Aleksandr Fomenkov, 123RF.com

Storage system with OpenSolaris and Comstar

Storage Star

Article from ADMIN 00/2010

By Djordje Gladovic

What used to be the domain of expensive storage solutions is now available on a tight budget with the free OpenSolaris operating system and Comstar. You can set up your own storage system that supports both iSCSI and Fibre Channel.

The advanced ZFS filesystem by Sun, and now Oracle, heralded a major change in the storage sector. ZFS's amazing qualities are an obvious choice for a storage system, but Sun failed to provide a viable network-attached storage system. Sun engineers knew the implementation of a modern framework that served up block devices throughout the network was the next step. The resulting product was Comstar (Common Multi-Protocol SCSI Target, [1]), a subsystem that uses current and future media and protocols to provide storage in the form of block devices. In combination with OpenSolaris [2], ZFS, and the NFS and CIFS implementation, Comstar anchors a fully unified storage system.

ZFS isn't actually a requirement: Comstar is capable of providing files and partitions (known as slices in Solaris-speak) to arbitrary consumers in the form of logical units.

But ZFS adds value in the form of snapshots, clones, and thin provisioning, and it is thus very much worth using. The similarities with a NetApp storage system are hard to overlook [3].

You can take your first steps toward OpenSolaris and Comstar on a virtual machine, although a virtual configuration restricts the choice of transport protocols to iSCSI. This approach is comparable to the installation of the popular Openfiler system on Linux. Incidentally, Oracle has previously used Openfiler in the Oracle RAC and Oracle Grid HowTos. After acquiring Sun, Oracle might want to change this and replace Openfiler with OpenSolaris and Comstar.

The deployment of an OpenSolaris/Comstar system involves the following steps: