Tape is not dead

[Joe_Pfeiffer]

When I first started working with NetBackup I got to work with a great team of NetBackup engineers on the Media Server team.  These guys write a lot of the code that moves data through a NetBackup Media Server that interacts with tape and disk devices which is a pretty important role in the overall products since it is what touches the data and puts it where it belongs.  They have been involved in reviewing, modifying and implementing the industry standards (the T10 SCSI specification) and honestly are some of the smartest guys I know.  Except for when Keith spilled coffee inside our IBM TS3500 (still works!).

Sometimes they take heat since everyone is talking about disk and not tape these days.  Well tape is not dead and here is a few reasons why:

• Tape is well established, portable, encryptable and relatively low cost.

• Tape is "green" when compared with disk since it doesn't require any power

• Data-at-rest on tape is safe, impervious to viruses and accidental data loss.

• Upgrade/expansion is much cheaper with tape and the upper bound on your total storage capacity is infinite.  You do not need to go to a hardware vendor to buy marked-up expansion hard drives, you simply go to Amazon.com and buy more tapes that are interoperable from several companies (Maxwell, TDK, etc)

• DR without a full-blown data center - all you need is the tapes a server and a tape drive.

 
So what is so special about NetBackup's tape capabilities?

NetBackup does not only claim support for the tape drives included in its hardware compatibility list (HCL) but it also has longstanding and very close relationships with the major tape vendors and actually tests extensively with all supported tape drives before claiming support.  These close relationships and extensive testing give NetBackup many advantages like being able to track and support new capabilities such as WORM and encryption immediately upon release.  Usually NetBackup is first to market with new drive support because of these close relationships and NetBackup is used to test the tape drives before they go in to mass manufacturing at these companies.  Pretty cool, NBU is the QA tool for a new tape drive.

NetBackup is also able to deliver support for new devices asynchronously from NetBackup releases and usually with no new code - this is a very big advantage over others since you don't have to wait for a patch.  Just buy some new drives, plug it in and you're good to go.  At the very least you would need a new device mappings file which is a small text file that is updated on the support site every few weeks (ie not a patch).

NetBackup tape capability reduces cost by sharing tape drives amongst heterogeneous media servers and NDMP devices. Using Persistent SCSI Reservation allows NetBackup the ability to actually failover tape drives on a cluster also.  Other products must cycle power on their drives first (because the reservation is owned by the HBA).

Media sharing, a new feature in NetBackup 6.5 and above, is a hot media handoff capability enabled by persistent SCSI reservations.  This eliminates a mount/unmount cycle, SCSI reserve and release cycle and a rewind/reposition cycle.  This makes streaming backups even faster when it matters since everyone should know that tape is faster than disk when they are streaming/writing at full speed.  Media sharing allows NetBackup to maximize this streaming where others waste time repositioning for each new tape. Media sharing also offers the most efficient use of tape media possible since data is pooled together on the most full piece of media. Less partially full tapes when offsiting means you buy less storage.

Enhanced bus fault tolerance is built in to NetBackup and is something we internally call "resume logic".  It's patented technology that allows for NetBackup to recover from fibre channel failures.  You can literally unplug a fibre channel tape drive in the middle of writing and plug it back in without failing a backup.  It just picks up where it left off. This area also has the ability to recognize a variety of vendor-specific codes called "tape alerts" in order to make intelligent decisions about disabling (or what we call "downing") a bad drives or freezing bad media, etc.  This can then tell people what happened so the problem can be fixed while not disrupting other backup operations. Also as a precaution NetBackup uses tape media confirmation through SCSI cartridge serial numbers which provides another level of protection against overwriting media or accessing data where it shouldn't’t be.  Even if a tape is accidentally relabeled it won't be overwritten if the internal serial number of the tape doesn't match what NetBackup has recorded from the previous backups that were written there.

NetBackup Vault provides long-term command and control for offsite media management and tape media vaulting.  Again, the interoperability of NetBackup with the various tape library vendors and interface types (LAN, SCSI, NDMP) is exceptional in the industry and critical to our Vault feature.

Performance. NetBackup has the ability to tune for any environment to maximize for total throughput, total tape drive usage, memory usage, and even throttling for network utilization.  Nobody comes close to NetBackup’s ability to tune to a specific customer's environment and needs. NetBackup is able to stream data to tape as fast as the underlying hardware will allow; anybody who says they are faster at backing up to tape is simply manipulating the numbers.