Open CAS Linux

Open CAS accelerates Linux applications by caching active (hot) data to a local flash device inside servers. Open CAS implements caching at the server level, utilizing local high-performance flash media as the cache drive media inside the application server as close as possible to the CPU, thus reducing storage latency as much as possible. The Open Cache Acceleration Software installs into the GNU/Linux operating system itself, as a kernel module. The nature of the integration provides a cache solution that is transparent to users and applications, and your existing storage infrastructure. No storage migration effort or application changes are required.

Open CAS is distributed on BSD-3-Clause license (see https://opensource.org/licenses/BSD-3-Clause for full license texts).

Open CAS uses Safe string library (safeclib) that is MIT licensed.

Installation

We recommend using the latest version, which contains all the important fixes and performance improvements. Bugfix releases are guaranteed only for the latest major release line (currently 24.9.x).

To download the latest Open CAS Linux release run following commands:

wget https://github.com/Open-CAS/open-cas-linux/releases/download/v24.9/open-cas-linux-24.09.0.0900.release.tar.gz
tar -xf open-cas-linux-24.09.0.0900.release.tar.gz
cd open-cas-linux-24.09.0.0900.release/

Alternatively, if you want recent development (unstable) version, you can clone GitHub repository:

git clone https://github.com/Open-CAS/open-cas-linux
cd open-cas-linux
git submodule update --init

Source compile and install

To install all required python packages run the following command:

python3 -m pip install -r requirements.txt

To configure, build and install Open CAS Linux run following commands:

./configure
make
make install

The ./configure performs check for dependencies, so if some of them are missing, command will print their names in output. After installing missing dependencies you need to run ./configure once again - this time it should succeed.

NOTE: If after installing CAS, your system boots into emergency mode due to the "Failed to start opencas initialization service." error, you need to force SELinux relabelling in permissive mode on your filesystem.
Refer to the Open CAS documentation for details.

RPM/DEB install

Alternatively, you can generate RPM/DEB packages from downloaded sources and install those packages instead. To do so, simply run:

on RPM based systems:

make rpm
rm -f packages/*debug*
dnf install ./packages/open-cas-linux*.rpm

on DEB based systems:

make deb
apt install ./packages/open-cas-linux*.deb

Package generating script will inform you of any missing dependencies. You can find detailed instructions in the Open CAS documentation

Getting Started

To quickly deploy Open CAS Linux in your system please follow the instructions available here.

Documentation

The complete documentation for Open CAS Linux is available in the Open CAS Linux Administration Guide.

Running Tests

Before running tests make sure you have a platform with at least 2 disks (one for cache and one for core). Be careful as these devices will be most likely overwritten with random data during tests. Tests can be either executed locally or on a remote platform (via ssh) specified in the dut_config.

1. Go to test directory cd test/functional.
2. Install dependencies with command pip3 install -r requirements.txt.
3. Create DUT config. See example here. a) Set disks params. You need at least two disks, of which at least one is an SSD drive. b) For remote execution uncomment and set the ip, user and password fields. c) For local execution just leave these fields commented.
4. Run tests using command pytest-3 --dut-config=<CONFIG> where <CONFIG> is path to your config file, for example pytest-3 --dut-config="config/dut_config.yml".

Contributing

Feel like making Open CAS Linux better? Don't hesitate to submit a pull request! You can find more information about our contribution process here. In case of any questions feel free to contact maintainer.