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New Drobo with Firewire 800 Announced

Sweet !!

AliensAreFuzzy said:
http://www.engadget.com/2008/07/08/data-robotics-announces-second-gen-drobo-with-firewire-800/

I am really excited about this. I might get one of these very soon after I buy my iMac. Right now I've got about 5 external drives I'm using with no good (but still some) redundancy for my media.
Click to expand...

As a Freelance video Editor who occasionally works at home... this is great news. I also have five FW400 drives and a FW800 drive in use.

USB connectivity was the one thing that made the DROBO product unappealing to me for Editing purposes. It was a great idea, yet fell short. Now with the FW800 version, it looks as though I'll have to re-think the DROBO !!
 
they are pretty tempting now that they have firewire. I laughed when I first saw they only had usb.

BUT...anyone care to explain to my small brain on how you can have a good protection of 4 1 TB drives and only use 1 of the 4 for protection. I just dont get it.:confused:
 
Spikeanator6982 said:
they are pretty tempting now that they have firewire. I laughed when I first saw they only had usb.

BUT...anyone care to explain to my small brain on how you can have a good protection of 4 1 TB drives and only use 1 of the 4 for protection. I just dont get it.:confused:
Click to expand...

There isn't one drive that does all the 'protection.' Every piece of data on any of the 4 drives, is duplicated on at least one of the other drives. The drobo keeps track of where each piece is stored, so if one drive is lost, it can pull the needed files from the other 3 drives and reproduce the data from the old drive onto the new one.
 
Spikeanator6982 said:
they are pretty tempting now that they have firewire. I laughed when I first saw they only had usb.

BUT...anyone care to explain to my small brain on how you can have a good protection of 4 1 TB drives and only use 1 of the 4 for protection. I just dont get it.:confused:
Click to expand...

Well, it uses something waaaaaay more complex than how I'm explaining it... but essentially, one drive is used as a "parity" drive that, by running a simple operation comparing to the other drives, can determine what was on the drive that is missing. So if any one drive fails, the data is still there. And, from what I understand, if you aren't using the full capacity, the space you're not using is also used for backup, so there is even more redundancy.

They have an explaination on their website
 
fivepoint said:
There isn't one drive that does all the 'protection.' Every piece of data on any of the 4 drives, is duplicated on at least one of the other drives.
Click to expand...
I disagree with this...
If every piece of data were to be on two drives in its entirety, that would mean that your protected space would be only 1/2 your total space. This, however, is not the case. Drobo is more similar to RAID 5 than RAID 1. The useable space on a Drobo is the total amount of hard drive sapce you put into it minus the largest single drive (plus a little for overhead)
 
fivepoint said:
There isn't one drive that does all the 'protection.' Every piece of data on any of the 4 drives, is duplicated on at least one of the other drives. The drobo keeps track of where each piece is stored, so if one drive is lost, it can pull the needed files from the other 3 drives and reproduce the data from the old drive onto the new one.
Click to expand...

Yes, I realize that. but it says with 4 1 TB drives you have 2.7 TB of storage, and ~939 GB of protection.

but, seems to me, in order for every bit of the 2.7 TB to be on one other drive, you would need another 2.7TB....lol:eek:
 
They could have built in an Ethernet port rather than a droboshare add on. The add on only connects via USB, thereby limiting gigabit ether.
 
Another example of poor timing on my part. I just bought one of the old version a couple weeks ago. No I fond out I could have got that version for about $100 less. Oh well...just money!
 
Firewire 800 is so last year, eSata is the future. And would it have killed them to include ethernet? Sheesh.

Regardless, their first product had decent reviews, so I might actually consider one now with fw800.
 
I've been having problems with my current 1TB drive, in the next few weeks I will be buying one of these new DROBO's, loaded with 4 1TB drives.

Maybe then I can have some piece of mind :D
 
It's xor parity

Spikeanator6982 said:
Yes, I realize that. but it says with 4 1 TB drives you have 2.7 TB of storage, and ~939 GB of protection.

but, seems to me, in order for every bit of the 2.7 TB to be on one other drive, you would need another 2.7TB....lol:eek:
Click to expand...

It works like this - in essence not in details:

You have 4 equal "drives" - 3 of them have real data on them. For each equivalent sector the 4th drive has the exclusive-or of the bits from the other three drives stored.

So Parity-Drive = D1 xor D2 xor D3.

