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Drobo or OWC Qx2?

dime21 said:
No, actually, they're not even close. Firewire is 73% faster than Gig-E in real world file transfer speeds.
Click to expand...

I must be in a different world. I saw similar performance between a FW800 drive on my Mac mini server as measured on the server as I got accessing the files from the server over Gig-E to my iMac. This is in transferring large files.

I do know that "Gigabit" isn't really 1 Gb/s, but it was fast enough. Of course network and server loading will make the numbers worse. In a previous job I had a gigabit connection to our server but the actual speed was such that 100BASE-T was no slower.
 
dime21 said:
No, actually, they're not even close. Firewire is 73% faster than Gig-E in real world file transfer speeds. The reason for this, is that Ethernet + TCP/IP has a massive protocol overhead, while Firewire is very lean. Also, Ethernet has way higher latency than Firewire. Lastly, Firewire transfers occur in DMA mode and do not place any load on the host CPU. Ethernet + TCP/IP do not operate in DMA mode, and will consume a measurable amount of CPU utilization.

The end result is a maximum of 78 MB/s on Firewire800, and only 45 MB/s on Gig-E in real world file transfer speeds.
Click to expand...

In this same thread, db1 (post #20) links to a NAS that did over 200MB/s. How is this possible if what you say is true?
 
dime21 said:
No, actually, they're not even close. Firewire is 73% faster than Gig-E in real world file transfer speeds. The reason for this, is that Ethernet + TCP/IP has a massive protocol overhead, while Firewire is very lean. Also, Ethernet has way higher latency than Firewire. Lastly, Firewire transfers occur in DMA mode and do not place any load on the host CPU. Ethernet + TCP/IP do not operate in DMA mode, and will consume a measurable amount of CPU utilization.

The end result is a maximum of 78 MB/s on Firewire800, and only 45 MB/s on Gig-E in real world file transfer speeds.
Click to expand...

pastrychef said:
In this same thread, db1 (post #20) links to a NAS that did over 200MB/s. How is this possible if what you say is true?
Click to expand...

Because it's not. I have two laptops each with a SSD in them. Switched Gigabit Ethernet transfers between the two on the same LAN are fully capable of maxing out the Gigabit interface at over 125 MegaBytes per second. TCP overhead is typically in the 5% range (netting ~940Mbps). With Jumbo frames, that overhead drops to ~1% netting ~993Mbps.

Furthermore, latency on any properly running Gigabit LAN is 1Ms...
 
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I am still fine with my Drobo FS over Wifi. Runs Time Machine just fine, and I store my Lightroom 3 images it is fast enough for me. 5-1tb drives with one disk redundancy enabled gives me 3.58 TB of space with only 1.2 TB used. I may upgrade the drives capacity eventually, but I am fine for now. Occasionally I backup files onto a WD My Book and take that disk to work since it is better to have some off site backup.
 
I think yesterday I finally found the perfect solution for me: Newer Technology Guardian Maximus 3TB + 3TB RAID 1 Mirror.

Looking over and over all of the RAID options, I think mirror is the best. It keeps the backup up to date every minute, which is awesome. I dont need to spend extra time doing backups to other drives. Two drives with the exact same data inside the same enclosure. Love it. Its very easy and neat.

The only doubt I have is, which I cant find on google, is how many drives can die (or fail) on RAID 1 till I lose all of the data on both drives. Does anyone know?

I mean, after one drives fails, I buy a new one and then the rebuilding process begins copying all the data to the new one. Thats perfect. But after that, what happens if another of the two drives fails a few months or years later? Do I buy a new drive again and put it inside and thats it? Or all the data is lost no matter if I put a new drive inside again?

Theoretically, I think if both drives dont die at the same time, then it can tolerate all the drive failures one by one in the world, right?

Its not like RAID 5 where after one drive failure your data stops being safe, right?

With the Guardian Maximus it doesnt matter how many drives fail, because you always have the other drive inside the enclosure with the backup, so its like an endless loop.

