Drobo: Thin Provisioning

If you know me, you know that I’m a huge proponent of Drobo.  As of late, the frustration level with Drobo is increasing and it may have edged away at this enthusiasm.

My most recent frustration came when I upgraded a drive in my Drobo to increase the usable space to more then 2TB.  After the Drobo finished updating all of its partitions, I was left with a partition that was labeled ‘unallocated’ in the Drobo dashboard.  After searching the interwebs (which yielded absolutely nothing on Drobo’s site for ‘unallocated’) and posting on a couple of forums, I was led to this:

http://support.datarobotics.com/app/answers/detail/a_id/23/session/L3NpZC9LZFU0M3JWag%3D%3D/sno/0

This is telling me that I’m stuck with adding partitions to my Drobo of maximum size 2TB because of a decision I made when I originally set it up, at which time I was not told how this setting would affect me as I add disk space.  Further, I think that Drobo’s claims of being both “simple” and “scalable” are misleading as this limitation is not spelled out up-front and if you don’t understand this, the affects of scaling can be considerably different then what is expected.

Now that I have have realized this, the only way to have 1 single partition again is to (in Drobo’s own words) “migrate the data onto another Drobo or storage device, reformat the original Drobo device to the volume size of your choice, and then move the data back.”  With 2TBs of data, not only is this a huge pain in the ass, I need to buy another drive in order to fit the entirety of my Drobo on a disk before reformatting.

I think this a huge failure on Drobo’s part that could be fixed one of 2 ways:

  1. Be explicit about how setting this soft limit is actually a hard limit on the amount of space that can be allocated to a volume.
  2. Drobo creates a tool to resize partitions to change storage space on a partition.

A tool in this situation would prove extremely handy and would prevent any confusion or problems when going over this thinly provisioned partition cap.

Any help here, Drobo?

  • Matthew Trumbell

    Boo!

    This is the main reason I’m wary of solutions like Drobo to begin with. With a proprietary-ish OS, a proprietary filesystem, and a smallish user base good luck finding a hack to work around it. I will say, though, that such resizing operations are possible on general purpose linux (which is what Drobo is based on under all that candy coating). So there is some hope.

    But you should forget all that: do a BYO linux machine with a RAID card. You’ll spend a weekend setting it up, but you’ll have a lot of online support building it, you’ll have plenty of online support if anything goes wrong, you get full control AND you get a general purpose machine with your storage solution.

  • Matthew Trumbell

    Boo!

    This is the main reason I’m wary of solutions like Drobo to begin with. With a proprietary-ish OS, a proprietary filesystem, and a smallish user base good luck finding a hack to work around it. I will say, though, that such resizing operations are possible on general purpose linux (which is what Drobo is based on under all that candy coating). So there is some hope.

    But you should forget all that: do a BYO linux machine with a RAID card. You’ll spend a weekend setting it up, but you’ll have a lot of online support building it, you’ll have plenty of online support if anything goes wrong, you get full control AND you get a general purpose machine with your storage solution.

  • G. Canidae

    So what is the problem? That you have multiple 2TB drives mounted? I have had a Drobo since 8/07. I don’t recall them ever saying anything more than that you can increase the capacity of your Drobo “forever”…. it is the “forever” claim that is suspect, not that there is a 2 TB “chuck size” for upgrades. FWIW, this is only a limitation of the first gen product and it was because dumb XP can’t grow beyond 2 TB. My most recent Drobopro defaults to 16TB.

    FWIW, it seems that your problem resolution strategy is fatally flawed, and potentially lethal — the vendor’s site was your last resort after trying several other sources.

  • G. Canidae

    So what is the problem? That you have multiple 2TB drives mounted? I have had a Drobo since 8/07. I don’t recall them ever saying anything more than that you can increase the capacity of your Drobo “forever”…. it is the “forever” claim that is suspect, not that there is a 2 TB “chuck size” for upgrades. FWIW, this is only a limitation of the first gen product and it was because dumb XP can’t grow beyond 2 TB. My most recent Drobopro defaults to 16TB.

    FWIW, it seems that your problem resolution strategy is fatally flawed, and potentially lethal — the vendor’s site was your last resort after trying several other sources.

  • David Trumbell

    That’s my exact problem. I want one large partition mounted and usable regardless of what drives I stuff in there. On your DroboPro, what happens when drive size increases to the point where you have over 16TB of storage in it? You can’t resize the 1 partition. Instead, you have to copy all 16TB off the Drobo and reformat it.

