Author Topic: Which external HD - 2x 3TB or 1x 6TB (mirrored)?  (Read 1039 times)

Offline Rupert

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Which external HD - 2x 3TB or 1x 6TB (mirrored)?
« on: April 18, 2015, 02:34:36 PM »
I want to upgrade my external hard drive, which is used exclusively to back up my many photo images and associated files, plus all my data (which I refer to as my other stuff and includes email backup and all types of files within My Documents .. i.e. everything else that is not a photo).

I've decided that 3TB is going to be more than sufficient for my future-ready needs but I'm really torn between buying one single 3TB unit such as a Western Digital My Book, or to spend rather more and get a 6TB Western Digital My Book DUO which has the facility to arrange its two 3TB drives in RAID 1 format (i.e mirrored).

With the former, should the drive fail, I'd lose everything that was backed up there.  With the latter, should one of the drives fail, I've still got everything duplicated (mirrored) on the other drive.  It would be a simple matter to replace the crashed drive and return the unit to true RAID 1 again.

I don't think I'll be trusting automatic backups, so I'll be backing up manually on a regular basis (as now), except that with USB 3.0 it'll be far less hassle than with USB 2.0, where it takes me a whole morning (or afternoon) to back up the entire contents of my hard drive!

Personally I've never experienced any form of drive malfunction, either with my C:\ drive or any of my previous or current external drives, but I'm told it happens and I really don't want to be left in the lurch if it ever happens to me!  Therefore I would welcome any helpful comments or opinions in respect of the choices that I've given myself.

Offline Nick Peers

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Re: Which external HD - 2x 3TB or 1x 6TB (mirrored)?
« Reply #1 on: April 20, 2015, 11:17:02 AM »
Rupert,
        My personal opinion only is that I don't really trust RAID. It will protect one drive in the event the other fails, but it merely offers hardware redundancy only - if you accidentally delete a file on one drive, it's immediately wiped from the other too.

I'd go down the 2x 3TB route. It's probably more fiddly to play around with, but you have the option of using each drive independently of the other, giving you software redundancy too. You could, for example, back up to each drive alternately, so you effectively get two independent backups for the price of one. Accidentally delete a file before backing up? Simply reverse the change using the backup on the previously used drive.

Apologies for not getting back to you regarding your sleep problem. Is that still ongoing? If so, I'll take a closer look - there's a lot of errors in that log you copied and pasted!
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Offline Rupert

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Re: Which external HD - 2x 3TB or 1x 6TB (mirrored)?
« Reply #2 on: April 21, 2015, 02:02:16 PM »
Thanks for your words of advice, Nick; I appreciate it's only your personal opinion, but you're considerably more knowledgeable and experienced than I am with these things, so I'll be having a good long think before buying anything.  2x 3TB sounds like a good idea, but I do have a question you may be able to answer on that ..

Setting up one drive with its bundled software should be quite straightforward, i.e. just follow the steps and select the required options when prompted.  However, if I then plug in another identical unit for the first time, it will have the same bundled software and will similarly ask me to select my required backup parameters, won't it?  Is there a risk that one drive will confuse/be confused if they're both switched on and in use?  Or maybe because the set-up software is identical for both drives, perhaps the second one I install will automatically read the first drive's parameters and be ready for use immediately without any requirement for setting up?

As for the sleep issue, it seems only to do that once every so often these days, so I don't really see it as a problem.  My wife always has a session on the computer in the early evening (she's an eBay enthusiast, but at least it's her own money!) and, knowing that I'll want to have a last look in before closing it all down for the night, she usually selects sleep mode when she's finished.  That seems to be the time when it spontaneously 'wakes up' again without being asked.  It's done this far less frequently of late .. maybe once in 10 days or so.  It's occasionally happened to me too; I'll have selected sleep, left the room for a moment and re-entered to find the desktop up again.

I don't think I'm going to worry unduly, so unless there's something blindingly obvious in the list of errors I posted, please don't spend time unnecessarily going through every report.

Kind regards.

Offline Nick Peers

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Re: Which external HD - 2x 3TB or 1x 6TB (mirrored)?
« Reply #3 on: April 21, 2015, 02:13:07 PM »
That's good news on the sleep front. I will take a look at some point, to see if anything obvious leaps out. It occasionally happens to me too!

Re: the Western Digital drive, I see you have a choice of setup: RAID 0, which is the mirror function, or JBOD, which sets up each drive independently of each other. I'd imagine the software will therefore be able to handle seeing two independent drives (they'll show up separately in File Explorer too). Glancing through the manual suggests the built-in backup tool can only back up to a single drive at once, but you could get around this by setting that up to back up to one drive, then configuring a regular Windows backup (or File History if you're running Windows 8) that backs up to the other drive. That way you have two different types of backup to draw on, which is never a bad thing.
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Offline Rupert

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Re: Which external HD - 2x 3TB or 1x 6TB (mirrored)?
« Reply #4 on: April 23, 2015, 02:59:26 PM »
Hi Nick ... thanks again for your considered reply.

I wonder if I didn't make my query clear enough;  I was actually wondering more about the efficacy of having two completely separate but identical external hard drives - such as WD My Book 3TB - rather than the DUO type that can either be RAID0 or RAID1.

My question was more to do with my concerns about the set-up software of one drive creating some sort of confusion with the set-up software of the other drive, only at the time of installation.  It's probably quite straightforward, but I can't help but imagine that, once I've got Backup 1 all set up and installed that, as soon as I plug in the brand new Backup 2 ready to install and configure it, that there'll be a warning window that says something like 'This device is already installed' or maybe 'This device is already in use'.  Perhaps you can put my mind at ease on this point?

Once both identical WD My Books are installed and both turned on, i.e. 'in use', presumably I can name them as Backup 1 and Backup 2 if I want to?