Now say D3 goes bad. you replace it with new-D3. To get the data back just put

new-D3 = D1 xor D2 xor Parity-Drive

and you have the original data back. This works for any drive including the parity drive. So you can get back a drive if you have all the others. More complicated versions of this basic idea are used in all RAID-5 and RAID-6 schemes. Hope this helps.
 
mrjk said:
It works like this - in essence not in details:

You have 4 equal "drives" - 3 of them have real data on them. For each equivalent sector the 4th drive has the exclusive-or of the bits from the other three drives stored.

So Parity-Drive = D1 xor D2 xor D3.

Now say D3 goes bad. you replace it with new-D3. To get the data back just put

new-D3 = D1 xor D2 xor Parity-Drive

and you have the original data back. This works for any drive including the parity drive. So you can get back a drive if you have all the others. More complicated versions of this basic idea are used in all RAID-5 and RAID-6 schemes. Hope this helps.
Click to expand...

i am still confused..and i have read up on raids, just dont get them though

ok..we have a file with 3 blocks of data-ABC

disk one gets- A written on it
disk two gets- B
disk three gets- C
what does disk four get? seems to me it would have to have all- ABC on it. ??? sorry..you can think i am stupid, bc i do. :)
 
Spikeanator6982 said:
i am still confused..and i have read up on raids, just dont get them though

ok..we have a file with 3 blocks of data-ABC

disk one gets- A written on it
disk two gets- B
disk three gets- C
what does disk four get? seems to me it would have to have all- ABC on it. ??? sorry..you can think i am stupid, bc i do. :)
Click to expand...

http://en.wikipedia.org/wiki/Raid_5#RAID_5

Drobo uses a similar technology, but is different because you can use different sized drives.
 
disk one gets- A written on it
disk two gets- B
disk three gets- C
what does disk four get? seems to me it would have to have all- ABC on it. ??? sorry..you can think i am stupid, bc i do.
Click to expand...

The short answer is some function, f(a,b,c). Normally f is the exclusive or function. See below

Spikeanator6982 said:
...anyone care to explain to my small brain on how you can have a good protection of 4 1 TB drives and only use 1 of the 4 for protection. I just dont get it.:confused:
Click to expand...

It's easy. The fourth drive contains "parity". That means if you read bit number N from all four drives you get four bits. The first three bits are your data, the fourth bit is either a 1 or a 0 that was written so that the total number of 1s is even. So if your three data bits are 111 to fourth is 1 if your data is 110 the fourth is 0. There is always either 0, 2 or 4 one bits in each group of four.

Now lets say a drive has failed. Say it's the second drive and you get 1X00. It is pretty easy to figure out the X=1 Same of the first drive had failed you read X100 and know that the failed drive must have had a 1.

I'm sure they do more than this. Likely computer a check sum on each sector at least.

Actually the system is more economical of there are five drives but then the more drives the greater chance on might fail. The bigger high end RAID boxes have hot spare drives that get automatically swapped in when a failure is detected. That way once a week or so the user replace the drives with red lights and then those become the new spares. We have a RAID system here at work that is a cabinet about 6 feet tall with something like a zillion disk drives. With that many drives on average you see many failures but the spares just kick in, until you run out.
 
ChrisA said:
The short answer is some function, f(a,b,c). Normally f is the exclusive or function. See below



It's easy. The fourth drive contains "parity". That means if you read bit number N from all four drives you get four bits. The first three bits are your data, the fourth bit is either a 1 or a 0 that was written so that the total number of 1s is even. So if your three data bits are 111 to fourth is 1 if your data is 110 the fourth is 0. There is always either 0, 2 or 4 one bits in each group of four.

Now lets say a drive has failed. Say it's the second drive and you get 1X00. It is pretty easy to figure out the X=1 Same of the first drive had failed you read X100 and know that the failed drive must have had a 1.

I'm sure they do more than this. Likely computer a check sum on each sector at least.

Actually the system is more economical of there are five drives but then the more drives the greater chance on might fail. The bigger high end RAID boxes have hot spare drives that get automatically swapped in when a failure is detected. That way once a week or so the user replace the drives with red lights and then those become the new spares. We have a RAID system here at work that is a cabinet about 6 feet tall with something like a zillion disk drives. With that many drives on average you see many failures but the spares just kick in, until you run out.
Click to expand...

Aww...Thank you. I believe I gained a wrinkle in my brain.:D

zioxide- i have/had read that before, but didnt get it. I the problem was I didnt understand parity. But thanks for trying.
 
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