    As for my resolution strategy, believe me, I started on the Drobo site and scoured it for any resolution to the ‘unallocated’ disk space issue. Further, I even contacted Drobo support, but they gave a response that was less then useful (see below) and never responded to my second query. It wasn’t until I left the Drobo site and support that I started getting any kind of real answers…

    Response from Drobo: “When you refer to “unallocated space” it sounds like you are looking at a disk management utility. Drobo devices cannot use every bit of hard drive space you might have physically on your hard drives. This is due to the protection mechanisms. I recommend you open Drobo Dashboard and on the main page, click “How is my storage being used?” This will accurately show you how much room is “Reserved for expansion” If you want to know how much actual usable storage you have with any combination of hard drives, please use our Capacity Calculator: http://www.drobo.com/resources/drobolator.php. Operating systems will report the volume size at whatever size you set up with Drobo Dashboard, regardless of how much actual physical disk space you have in your Drobo. This, however, does not mean you have that amount of space available for use. It is a “virtual” volume and you can add disk drives until you reach the limit. I hope this helps, but if you have further questions, please contact technical support: http://www.drobo.com/support/contact-support.php.”

  • David Trumbell

    I have to admit I should have started here. However, it’s hard to overlook how attractive something like a Drobo is (especially if you want to save time during setup) and I’m kind of stuck now that I have made the investment in the Drobo. I will definitely look further into a vanilla Linux box to augment what I already have when I’m in need of a new storage device.

  • David Trumbell

    I have to admit I should have started here. However, it’s hard to overlook how attractive something like a Drobo is (especially if you want to save time during setup) and I’m kind of stuck now that I have made the investment in the Drobo. I will definitely look further into a vanilla Linux box to augment what I already have when I’m in need of a new storage device.

  • Matthew Trumbell

    There’s always e-bay. 😉 And you can reuse the drives…

    The assumptions of the poster below are a little…strange, not to mention detached from the info you presented. You even got a lecture on proper problem solving. So helpful!

    Info on working with their thin provisioning technology seems pretty hard to come by, aside from initial setup. I will say that the technology sounds pretty cool. Upgrading a regular old RAID array is a bit of a pain (usually a disk-by-disk upgrade with a RAID rebuild in between each, then you still have to deal with growing your partitions). It is technically possible, but somewhat of a risky op. It seems that with either Drobo or RAID, unless you have a separate device with equal amounts of capacity to do a full backup, you are going to feel a bit of pain.

    As a possible workaround: have you considered using symlinks to distribute data across multiple partitions? Not a great solution, really, but it is what I do in my RAID-less, Drobo-less world of external USB drives.

    BTW, this post is on the first page of Google for a search on “resize drobo partition”.

  • Matthew Trumbell

    There’s always e-bay. 😉 And you can reuse the drives…

    The assumptions of the poster below are a little…strange, not to mention detached from the info you presented. You even got a lecture on proper problem solving. So helpful!

    Info on working with their thin provisioning technology seems pretty hard to come by, aside from initial setup. I will say that the technology sounds pretty cool. Upgrading a regular old RAID array is a bit of a pain (usually a disk-by-disk upgrade with a RAID rebuild in between each, then you still have to deal with growing your partitions). It is technically possible, but somewhat of a risky op. It seems that with either Drobo or RAID, unless you have a separate device with equal amounts of capacity to do a full backup, you are going to feel a bit of pain.

    As a possible workaround: have you considered using symlinks to distribute data across multiple partitions? Not a great solution, really, but it is what I do in my RAID-less, Drobo-less world of external USB drives.

    BTW, this post is on the first page of Google for a search on “resize drobo partition”.

  • David – Sorry about your frustration. As mentioned by one of the commenters, we have now changed the default volume size to 16TB assuming the host OS can support this. Windows XP and some older operating systems only supported volumes up to 2TB.

    Unfortunately the size of the first volume you create sets precedence for future volumes once drive capacity exceeds the size of the volume. You can still continue to increase your capacity, but the Drobo will show up as multiple 2TB drives instead of a single drive.

    While I know this is not ideal, if you can copy your data temporarily from the Drobo to another storage device, you can reformat the volume to 16TB which would then be the default for all volumes going forward.

    Regards,

    Jim Sherhart
    Data Robotics, Inc.

  • David – Sorry about your frustration. As mentioned by one of the commenters, we have now changed the default volume size to 16TB assuming the host OS can support this. Windows XP and some older operating systems only supported volumes up to 2TB.

    Unfortunately the size of the first volume you create sets precedence for future volumes once drive capacity exceeds the size of the volume. You can still continue to increase your capacity, but the Drobo will show up as multiple 2TB drives instead of a single drive.

    While I know this is not ideal, if you can copy your data temporarily from the Drobo to another storage device, you can reformat the volume to 16TB which would then be the default for all volumes going forward.

    Regards,

    Jim Sherhart
    Data Robotics, Inc.

  • David Trumbell

    Jim – Thanks for the response. While changing the default is a temporary fix, I don’t see it as a long term solution (what if I go over 16 TB??). Is there any plan to offer a tool to resize a Drobo partition?

