Sufficient for Photo Editing?

Mark,

Drobo strikes me as being more of a "sexy" choice than the best choice. I know a number of the techie celebrities (like Leo Laporte, for example) give it a fair amount of publicity as being a very good solution, so I take that to mean that Drobo is probably a decent product that is very strategic at pumping out advertising dollars in the right places to give it good visibility.

Admittedly, I haven't compared very many *redundant* external devices so I don't quite know how to compare that to others. I think Basroil is probably right in saying that other external devices would give you more powerful RAID control over how you want to backup your data; Drobo looks to be more self-containted, giving the user less control. That probably explains why it's popular among non-techies who just want something they can set and forget....and not-so-popular among techies who want a very-finely controlled RAID unit!

As for the speeds of FW800 vs. FW400 vs. USB 2.0 vs. eSATA....as the posts above point out, it's not an exact science. On an old machine running XP Pro a few years ago, I got mixed results in the FW400 vs. USB 2.0 game. I had 2 different FW/USB externals, and results varied between devices and brands of hard drive I stuck in each....but that was running XP Pro. However, In OSX and all my different Linux distros (Red Hat, YellowDog, and Ubuntu), Firewire was exactly as Rene and Tony describe -- either the same (for small processes), faster, or considerably faster. The big advantage of USB is plug and play; I actually fried a Firewire device one time years ago when plugging it in with the device turned on.

Now that USB 3.0 is finally starting to show up in hardware, it'll be curious to see how long it takes for devices that can utilize all that thru-put to show up. But for now, I'd just get the best firewire-based external for your iMac that you can afford.

Christmas Greetings,
~Matt
(aka BeritOlam)

Tony-S wrote in post #9263200
Yes, that's pretty much it. You have to connect two SATA drives, drive about 16 screws, then connect it and power it up. OS X will see the drive as an uninitialized drive and ask you if you want to initialize (format) it. Click "OK", name it (I just use "Time Machine") and after it initializes it it will ask you if you want to use it as your Time Machine volume. The first backup is the longest since everything on your internal drive has to be backed up. After that, Time Machine does hourly incremental updates.

Keep in mind, a Time Machine volume is not bootable. If you ever have a crash or failure of your internal drive, you have to reinstall from the Installer DVD, after which it will ask you if you want to restore from a Time Machine volume. Easy peasy.

I went for this setup you recommended, Tony. On its way. I watched the video that shows us technically challenged ones how to assemble the gizmo. Ran a little under $500 from OWC with two 2TB Seagate 5900 rpm SATA II's.

Thanks so much for your help.

Thanks also to Matt (a.k.a. BeritOlam), basroil, René Damkot, RDKirk and Mastamarek. Lots of useful info and great help!

Let me point out something, though, for all the newbies about this: RAID is not a backup solution, RAID is a high-availability or high throughput solution (depending on which kind of RAID pattern you use).

Companies that cannot withstand any downtime of a service, even for a few minutes, use RAID to make sure their data is available even through a drive failure. Their systems warn in advance that one of the drives in the RAID arrays is about to fail, so their techs replace it before it fails. RAID allows one drive to be replaced without taking the storage system offline for even a moment.

That's protection against a drive failure, but it provides zero protection against data corruption coming out of the computer, like viruses. It will just corrupt twice as much data twice as fast.

A true back-up solution protects against data corruption by having at least one copy out of the process long enough for corruption to be detected and resolved. At the personal and small business level (as opposed to "enterprises"), that's best done with sequentially created copies.

If you have four drives on hand, you're better off with four sequential copies than with all four drives in a RAID array. The downtime of recovering a backup copy is not that significant for individuals and small businesses--having more than one backup copy is more important than ensuring constant availability.

RDKirk wrote in post #9269915
If you have four drives on hand, you're better off with four sequential copies than with all four drives in a RAID array. The downtime of recovering a backup copy is not that significant for individuals and small businesses--having more than one backup copy is more important than ensuring constant availability.

Interesting, RD. Can the setup I just purchased be used as sequential copies rather than in the RAID array?

I think you mean: Sufficient for HD Video Editing?

b.d.bop wrote in post #9270088
Interesting, RD. Can the setup I just purchased be used as sequential copies rather than in the RAID array?

Tony is right about some things, but saying it's NOT a backup method is wrong. The beauty of RAID 1 is that you can drop drives from the RAID whenever you want. If you want to back up the current drive, leave it in RAID 1, put the second drive in, and wait for it to finish "repairing" the RAID. When it's done, you'll have a 1:1 copy of the first drive. Then you can replace that drive with another as many times as you want. RAID in general is not a backup SOLUTION, but it can be used as a backup METHOD if you just use a bit of creativity.

But it's usually just easier to turn off raid (you can do that with the enclosure) and just copy and paste one drive into the next. RAID 1 comes in handy for boot drives and such, not so much for externals.

I didn't say it was not a backup method, I did say (with a quite deliberate choice of word) it was not a backup solution.

What I read suggested in too many forums--and in too many photographic magazine articles--is a RAID mirror array being suggested as the solution for backups. They almost never add that a mirror array provides no protection from data corruption.

Unless one knows what he's doing ("If you want to back up the current drive, leave it in RAID 1, put the second drive in, and wait for it to finish "repairing" the RAID. When it's done, you'll have a 1:1 copy of the first drive") multiple copies produced sequentially is a better backup solution, certainly better than relying on a single RAID mirror.

RDKirk wrote in post #9270187
I didn't say it was not a backup method, I did say (with a quite deliberate choice of word) it was not a backup solution.

