What’s the safest and most cost-effective way of backing up 8TB of data?

Joseph V July 2, 2013
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I’ve got several 2 to 3TB hard disks totalling 8TB data, but the hard discs are getting a little older now. I have most data backed up also on hard discs that are getting a little bit older now, e.g. going on 4 or 5 years. Currently the hard drives are in 2 different computers.

My question is – for the purchase of my next set of backup drives, assuming that I don’t really need to house them in another computer or NAS (I’m fine with where they are right now):

What would be the best and most long-lasting media to go with (e.g. 2.5 drives, 3.5 drives of 2, 3 or 4TB), and how and where should I house them?

Is it ok to just by the hard drives and use an external ‘docking station’ to load them up, then put them in a safe place, not firing them up so frequently (maybe once a year), or is it better that they’re housed in a computer or NAS?

Or is there some other backup solution I haven’t thought of?

  1. Jan F
    July 2, 2013 at 9:17 pm

    The question is whether you want the data to be backed up per disk, (one backup disk per data disk), per computer (one backup storage for each computer) or both together.

    The most versatile solution would be a NAS with 4-6 drive each 2 or 3TB (be it a NAS enclosure, or a tower PC running Freenas).

    This way you could address all the options above.
    Backup each disk to one of the disks in the NAS
    JBOD 2 or 3 disks for each computer backup
    RAID5 to backup all data to a single location

    The downsides of this:
    - high investment costs
    - for single disks and JBOD if one drive dies all the data/backups on it is gone
    - if more than 1 drive of the RAID5 fails at the same time recovery will be a b*

    Also if your storage requirements rise you may have to start over or even invest again as not all RAID controllers support "hybrid growing" arrays where you can just "punch" in bigger drives and you never know if 'this' NAS will support future 4 or 5TB drives.

    Personally I usually start planning backup drives by estimating the data growth for the last year, then calculating how much storage I will need to cover the next 4 years and finally adding another percentile since data is getting bigger and bigger.

    I can hardly determine how much data you "generated" over the last year so let's say it took you 5 years to fill 8TB of storage, that's a growth of around 1.6TB per year. In order to last another 4 years you'd need around 15TB of storage.

    The final decision would be your budget:
    If you can afford it go for a 14-16TB storage and don't worry about the space for the following years.
    If you are on low budget buy something with ~10TB and hope you'll last the next 1-2 years without having to buy another drive.

  2. Bruce E
    July 2, 2013 at 1:57 pm

    Do you have a regular, scheduled backup plan that you are using or are you simply coping files from your source to the backup drives whenever you feel you need to?

    If you are doing backups on a scheduled plan, it is best to have them located on the network, preferably in a RAID solution (5+0 or 6+0, for performance & redundancy), but this kind of setup is expensive (2 RAID controllers, and you have either 1 or 2 disks of parity information hanging off of each RAID controller).

    If you simply copy files when you feel you need to, using a docking station (or "toaster") can work for you. I still use a 4-bay dock with one of my systems although the jobs are still scheduled. I have to monitor what is going on for the full backups, but the incrementals and differentials for 3 months all fit on a single 2TB drive (barely).

    Backing up to hard drives is a cost-effective solution, but I would stick with the 3.5" drives due to their larger capacity. Backing up to disk also allows for faster restores than other media. If you need to archive data for longer periods of time, you may want to consider setting up a tiered backup plan and archiving to tape those items that are unlikely to be required in the near term or are less likely to require restoration. You can also move "solid" items (those that will never change) to optical media and not even bother including them in full backups to reduce the amount of space required for the backups.

    For a more complete view of backups and many options availabe, you should consider reading the O'Reilly book "Backup and Recovery" by W. Curtis Preston. It's pretty much the bible for backup and recovery for IT professionals, but includes a great deal of information of use to the average user for backing up single systems and small home networks as well.

  3. Oron J
    July 2, 2013 at 1:09 pm

    Hard discs are the obvious choice in terms of price and longevity. It's much more difficult to say _what kind of hard disc_ - bare discs in a docking station, external USB (or eSATA, Firewire/Thunderbolt whatever) or drives in a NAS or some other file server.It all depends, We don't have all the information, and it's unlikely you will be able to give us the complete picture, so instead, I'll highlight the salient features of the different solutions.
    Before we start, I'd like to emphasize that not all drives are alike. There are cheap consumer drives at the one end, and high-end server drives at the other, and there is a very significant difference in reliability and longevity. WD actually make three "coloured" series (Green, Blue, Black) at different price points and with different warranties. In any event, I wouldn't recommend keeping important data on drives older than 3-5 years).