Am I correct? If this is true then I'll buy it with the 3TB + 3TB option (the enclosure + 2 3TB WD Caviar Green).
 
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I'll say this again, because it is clearly not sinking in - RAID is NOT a backup! This means RAID 1, RAID 5, whatever. It's not a backup!! Mirroring data, as is done with RAID 1 is NOT a backup! What happens if you delete a file? It disappears from BOTH drives immediately! No chance to 'undo,' the file is gone! A backup maintains a separate copy of your files, preferably in a different room on a different electrical circuit, if not in a different physical location. A good backup also keeps a version history of your files so that if a file is corrupted or accidentally changed, you have a chance to recover a good version of the file. RAID does neither of these things!
 
I see your point. If there is an electrical problem or disaster, then both drives would die and all the data inside too. But thats very unlikely, right?

If you dont have that sort of problem, then you may be ok. If, for example, the enclosure falls and breaks (or the power adapter breaks, the USB or FW port break too, etc), the drives inside would still be ok? Maybe then they could be put inside another similar enclosure and keep your data safe? Because the data is inside the drives, so the enclosure shouldnt be able to destroy the data by any means. Im not sure, anyway. Someone knows?

Here is my chat with OWC asking some questions:

Chat Content:

OWC: [6:39:09 PM] Welcome to our real-time support chat. How can I help you today?
ME: [6:39:09 PM] Hi. I want to buy the Guardian Maximus with 3TB + 3TB option. I would like to know how many drives can die (or fail) until all the data on both drives inside is lost. I mean, after one drive fails, what happens if another one fails too a few months later? Will all the data be lost or will the data still be safe and then copy to another new drive? Thanks.
OWC: [6:39:36 PM] A RAID 1, like the Guardian, can have one drive failure and still have the information intact.
ME: [6:40:43 PM] Yeah, but if another drive fails a few months later after the first one what happens? Will the process of rebuilding start again or will all the data be lost?
OWC: [6:42:29 PM] You should get the failed drive replaced as soon as you can. If a second drive fails you may not be able to recover the information on it.
ME: [6:45:17 PM] I didnt explained myself correctly. What I mean is, after the first drive fails, I buy a new one and put it inside the Guardian Maximus. Then the rebuilding process starts and finishs. A few months later (or even years), another of the two drives fails. What happens then? I go and buy a new one and put it inside and thats it? Or all the data is lost no matter if I replace the second failed drive?
OWC: [6:50:47 PM] Ah, if it does fail and you rebuild it again at some point in the future you would be fine. As long as you have at least one intact drive to rebuild from at any given point you are fine.
ME: [6:54:50 PM] Thats great. So its not like RAID 5, for example, where you'll lose all your data is a second drive fails? The Guardian Maximus in RAID 1 can tolerate as many drive failures if it is one by one, right? So when the first drive fails, I buy a new one the same day and put it inside replacing the dead one. The rebuilding process finishes after a day or two and all is good again. Then, a year later, another drive fails, but theres still the other drive with the backup, so I replace again the new dead drive with a new one and everything is still good. So this way it can keep forever, right?
OWC: [6:56:47 PM] Right, as long as you get the rebuild completed it will be fine if it has a single drive failure again at some point.
ME: [6:58:14 PM] Fantastic. One more question. Im also interested in the Qx2 with 12TB. I see it has also the RAID 1 option. In this case, how would it work? How much storage space will I have available if I select RAID 1 with 12TB inside?
OWC: [7:02:37 PM] The Qx2 can only do a RAID 1 with two drives so will only support a 3TB RAID 1. You could do a RAID 10, which gives you up to 6TB of storage using all four bays.
ME: [7:05:44 PM] Ok. So with RAID 10 in the Qx2 if a second drive fails would the case be similar to the previous question I asked about the Guardian Maximus? I mean, as long as I replace the dead drive with a new one and the rebuilding process completes, it doesnt matter how many drives fail as long as they are one by one?
OWC: [7:06:09 PM] Right.
ME: [7:07:12 PM] And do you know if the Guardian Maximus and the Qx2 support any 3TB drives? I would like to use them with the 3TB Western Digital Caviar Green drives.
OWC: [7:09:06 PM] The Guardian will be fine with the Green drives. I am not sure if we have tested the Qx2 with the 3TB drives, but they did work fine with the 2TB versions.
 
