Melio fs

Melio fs (Melio File System) enables clusters of Windows machines to share files on SAN storage. With Melio fs, partitioned volumes on the SAN appear as local disk drives on the machines, with each machine communicating (via TCP/IP) with all other machines in the cluster to avoid file contention issues. The vendor notes that the drives appear as local drives to Windows operations, and thus multiple Windows technologies are supported when using the volumes including Active Directory, network load balancing, ACLs, MS MPIO, volume expansion, and more.

To use the File System, the administrator first installs the Melio fs driver on all machines that will use the shared storage (each machine must have its own connection to the SAN via FC or iSCSI communications). Next, an individual partition (or individual partitions) are selected on the SAN, and from a single Melio fs-enabled machine the administrator maps a drive letter to the partition and then reformats that partition (a destructive process) to support the Melio File System. All other machines in the cluster will then automatically discover the volume and provide access to it, with file locking tasks and commands handled via the TCP/IP communications between the machines.

Various configurations can be set to optimize the performance of the platform; including per-host or per-process QoS settings (certain hosts or their specific applications can be given higher priority access to the shared storage), specific timing metrics (such as the maximum length of time an I/O operation can last, or the maximum network round trip time), and the ability to disable file access time updates to shared files on a per-process basis; this latter tweak is noted by the vendor to potentially improve overall performance of the platform, at the cost of not maintaining the last accessed time on individual files for those applications selected. Additionally, individual processes can be set such that Melio automatically reports the fs volumes as formatted via NTFS, to avoid confusion with the Melio fs designation.

Melio fs is a journaled file system; and, as such, when an individual machine attempts to connect to a Melio volume following a crash it will attempt to restore the data based on journal entries. The vendor warns that this process may delay this initial access to the drive.

New features in the latest Melio fs release include support for access to Melio fs volumes from Citrix XenServer virtual machines (in addition to existing support for VMware ESX and Hyper-V); support for shared host access to a LUN for Windows Server 2008 R2 beta; and the addition of specific distributed locking components optimized for block objects such as virtual disk files and databases.

Melio fs is available now,with pricing starting at $5,000 per SAN connected server. Contact Sanbolic for further information.