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LTFS in action
The ecosystem around LTFS is growing rapidly and to the point of ensuring its adoption. One organization helping to enable this ecosystem is the Active Archive Alliance. This vendor consortium is dedicated to developing open standards that allow LTFS to be deployed across multiple storage tiers. In essence, it lets LTFS create a single logical volume across both disk and tape subsystems.
Of course, having a volume that spans media types isn’t enough. Applications are needed to
Oracle also offers solutions based on LTFS. “The idea of a 5 TB thumb drive is pretty cool,” quipped Tom Wultich, Oracle’s director of product management for tape. He’s referring to the StorageTek T10000C tape drive that’s LTFS-enabled and has a 5 TB capacity. “Users can easily move a tape from one LTFS system to another. An example would be the need to move a large media file from one system to another for editing,” Wultich said. “Transferring a multiterabyte file over the network may not be practical. Instead, one user can simply drag and drop the file to the tape and give it to the other user, who can then mount it just like a share or thumb drive.”
Crossroads System Inc.’s StrongBox product is all-in when it comes to leveraging LTFS for long-term storage archive. Robert Sims, Crossroads’ president and CEO, describes StrongBox as “a NAS head for tape.” The StrongBox appliance uses disk as front-end cache and supports multivendor tape connectivity on the back end. The product supports both CIFS and NFS.
StrongBox features are designed to provide the reliability necessary to ensure data recoverability for the long haul. Sims characterizes StrongBox as self-healing. By that, he means it supports dual copy to two different tapes, replication of tapes and failing over to a secondary copy if the first can’t be read. StrongBox monitors both drive and media error rates to detect degrading media. In the event of a media hard error, StrongBox will initiate a tape copy to create a replacement.
One issue for online file access using tape is the latency of a data read. CIFS and NFS will usually time out before the data can be mounted, accessed and retrieved from tape. StrongBox maintains a 512 KB buffer on disk to satisfy the latency while it retrieves the whole file from tape. StrongBox doesn’t presently support data modify or delete, although support for data delete is expected in 2012.
LTFS might also enable lower cost methods for common uses. For example, using tape as a write target in a dual-write scenario would effectively offer continuous data protection (CDP). Moreover, having two copies in different locations would assure data safety and a very granular RPO. It wouldn’t eliminate the need for B/R applications, which can facilitate point-in-time restores and the most recent version of the whole file system. However, for user self-service and the ability to retrieve specific file versions, LTFS may be just the solution.
R.I.P. tape? Not so fast
During the last five decades, the death of tape has been declared in at least four of them. Although tape wasn’t really threatened as an archive solution, LTFS brings a new dynamic to the needs of long-term data archive and access. With Active Archive, it also makes tape a viable tier 4 repository in the data center. Seamless access and low cost should extend tape’s lease on life for at least another decade.
BIO: Phil Goodwin is a storage consultant and freelance writer.
This was first published in February 2012