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Drobo Replacement?

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blevins321

macrumors 68030
Original poster
Dec 24, 2010
2,768
96
Detroit, MI
Hi all,

I've had a Drobo 2nd Generation (4-bay) for about a year now. I got it because of the expandability as well as the pseudo-raid implementation. Also because it doesn't require the same firmware version and drive model among the drives.

I've consistently gotten about 10mbps write and 15-20 mbps read from the drives, but the seek time (no specific number known) must be horrid because I have trouble viewing a MKV 720p movie that is stored on the drive.

I'm using the FW800 connection to my Core i5 MBP from last summer. I tried a friend's Windows PC via USB2.0 and it got about the same results as the FW800 on my Mac. Drobo support (after waiting a minimum of 45 minutes on hold on each occurrence) has me run the same 6-hour diagnostic series on the device that always yields the same results. They say that these speeds are "within normal operations thresholds."

Could anyone tell me if these speeds are normal for a Drobo or if they are normal for comparable hard drives? If they're terrible as I suspect, can someone recommend a comparable external hub? I hope to be able to use the same drives (3x1TB WD Green and 1x1TB WD Caviar Black) in the new one, but I can replace the Caviar to be firmware-compatible for a RAID5 implementation.

Thanks!
 
reebzor

reebzor

macrumors 6502a
Jul 18, 2008
869
1
Philadelphia, PA
One of the major drawbacks of the Drobo's is the pretty abysmal speeds. Thats the reason I didn't buy one. You would be much better off with a traditional RAID enclosure. The only problems is the lack of expandability and options.

There are some RAID devices that support expandability and RAID level migration. These options are more common on NAS devices or dedicated RAID cards (which you wouldn't be able to use in a MBP), but I'm sure you could find an external enclosure with RAID and similar features.

Another piece of advice would be to ditch the Black drive in favor of another Green drive. While you can certainly mix drives of the same size in a RAID array, it is not guaranteed to perform well or be stable especially considering the drastic difference in RPM speeds (5900 vs 7200).
 
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blevins321

macrumors 68030
Original poster
Dec 24, 2010
2,768
96
Detroit, MI
OWC Option

Thanks for the tip. I figured the speeds weren't normal for an external enclosure. Has anyone out there tried the OWC Mercury?
http://eshop.macsales.com/item/Other%20World%20Computing/MEQX2KIT0GB/

It's actually cheaper than the Drobo that I bought off Amazon for $330 after rebate. And as far as switching out the Caviar for another Green, Amazon has them for $60. I checked and its the same version as I currently have; they didn't upgrade the 1tbs.

Thoughts? :)
 
pastrychef

pastrychef

macrumors 601
Sep 15, 2006
4,753
1,450
New York City, NY
It sounds to me like your Drobo is over 75% full. Based on my experience with my two Drobos, once it becomes over 75% full, it continues to slow down more and more until more capacity is added.
 
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PurdueGuy

macrumors regular
Jun 23, 2010
241
2
I have had a Drobo v2 for a few months. Do you mean mbps or MBps? (megabits or megabytes)

I'm getting about 40 MBps read (320 mbps) and 20-25 MBps (160-200 mbps) writes, which I thought was amazing.

The web specs say it can get up to 54 MB/sec read, but I haven't achieved that yet. They state 24 MB/sec write, which I am achieving.

BTW: I used AJA System Test for these values.
 
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blevins321

macrumors 68030
Original poster
Dec 24, 2010
2,768
96
Detroit, MI
@Pastrychef - I've heard that from forums too. Mine though is currently sitting at about 45% capacity, but these speed issues have persisted from the time I copied its first gigabyte over, so many months ago... ;). I also heard from forums that it degrades speed to mix file system partitions on it, but I have a Time Machine volume and the remainder in another volume; both HFS+J.

@Purdueguy - I unfortunately do mean MBps. As in it takes well over a minute to read a gigabyte from it. I daresay that I would be willing to tolerate that, but the seek speed must be absolutely terrible. I'll run the AJA test for specifics when I get home from work, but the unit cannot even keep up with playing a standard-definition video and it also takes about 5 seconds for iTunes to read a single MP3 file to begin playing.
 
A

ashman70

macrumors 6502a
Dec 20, 2010
977
13
I have three NAS devices, one from Qnap, one from Thecus and one from Netgear, my advice would be to sell the Drobo, never ever buy one again, and invest your money in a proper NAS, not an external USB/firewire hard drive enclosure. You will have to likely spend more money then what you did for your Drobo, but it will be money well spent. I can easily and daily watch 720p or 1080p video over my gigabit network off either my Thecus or Qnap NAS, they are both amazing devices and offer plenty of functionality, including expandable RAID and great performance. Another company to look into although I have no direct experience with their products is Synology.

AM
 
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PurdueGuy

macrumors regular
Jun 23, 2010
241
2
blevins321 said:
@Purdueguy - I unfortunately do mean MBps. As in it takes well over a minute to read a gigabyte from it. I daresay that I would be willing to tolerate that, but the seek speed must be absolutely terrible. I'll run the AJA test for specifics when I get home from work, but the unit cannot even keep up with playing a standard-definition video and it also takes about 5 seconds for iTunes to read a single MP3 file to begin playing.
Click to expand...

I can read of 2 GB per minute from my Drobo. I do have to wait for spinup (or something) the first time I access it, but once I've accessed it, I don't have any issues.

How full is your Drobo? What are the drive sizes? Right now, I have 3x2TB drives (yielding 4 TB usable), only 1 TB of data, and a partition size of 16 TB.
 
B

blevins321

macrumors 68030
Original poster
Dec 24, 2010
2,768
96
Detroit, MI
My configuration is 4x1TB WD drives. (3 green, 1 caviar). It's about 45% full (but the speed's been about the same since I got the thing and filled it to 15%). All 4 drives are the 4k-sector drives, and the firmware was updated when they added the compatibility for those.

4TB drives, 2.7 usable after formatting. 16tb partition size. But under 1.2Tb used space.
 
Last edited:
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PurdueGuy

macrumors regular
Jun 23, 2010
241
2
My drives are all WD20EARS. However, I started with just those drives, and the Drobo firmware was already able to handle them.
 
Q

qti

macrumors newbie
Oct 7, 2008
5
0
PurdueGuy said:
I have had a Drobo v2 for a few months.

I'm getting about 40 MBps read (320 mbps) and 20-25 MBps (160-200 mbps) writes, which I thought was amazing.

BTW: I used AJA System Test for these values.
Click to expand...

Got a Drobo v2 for a couple of weeks. Same results here through FW800. I used AJA and also checked iStat Pro while transferring files, similar results. Seems quite reasonable speed - similar speed as another external HD case I had - so so far so good.
 
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