back to article Does it even make sense to buy a VTL today?

I’ve never been fond of VTLs (virtual tape libraries). I like deduplication but it quickly became a feature and is not a product. And lately we all want more out of backups, don’t we? Data Domain did a great job in building a brilliant deduplication-based appliance in 2001, but that was 2001. And, while it lasted, having the …

  1. Nate Amsden

    you referring to tape in general or VTL specifically?

    Because to me tape in general is still useful. The distinction between OFFLINE and OFFSITE. Wouldn't want someone to fat finger a command and delete all data and all backups(or an attacker do it). With so many things driven by an "API" these days it's easier than ever, more so with cloud services.

    Having to have a human physically insert a tape into a library in order to access it is appealing to me anyway. Not to say that tape is the only backup, having onsite (online), and offsite (online) backups are still very useful but as a last resort I still consider it a good idea to have offline backups as well, after being written to physically disconnected from any level of automation that would allow it to be destroyed remotely -- whether that is on tape or another medium doesn't really matter though tape seems like the most likely target.

    1. AdamWill

      Re: you referring to tape in general or VTL specifically?

      Given that VTL is in the title of the article, and is repeated about two dozen times, I'm gonna go out on a limb and say that's what he was talking about.

  2. Anonymous Coward
    Anonymous Coward

    " I was the greatest fan of the Sun Fire x4500 and they always served like the best of the VTLs for my customers. "

    The 4500 a.k.a. Thumper was developped for the video streaming market but didn't really take off as expected.

    Instead they sold it as mass / archival storage. ZFS is good for JBODs so it was a good fit.

    However, it was extremely awkward to replace drives from the top of the box and ontop of that it had two drives per drive tray.

    You could get killed by a rack tipping over, just by replacing a drive.

    As far as VTLs go - tgey still make sense for legacy systems that want or need to talk to a tape drive...either way. VTL are a support nightmare. The biggest issue was actually with backup admins.

    They would just increase VTL tape slot amount without telling the backup application...

    I suppose that was a training issue...

    1. Justicesays

      Remember kids...

      >You could get killed by a rack tipping over, just by replacing a drive.

      always extend the Rack anti-tilt bars before attempting to install or remove anything from the rack!

  3. Stevie


    Never underestimate the bandwidth of a station wagon full of tapes barreling down the freeway.


  4. Anonymous Coward
    Anonymous Coward

    Yes & No

    Great article. I agree completely that the traditional grandfather,father,son approach to backup and recovery is dying a slow death. VTL's were a band-aid meant to allow customers to utilize disk as though it were tape. Tape is still hands down the most economical way to backup, the problem is the world is changing to one of more immediate requirements. Smarter replication technologies, CDP, and yes Object come to mind. I will argue however, that Object is not necessarily cheaper than a deduplicating VTL, particularly to small and mid-size customers. Erasure coding utilizes a lot of capacity, and the price point doesn't really become economical until you push north of 200-250+TB. Not a big number for backups, but big enough to scare many away from an unknown entity such as object, which arguably would still have longer full volume restore times than tape, and certainly a VTL.

  5. Anonymous Coward
    Anonymous Coward

    VTL was an answer to tapes and it's linear nature.

    Disk/JBOD or NAS was the next evolution to VTL. Removing the complexity of still managing tape, even if virtual.

    DataDomain was NEVER a VTL only device. VTL was an option. Few folks actually used that option in my experience. More preferred ethernet. Only certain use cases dictated VTL whether it compatibility, comfort with tape, or comfort with the transport medium.

    Symantec came along and really started to change things with OST. Which vendors like DataDomain, ExaGrid, and a few others supported. Remove VTL, use simpler/cheaper Ethernet, In some cases a highly optimized NFS protocol, in other cases an optimized packet/payload with other intelligence like optimized duplication/replication. This not only sped up backups, but allowed one to remove one more administration console by letting NBU manage replication and not the appliances.