Yeah, you still don't have a handle on how either RAID 1 or RAID 5 works.

If you have a RAID 1 array, and 1 drive fails, you still have 1 drive working, and your data is ok. If you replace the drive, and the data syncs to the new drive ok, you now have 2 drives again. If a few months later one of the drives again fails, you are still ok, as long as you replace the failed drive, and it rebuilds ok again. If instead, you have a failure where both drives fail at the same time, your data is gone. If you have 1 drive fail, and have an error or corruption during rebuild (not uncommon), your data is gone.

If you have a RAID 5 array, it is effectively the same situation. If 1 drive fails, and you replace it, and it rebuilds ok, you are again protected. Repeat, ad infinitum. If a drive fails, and you don't replace it, a second failure causes you to lose all data. If a drive fails, you replace it, but there is an error during rebuild, you lose all data.

Obviously, there are RAID formats that can protect against more than 1 drive failure.

ME: [6:54:50 PM] Thats great. So its not like RAID 5, for example, where you'll lose all your data is a second drive fails? The Guardian Maximus in RAID 1 can tolerate as many drive failures if it is one by one, right? So when the first drive fails, I buy a new one the same day and put it inside replacing the dead one. The rebuilding process finishes after a day or two and all is good again. Then, a year later, another drive fails, but theres still the other drive with the backup, so I replace again the new dead drive with a new one and everything is still good. So this way it can keep forever, right?
Click to expand...

No, as you describe it, RAID 1 and RAID 5 work EXACTLY the same way.
 
Ok, Im getting to understand it. Its hard to decide what to do. Some options are very expensive, others are more cheap but not that neat, etc.

I didnt know that with RAID 5 you could still keep safe all the data as long as just one drive fails one at a time and theres no errors while rebuilding. Thats interesting. I thought that after one drive died, if another one died sometime in the future then all the data would be lost, no matter what.

I'll keep researching and looking for more options. The safest thing is what you say, zhenya. I would need to find a way to do the backup correctly and keeping it up to date as mostly as possible. So I guess another safe option would be two Drobo S set up with two drive failures each? One Drobo for general use and the other one would be the backup. That way you could even have two drive failures on each enclosure. What do you think? The problem would still be if there is an electrical problem or something, but that would be very unlikely to happen to both Drobos at the same time. So if one of the Drobo fails entirely, I could still have the other one.

May I ask whats your setup? Maybe I could have it the same way.

There are other things to keep in mind too, like performance and such. My whole idea is to find the best setup possible and keep it that way forever or as long as possible. I dont want to be changing my setup every three years or so.
 
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Sensamic said:
I see your point. If there is an electrical problem or disaster, then both drives would die and all the data inside too. But thats very unlikely, right?
Click to expand...

Happens all the time. I don't know if the enclosures you're looking at have batteries or not, but if the power goes out during a write it can leave the entire array corrupted. RAID cards can and do fail all the time.

Drives also fail A LOT. Google did a paper awhile back that showed the odds of multiple drives failing in a RAID-5 (or any RAID for that matter) config were much much higher than people thought. Basically the MTBF for consumer drives is bogus.

The paper: http://static.googleusercontent.com...abs.google.com/en/us/papers/disk_failures.pdf

Some analysis: http://storagemojo.com/2007/02/19/googles-disk-failure-experience/
 
Sensamic said:
I see your point. If there is an electrical problem or disaster, then both drives would die and all the data inside too. But thats very unlikely, right?
Click to expand...