  • David Trumbell

    Jim – Thanks for the response. While changing the default is a temporary fix, I don’t see it as a long term solution (what if I go over 16 TB??). Is there any plan to offer a tool to resize a Drobo partition?

  • Scott

    This is something that I’ve been longing for myself. I would love to be able to dynamically resize a Drobo volume. Aside from the obvious problem of limiting the size, this removes the side effect of the thin provisioning preventing applications like Truecrypt from being able to encrypt the entire device.

    If I were able to control the volume size on the Drobo, using Truecrypt for FDE would become a possibility (even if it meant decrypting everything before resizing the volume, while annoying and timing, it’s understandable and still feasible).

  • Scott

    This is something that I’ve been longing for myself. I would love to be able to dynamically resize a Drobo volume. Aside from the obvious problem of limiting the size, this removes the side effect of the thin provisioning preventing applications like Truecrypt from being able to encrypt the entire device.

    If I were able to control the volume size on the Drobo, using Truecrypt for FDE would become a possibility (even if it meant decrypting everything before resizing the volume, while annoying and timing, it’s understandable and still feasible).

  • Hi Jim,

    I bought my Drobo last summer and setup a 2TB partition (I presume) by default at the time. Tonight I slid in a new 1TB drive and so now I have 735gb unallocated disk. I stopped creation of the new volume before realizing that I could not extend the existing one.

    It looks like a tool to resize a Drobo partition is available in the Pro and Elite products but not my regular 2nd-gen Drobo.

    Are there plans to extend this tool into the rest of the product-line and if not, is there a way to re-trigger creation of a new volume using the dashboard ? I couldn’t find anything on the site.

    Thanks.

  • Hi Jim,

    I bought my Drobo last summer and setup a 2TB partition (I presume) by default at the time. Tonight I slid in a new 1TB drive and so now I have 735gb unallocated disk. I stopped creation of the new volume before realizing that I could not extend the existing one.

    It looks like a tool to resize a Drobo partition is available in the Pro and Elite products but not my regular 2nd-gen Drobo.

    Are there plans to extend this tool into the rest of the product-line and if not, is there a way to re-trigger creation of a new volume using the dashboard ? I couldn’t find anything on the site.

    Thanks.

  • Never mind, I got the new volume to trigger by disconnect and restart

  • Never mind, I got the new volume to trigger by disconnect and restart

  • Frank

    I’ll go further than suggesting “misleading.” David Trumbell is far too kind. I’ve been lied to about the ease with which Drobo can be expanded and configured, and I don’t like it all. I purchased two new 2tb drives and slipped them into the expansion bays of a Drobo system with 2 1.5 tb drives, and lo and behold, Drobo did not recognize them as increased space. As David suggested, we were never warned that formatting the hardware to match the original drive sizes limited expansion. To make the device reasonably useful and to have it act as advertised I will need to go out and buy a 2gb drive to move all the data off the Drobo, reformat Drobo, and then move all the data back. Why buy a Drobo in the first place? If I had the time and energy, I would sue for misrepresentation in small claims court. I don’t have the time, so I’ll simply resort to badmouthing Drobo. This is really incredibly dumb, or really, really incompetent design. Drobo, you want me to buy more products? Seriously? Why?

  • Mate, I’m with you on this one. I bought a Drobo thinking that it’ll be really easy to expand by simply putting in a new hard drive. So when I inserted a new 2TB drive and it came up as a new volume, I was very surprised. I’ve spent almost a few hours a day for a whole week trying to consolidate the volumes into one. The main problem is that I have a TM volume on the Drobo which, although is 800GB, sits on a volume that is 2TB.

    I’m trying to transfer this volume and the only way possible is by creating a 1:1 clone. I have a spare 1TB hard drive here which I was intending to clone to.. but because of the way cloning works, I actually need to clone to a spare 2TB hard drive, then reformat the drobo, then transfer it back.

    Jim Sherhart / Drobo, you’ve told us that it is “unfortunate” but WHY is it unfortunate? Is it unfortunate that the Company doesn’t have the expertise? Is it unfortunate that we made a poor investment decision? WHY is it that Drobo can’t resize like the Drobo Elite?

    Drobo Inc, you’re better than this. We expect better from you.

  • Jkw

    Drobo is a horse shit company that totally mis represented the need to do “maximum” volume creation first if you plan to really scale beyond the size of your original drive. Anyone who says to buy another drobo or hard drive to
    Migrate your data and then reestablish a larger volume to transfer your data back to is essentially saying their product is a failure as it does not simply scale unless you the user had the foresight to know how large beyond your current capacity you would need to be in the future.

  • Mallaire2112

    Wow…I wish I would have known this when I set up my Drobo.  This was very misleading on your behalf. I just added another drive and am getting hosed with a second volume.  Thanks Drobo.