    The thumper back then was novel for what it was, a big NAS and ZFS was thought of the next big thing. It's shine quickly turned to rust with the acquisition of Sun by Oracle.

    That being said, VTL is alive and kicking today. Some dedupe backup appliances still only support that. Some applications like TSM seem to work better with it. Some OS's can only use that (AS400/iSeries,Mainframe). Then there are some old school grumpy Unix dudes that still like "managing," tape...

    The ideal solution can do BOTH. Act as a VTL if needed, but also the more sought after CIFS/NFS connectivity. All concurrently.

    The pie in the sky solution gets rid of backup servers altogether, or at least getting them out of band, and being able to backup directly to your storage target. Then you can make multiple copies of that data via snaps, replication, clones, etc.

    I suggest you take a look at the TechDay videos of Cohesity on data protection on youtube. Those guys get grilled and stomped on about data protection. The rest of their use cases are great, but data protection, no thank you.

    This article would have been super back in circa 2007 or so. It seems to be missing a lot of relevant information let alone real world examples.

    1. bofh1599

      There is a FUJITSU CS800 on the market which does VTL, followed by dedup, followed by replication. And NFS for other backup ways. Reduces the numbers of LTO's in branch offices. Targeting at running backup solutions to replace the backup target without complete reconfiguration. The Author thinks fancy, that's his job, but reality is more conservative and mixed solutions blend the benefits, in parallel killing the drawbacks.

  6. dpk

    "and while it lasted" ... ? EMC still enjoys very strong market share with Data Domain. It was clearly a very good & profitable acquisition. Not sure you can credit ZFS with the same success.

  7. Anonymous Coward
    Anonymous Coward

    Some VTLs are faster, some aren't.

    Thanks for posting the article!

    All VTLs aren't created equal. From what I understand, certain VTLs can be faster than NAS/DAS/SAN storage for backup if they don't use a file system on the internal disks (back-end). There's no OS file system overhead (file allocation tables/permissions/etc.) and no need for virus scanners monitoring every write operation. With tape emulation, raw disk storage on the back-end, and sequential blocks being streamed by the backup software, they can be lightning fast. Also, because there is no file system, good VTLs are less likely to be attacked by viruses and crypto-lockers.

    Over the years, many VTLs have become burdened with feature bloat. They try to do too much and sacrifice performance, whether backup or restore or worse, both. Data Domain, for example, can be slower than tape when restoring data from deduplicated tapes. Tape continues to get faster (look at LTO7 uncompressed transfer speeds; not bad) so getting a VTL that is slower than tape doesn't make sense anymore.

    I've always like the VTLs by Cybernetics. They aren't as well known as Data Domain but their units are faster on backups and restores and their implementation of dedupe doesn't sacrifice restore speed. They cost a lot less too.

    Another thing to consider is the backup software being used. Certain packages aren't really a good choice for a VTL. Veeam comes to mind.

    I agree with the above comment about AS/400, iSeries and Power Servers being a great fit for VTLs.

    In addition to Unix and mid-range IBM customers, anyone concerned about keeping their local backup safe from viruses and crypto-lockers might want to consider a virtual tape library. I've seen a huge surge in customers getting plagued with this in the past six months (primary storage and disk backups getting compromised).

  8. Anonymous Coward
    Anonymous Coward

    It may have just been me, but I got lost about the point

    First it seemed like the author was hinting that it was more cost effective to build our own VTL. Which I would agree with. Only catch is if you buy one and pay for support, mgt has someone to blame if something goes wrong who's not the clever SA reducing cost.

    A homegrown ZFS solution could be used for SMB thanks to Samba which has done a very good job at keeping features up to date with changes by MS.

    The author noted he was a former Sun Microsystems VAR. I'm surprised there was no mention of SAMFS or OpenAFS. Or that ZFS can also be used to share out an iSCSI tape drive or drive to a client.

    Disclosure: I've got a home Solaris 11 file/backup server at home using ZFS to keep our data safe.

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