Also theft and accidental deletion. Only businesses with frequent transactions that need to be recorded or accessed need redundancy. The sort of operation where any downtime costs money. I think it is fair to say that home users never need redundant disks. HOWEVER everyone that doesn't want to risk data loss needs backups. You might lose the past day or week's files, (if you aren't running a Time Machine backup as well) but at least you won't lose months or years of files.
 
So maybe another good option would be a Drobo or Qx2 as main drive connected to the Mini for Plex with all the movies and tv shows and then a few external 2TB hard drives with all the backups. One only for movies and another one only for tv shows. This way I'll have the backups and the main drive (Drobo or Qx2) would be just one big 6TB or 8TB, because its easier to have next to the Mini as there is only one power cable and for the space is better too.

I could do a backup once or twice every month.
 
As some of the later posts, Raid 1 and 5 are very similar. Raid 1 is a mirror while raid 5 is a mirror spread out over at least 3 drives. Raid 5 is faster than Raid 1 because it has more drives with data spread out.

You can have a Raid 5 with a spare also. Not sure if DROBO supports this or not, but when building a server which works the same way, you can set it up with 4 drives in a RAID 5 configuration and have the 5th one as a SPARE. So lets say that one of the 4 drives fail, you still are okay because your spare just came online and building from the dead drive. Then out of no where before you get a replacement, another dies in your Raid...you are still okay! You have two dead drives now. If you lost a 3rd one, then yes you would loose your data. But I would hope you would at least replace one of those. Once you replace them, it will rebuild one of them, and the spare will become a spare again.

THIS is the best way to have redundancy for backups. It may not be a "backup" but to protect your data with a raid, it is the best way to do it.

You can do it with a 4 raid setup as well. 3 drives raid 5 with one spare.
 
I like your suggestion nizmoz. Is there any machine out in the market that does this?

Maybe the Qx2? Or a Synology or Qnap machine?
 
I think the DROBO does when I was researching them last night. It should say Raid 5 w/hot spare supported.
 
Ok, so I've finally decided my backup strategy: a bunch of 2TB internal drives (or 3TB when they become cheaper) and the Vogayer dock with eSata and FW800. I think its the best way for me. Its a very easy setup, I can swap drives very easily when doing backups or restores and they are easier to have in the house, more easier than the big external drives. There's also no power cords or adapters too, just the ones from the Vogayer. Every drive could benefit from the FW800 of the Vogayer. Buying external drives with triple interface is more expensive. This way I even save some money.

And if in the future Macs began to use eSata or USB 3.0, I can still use the old backup drives with the Vogayer. I could buy the other Vogayer that has USB 3.0. Now Im waiting to see when they are going to release the Vogayer with support for 3TB drives.

Being this my backup strategy, now Im thinking what setup to have permanently next to the Mac Mini for Plex. A few external drives would do, they are cheap, but it would be a mess with so many cables around, so maybe I will buy the Drobo or Qx2 or something similar.

And in the future I could buy another 4 bay enclosure (or maybe 5 or 6 if they become cheaper, which I guess they will) and have it next to the Drobo or Qx2 and I could have a total of 18TB or more using 3TB drives and one drive protection.
 
Drive failure w Q2

I am going through agony after a OTC Q2 failed leaving me with reproducing 3 months of work. It failed on first night of operation and tech support said to re format. Should have sent it back. Instead I did 3 mo worth of work and it totally failed. OWC can't fix it but they would be happy to have me pay someone else to fix it. I am left with a nightmare.

Drobo working fine out of the box. Make your own choice carefully. Didn't know I would have to have a second full system to protect against OWC failure. Tech support just follows the company line and they sound so fake when they say sorry nothing we can do.
 
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Drobo Disaster

I just bought an OWC Mercury Al-Pro Qx2 after an agonizing week with a 4-bay 2nd gen Drobo. I originally bought the Drobo because I wasn't exactly sure that I wanted to invest in purchasing 4 hard drives all at the same time.