What I read suggested in too many forums--and in too many photographic magazine articles--is a RAID mirror array being suggested as the solution for backups. They almost never add that a mirror array provides no protection from data corruption.

Unless one knows what he's doing ("If you want to back up the current drive, leave it in RAID 1, put the second drive in, and wait for it to finish "repairing" the RAID. When it's done, you'll have a 1:1 copy of the first drive") multiple copies produced sequentially is a better backup solution, certainly better than relying on a single RAID mirror.

My bad, I was almost 100% positive that you had let method slip... perhaps you corrected it just before I posted, since there is an edit time of 11:39, the same time I posted

But yea, RAID 1 can transmit data corruption if the drive if the error is anything but a damaged sector, which is increasingly uncommon thanks to better drive manufacturing. Agree 100% that it's easier just to do it the old fashion way, and there are plenty of software tools to facilitate that too.

b.d.bop wrote in post #9270088
Interesting, RD. Can the setup I just purchased be used as sequential copies rather than in the RAID array?

The enclosure is configured out of the box as JBOD - "just a big ole disk" and will treat both drives as a single drive when you initialize them. For practical purposes, Time Machine requires a volume that is larger than your working hard drive. Since you ordered an iMac with a 2 TB hard drive, you need a Time Machine volume that is larger than 2 TB. Since no such drive exists yet, you have to buy two drives that get initialized as a single drive (called a "volume" in Mac parlance). You'll be just fine using this enclosure and two drives for your Time Machine volume. It's precisely what I'm doing.

Tony-S wrote in post #9273062
The enclosure is configured out of the box as JBOD - "just a big ole disk" and will treat both drives as a single drive when you initialize them. For practical purposes, Time Machine requires a volume that is larger than your working hard drive. Since you ordered an iMac with a 2 TB hard drive, you need a Time Machine volume that is larger than 2 TB. Since no such drive exists yet, you have to buy two drives that get initialized as a single drive (called a "volume" in Mac parlance). You'll be just fine using this enclosure and two drives for your Time Machine volume. It's precisely what I'm doing.

You mean Just-a-Bunch-Of-Disks

Guys,

I agree that a 4-drive RAID device is a not full-blown backup solution. Sorry if I suggested it was one. I brought it up only because I was recently talking about this with a pro photog friend that uses one as a *partial* backup solution.

One lingering question I have is how much *real-world* worry one should have about data corruption in a RAID array! Virus corruption is an obvious one....but that type of corruption not really an issue for those of us using Mac and Linux!

I've built and used a few RAID arrays in my day, and I confess that this has never been an issue in any of the devices I've had my hand in putting together. Hard-drive failure? Yes! Data corruption? None really to speak of! I have a number of friends working in IT-related fields, guys who work day-in/day-out with RAID-type arrays. We're always talking about 'problems' that come up....and again I confess that I can't think of one conversation that ever was about non-virus-related data corruption in a RAID arrays!

It's more a curiosity question.

Depends on your user environment. In terms of user proportions, one could argue that Mac and Linux are such a small proportion of the environment that they don't amount to "the real world." At any rate, one must certainly consider virus corruption to be a major issue unless one explicitly specifies that one is talking strictly about a Mac or Linux environment.

If you have an environment of risky users (say, a college network or a college student on your network) then it can be a big problem. If you've got a tightly locked down network (and don't do any promiscuous surfing yourself), then it's less of a problem.

RDKirk wrote in post #9274839
Depends on your user environment. In terms of user proportions, one could argue that Mac and Linux are such a small proportion of the environment that they don't amount to "the real world."

Try telling the OP (and his new iMac) that he's not in "the real world"!

Not everyone has the same sort of backup needs. I would agree with you that something like a Drobo is not a full-proof backup solution....but I think for the average home user looking for a fairly simple way to secure something like photographs, it's a pretty good start.

BeritOlam wrote in post #9274898
Try telling the OP (and his new iMac) that he's not in "the real world"!

Yeah, I know, that will draw ire. But then, look at the bulk of the Mac market--academics and artists--a lot of people will also argue even those people aren't the "real world."

Windows Backup to an external drive is even simpler, much cheaper, and fully answers the mail for the average home user. RAID mirroring is a solution to a problem the average home user doesn't have.

Yes, drives fail, but the external drive isn't going to fail on the same day as the internal drive, and the average home user can live with the downtime of re-loading either. If some catastrophe (such as a flood or a direct lightning strike) did take out both drives simultaneously, it would have taken out the entire RAID mirror as well.

If the user has the wherewithal to purchase four drives, then four sequential copies with one copy rotated to a separate location would be a better plan than RAID mirroring alone.

Tony-S wrote in post #9273062
The enclosure is configured out of the box as JBOD - "just a big ole disk" and will treat both drives as a single drive when you initialize them. For practical purposes, Time Machine requires a volume that is larger than your working hard drive. Since you ordered an iMac with a 2 TB hard drive, you need a Time Machine volume that is larger than 2 TB. Since no such drive exists yet, you have to buy two drives that get initialized as a single drive (called a "volume" in Mac parlance). You'll be just fine using this enclosure and two drives for your Time Machine volume. It's precisely what I'm doing.

Tony, mine came in the "Independent" mode (all three switches OFF) where each drive appears as a separate volume. To get to "JBOD (SPAN)" mode (one large contiguous volume equal to 4 TB in this case) I had to flip switch #2 to "ON".
Does that make sense?