    Bare discs+docking station: cheap and flexible. If necessary, you can change your docking station to reflect available technology (e.g. replace your USB 2.0 dock with Thunderbolt). Another advantage is that you can easily move the drives to a secure location easily such as off-site, or into a safe. Indicentally, I would advise you to keep the drives in protective boxes/cases, as they are vulnerable. The main risks are that the discs are exposed, so can be harmed in transit or on insertion/removal. Also, the size of individual discs will require you to change discs during backups (depending on how your data is organised in the first place I suppose), and you may need to have one or two spare discs to allow you to organise your data in a reasonable way.

    External drives in enclosures: very similar to bare drives, but a little more robust. However, the enclosure itself may fail (with a 2.5" drive, it's usually the connector that goes first, with 3.5" drives, it may be the power supply or the connector/interface board). So, if you go for this option, make sure a) that the enclosures are easy to open and b) that the drive inside is a standard SATA drive (WD make some external drives which use a bespoke interface, other manufacturers may also do this, although I've not come across this so far). Overall, I'd probably consider the 2.5" external drives to be much better than their 3.5" counterparts (smaller, no separate power supply etc), but of course their capacity is lower and for for 8TB total storage they'd probably work out significantly more expenive.

    A multi-drive enclosure: Most of these allow you to span the volumes (i.e. to "join" the drives so that they appear as one large drive). Some, like the Drobo 5D also add redundancy (one or two drives which can be used for error correction and for rebuilding the array if a drive fails), and some (e.g. Drobo again) use a variety of techniques to increase the speed of the drives. On the downsides, they're relatively expensive, and the enclosure itself is a single point of failure (if the controller fails or is stolen, the whole set of discs is gone). Certainly the disc spanning feature, while very convenient, is a real risk to data integrity. Also, an enclosure with 4 drives or more may be more difficult to move to a safe location, coaxing you into the bad habit of leaving it near the original copies of the data, which is a really bad idea.

    NAS: these are similar to the enclosures mentioned above, except of course that they connect over the network. This means they can be kept at a more convenient location (e.g. in a different part of the building) but also that backup speed is likely to be slower (unless you have GB ethernet throughout). In terms of reliability, they vary, but the better SoHo models (e.g. Synology, QNAP, Buffalo) are very well made and again, you need to look at the various RAID configurations (mirroring/parity drive, two error correction drives etc). Price-wise they also vary, but therea are plenty of models that are not prohibitively expensive. Between multi-drive enclosures and NAS, I'd choose NAS every time for convenience and ease of access (not just backing up, but also restoring). The only exception would be if I needed very fast access to the data, but then that's external storage, not backup... Also, having a dual NAS solution, with one of the NASs backing up the other is preferable to internal mirroring in your situation, although it would obviously cost a lot!

    File server: pretty much the same as a NAS (in fact, a NAS is a type of file server). You may be able to use it for other purposes as well, but this would compromise data safety/security which in my opinion is not what you want to do with your storage.

    Cloud storage: if you're made of money... Even then, it would take forever to back up (and restore) your data unless you have very fast internet access (if you could afford 8TB cloud storage, you would possibly afford this too).

    Hybrid solution: You don't say what kind of data you have, but it's probably safe to assume some data is static (e.g. music & videos which are viewed from time to time, but don't change much), and some is dynamic (some of your documents, computer settings, software). Some large enterprises use a system where the data moves from "online backup" for data accessed recently, to "near online" for older data and finally "offline backup" for data that has not been accessed in a long time. While it is not practical to do quite this in a small setup, you may be able to simulate it by backing up your "static" data to an external drive (or as many drives as it takes), back up the rest using a scheduled backup on a NAS, and backup the most important data again using a cloud solution (either a dedicated backup service such as LiveDisk or Carbonite, or a "Sync" product like Dropbox, SugarSync or OakSpyder). This will mean that the static data backups are kept safe most of the time (since you don't need to repeat the backups to them often), and the most critical data is backed up a) regularly and b) to two different locations.

    • Chris M
      July 3, 2013 at 8:29 pm

      "WD actually make three “coloured” series (Green, Blue, Black) at different price points and with different warranties."

      they also make a Red series one. They are specifically for RAID arrays. And the price point is usually around or a little above Blue and below Black.

  4. Hovsep A
    July 2, 2013 at 8:37 am

    external hard drives can be good solution (you must take care of them), because online backup will not be free for 8TB? Internal hard drives are protected against free fall, but they can get infected by virus...