I connected the Drobo via FireWire 800 to my Mac mini and booted the unit (or attempted to). It locked up with all lights on. After pulling the power cord and plugging it back in, it booted and I was on my way to configuring the partitions. I then copied about 2 TB of data to the Drobo (again, attempted to). The Drobo locked up, leaving Finder to present a message that data could not be read/written. I attempted to reboot the Mac mini to find that when the Drobo went down, it hung the whole system.

So, by day 3, I finally get all of my data on the Drobo (whew). I go to access my Air Video Server from my iPhone...no videos found. So, I VNC in to take a look at what's going on. The Drobo unmounted itself.

So, I call Drobo Support who makes me go through the first level troubleshooting stuff that an 18-year Mac veteran has already tried. They transferred me to level 2 support who replaced the unit.

New unit comes in, move my disk pack and everything is good for about 3 days. Day 4, the Drobo unmounts as I'm encoding a video on my iMac and sending it over the network to the Mac mini which is sharing the Drobo. Pissed and at the end of my rope, I returned the unit and bought a Qx2 and two additional drives.

3 weeks into ownership, I've had no problems at all with the Qx2 and the performance is easily 3x better than the Drobo. I've transferred over 3TB of data and am currently using it live over the network at this very moment.
 
A Poor Man's DROBO/Qx2 Enclosure, Mediasonic

I've been in a similar conundrum as many who have been following this thread.
I initially wanted a DROBO, the one with FW800 and add on network capability.
The problem was its imperfections. I really wanted to like it but their was just
to much negative karma surrounding it. I also couldn't justify its high price.
Choice #2 was the OWC Qx2. I wanted to like it as much as the DROBO. The
problem was its price was also more than I wanted to spend and as a side note,
I have four OWC Mercury Elite-AL Pro Dual Bay USB/FW400/FW800 Enclosures.
Three of the enclosure have failed. The fourth hasn't been taken out of the box.
Three fan failures which OWC replaced under warranty. The OWC's like to disconnect
at the wrong times. I no longer trust them as primary HD enclosures. I was
using them sporadically but don't any more.

What's a cheap, I mean thrifty guy to do? Thats right, surf the web. I wanted an
enclosure that does pretty much what the OWC Qx2 does. That is, RAID 0, 1, 3,
5 and 1+0 (10). Not 0+1 (01). All of the four disc RAID enclosures I would find
had RAID 0+1. Many enclosure were misidentified as RAID 10 but reading
comments from people who had purchased a particular enclosure would
discover it was RAID 0+1 and not 10.

Well I get eMail from various on-line merchants and one day NewEgg was
selling the Mediasonic HFR2-S3B four bay HD enclosure with RAID 0, 1, 3,
5 and 1+0 for $119.99 (USA).

I know, I know. So I surfed around doing some do diligence and discovered
the Mediasonic does have RAID 10. You see their are several enclosures
that look exactly like the Mediasonic and list RAID 10 but they actually have
RAID 0+1. By the time I got around to ordering it it was sold out. Bummer.
So I surfed around some more and discovered the Mediasonic typically sold
for around $200 (USA).

So I waited a while trying to figure out how to get a Mediasonic for $119.99
and about a month later Newegg put it on sale again. Can you guess what I
did? You guessed right. I've been using it now for a couple a' months. It looks
like it would be more at home sitting next to a PC but Its grown on me and
I now LOVE it. It runs cool and quiet. The instruction book that comes with
the enclosure isn't anything to brag about so I recommend downloading the
manuel from Mediasonic's web site. The translation into english is a little
weak but understandable.

Four 2TB discs inhabit the mediasonic in RAID 10 using FW400 and I couldn't
be happier. So if your cheap, I mean thrifty like me, sign up for NewEgg's
eMail Blasts and wait for a mediasonic sale to show up in your mail box.

Almost forgot, the Mediasonic has USB 2.0/FW400/FW800 and eSATA.
 
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