Pegasus Raid vs Drobo

Discussion in 'Buying Tips and Advice' started by mashinhead, Nov 12, 2011.

  1. mashinhead macrumors 68020

    Joined:
    Oct 7, 2003
    #1
    Hey guys,

    I currently have an old first hand drobo that I bought second hand last year. I'm currently interested in buying a TB HD option and right now all there really is that is comparable to the Drobo is the Pegasus. But what I love about the Drobo is how versatile it is. I can swap in any size drive in any order I want. I know the Raid in the Pegasus isn't quite as easy and I wanted to know the limitations. How does that work compared the Drobo, what are the pros and cons.
     
  2. calderone macrumors 68040

    calderone

    Joined:
    Aug 28, 2009
    Location:
    Seattle
    #2
    The Drobo is slow and using proprietary RAID. Meaning, if your unit died and Drobo wasn't around you would be pretty much screwed. That isn't to say you would fair any better with the Pegasus, but it uses a standard RAID controller so there is some change of recovery.

    I am in the process of moving from my DroboPro to the Promise. The Peg is much faster. It doesn't even compare really. I was getting max 70MB/s on my DroboPro. That has degraded to 35MB/s write and 40MB/s read.

    On the peg, I am getting on average 300MB/s write and 250MB/s read (RAID 6).

    Configuring both is straight forward, and since the peg uses a standard controller, you get some more advanced options for configuration if you need different options across volumes.

    I am not sure which Drobo you are looking at, but I think you would be happier in the long run with the Peg.
     
  3. mashinhead thread starter macrumors 68020

    Joined:
    Oct 7, 2003
    #3

    Thanks for your response. I'm well aware that the pegasus is much faster and better. I guess my question was more related to what the drawbacks are of not using the propriatry raid that drobo uses. That particular one has a lot of advantages such as using any hard drive of any size, and upgrading whenever you want by just buying one hard drive. It's easy.

    But the traditional raids as i understand it doesn't have that advantage right? I have to use all the exact same drives of the exact same size. Which means if i need more space I have to buy and replace 4 drives right? Also what happens in the pegasus is a drive dies? I looked at both their models and the they support multiple raid configurations, (the 4 drive model less than the 6 drive one) so which is the best configurations.

    Either way I'm not really writing this post because I need to sold on the TB raid. I just want to have a clear understanding going in of what disadvantages exist so I'm aware and prepared for them.
     
  4. calderone macrumors 68040

    calderone

    Joined:
    Aug 28, 2009
    Location:
    Seattle
    #4
    For the Pegasus.

    1. You can put in a drive that is the same size or larger. My guess is that the additional space will be unavailable.
    2. The Pegasus manual suggest you can use any model you just have to meet these criteria:

    Type – Hard disk drive (HDD) or solid state drive (SSD)
    Interface - SATA 3 Gb/s or 6 Gb/s
    Spin speed - 7,200 RPM or 15,000 RPM
    Capacity – Equal size or larger

    It specifically says:

    So it seems there is some flexibility in placing drives in the unit. The biggest question being how it handles putting in a drive that is larger if you plan to add it to an existing disk array. See nutshell section for how you can bypass this.

    If a drive dies in the Pegasus, what occurs is going to depend on how your configured it.

    1. If you used a fault tolerant RAID mode, your data will be fine.
    2. You may have configured a spare drive, which means it will start rebuilding that drive to make up for the loss.
    3. If you did one of the above, you should replace that drive as soon as possible. Promise covers your drives for two years, so you can request a replacement from them.

    The Drobo handles everything for you. The rebuilding, RAID mode, etc. You don't really do anything. If you are unfamiliar with configuring RAID and the implications of doing it improperly or ignoring fault tolerance, the Drobo is a good bet.

    The Promise can effectively do the same with their Automatic configuration mode.

    The Drobo does have the any size drive advantage. However, this can amount to less available space overall as the Drobo is controlling the underlying structure. So while you can put in a 3TB drive, to maintain the same level of fault tolerance you may only be getting 50% of the space.

    The Pegasus gives you much more control of your drives, you could put two larger drives in and place them in their own disk array and configure them however you like. Meaning you can get as much space you want depending on how much fault tolerance you require.

    I have been using a DroboPro for over a year. My units power supply died and from there I had to wait from them to swap my unit. During that time my data was inaccessible without another Drobo. At the very least, with the Pegasus, I could get to my data if I used the same RAID controller. I also had tons of issues with Data Robotics RMA process.

    At the end of the day, I feel more in control of my storage with the Pegasus whereas I feel powerless with the Drobo. The any size drive feature has little value when you consider you have no control over how the additional space is provisioned.

    I would recommend looking over this: http://www.promise.com/media_bank/Download Bank/Utility/Pegasus User Manual (English) .pdf

    And this:
    http://www.drobo.com/how-it-works/beyond-raid.php
    Many of the features Drobo has, you aren't going to get. Such as thin-provisioning. But chances are, that stuff isn't even on your radar.


    Bottom line:

    If you want to set it, forget it and feel like your data is protected: The Drobo is better, but the Pegasus can also achieve this level of functionality.

    If you want more control and speed: The Pegasus wins hands down.

    Drobo of course has more than just DAS models, so if you are looking for NAS capability, the Peg is not an option.
     
  5. Oyvehsmir macrumors newbie

    Joined:
    Jun 5, 2012
    #5
    Bye bye Drobo

    Same story. I've used Drobos for about 4 years. I've got an old 4 bay model which I use as an offsite back up for an FS. They both clapped out at the same time and it took 3 weeks and two days for the S to rebuild a drive and the same amount of time for Drobo service to figure out why my FS kept shutting down 5 minutes after starting. The potential of losing everything scared me so much that I looked around and I'm now sitting here with my new Pegasus drives transferring all my data. I'm guessing but I'd say the data transfer is 20 times faster and they said a drive rebuild is maximum 12 hours (not 3 weeks and 2 days!). I feel like I've woken up. On a Drobo if you're rebuilding a drive and another one dies you're cactus and plus you don't really want to use the machine while it's rebuilding. That's a lot of down time and I really don't like having all my backups together in the same place. I just went through a month of looking at the two machines and hoping that thieves and fire and accident would give me a break. I've happily moved on to Pegasus and the MyMac guy set the whole thing up because I wouldn't have a clue.
     
  6. paulrbeers macrumors 68040

    Joined:
    Dec 17, 2009
    #6
    I have a Drobo 2.0 and while it is adequate for time machine back ups, I wouldn't use it for anything else (too slow). The only reason I bought it, was that that Newegg had a crazy combo deal going on one night and I got it and 3 - 2TB drives for $450 (which was about 6+ months ago when a single 2TB drives were going for $200!). I store all of my files and what not on a Windows Machine (I know I know) that has a RAID5 controller that is at least 10x faster.
     

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