "make install" to install the programs and any data files and
documentation. During "make install", the script asks for automatic
installation of ext4 module. Select 'y' if you want to install it
automatically. The install script requires root privileges to install
the OHSM binaries. By default it assumes to have sudo access to the user.
If sudo is not enabled on system or the user doesn't have sudo access,
these files need to be copied manually using superuser privileges
to the appropriate directories and the newly built ext4 module should be updated
in /lib/modules/`uname -r`/kernel/fs/ext4
4. Type "insmod kernel/ohsm.ko ohsm_enable_debug=<debug_level>" to insert
OHSM module into the kernel. The debug levels may vary from 0-8.
Quick overview of some OHSM commands::
1. ohsm enable <path_of_policy_file>
2. ohsm status <mount_point>
3. ohsm disable <mount_point>
4. ohsm update -m <mount_point> -a <path_to_allocpolicy_file>
5. ohsm update -m <mount_point> -r <path_to_relocpolicy_file>
OHSM provides a `tests` directory, through which OHSM can be tested. You can
use the `test_ohsm.sh` script that would enable OHSM on your system. Through
this users can check if all the provided features of OHSM work correctly.
Type the command "./test_ohsm.sh -e" for enabling. You can try various other
features or also use the help utility to check the various facilities
For more information you can visit ohsm home page at the URL:
The OHSM source code and related files can be downloaded from the URL:
OHSM wiki page can be found at the URL:
Popular Pages in wiki:
* FAQs for new users and installation issues
* Getting Started For Developers
* Getting Started For Users
* Command Line Interface