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Can I backup multiple machines to the same drive?


I just read your latest newsletter about backing up. It spawned a question.
What differences are there to backing up a small local network? Can you back
all the workstations up to a single external hard drive? What software would
you recommend? I have a retail store with five workstations all running Windows
XP. Currently I backup the documents and settings folders to one hard drive and
then back that up to a flash drive all using Winzip. After reading your
newsletter I think maybe they should all be backed up the way you recommended
but wouldn’t that require sharing then entire hard disk and is that okay to

Actually it’s a fine thing to do, but it does have some limitations.

The good news, though, is that you don’t need to share out the entire hard
disk of every machine you’re backing up, only the backup drive itself.


The approach is actually pretty simple:

“… my approach has saved my bacon more than once.”
  • Connect the external hard drive to one of the systems on your LAN.

  • On that system (I’ll call it “machine1”) share that drive – either the root of that drive, or a folder into which the backups will be placed – with sufficient permissions such that the other machines on your LAN can all read from and write to it. Since I control all machines on my LAN I typically make it read/write to “Everyone”.

  • On each of the other machines on your LAN you’ll run a backup program and configure it to place backups on that drive. Typically, you’d reference it as \\machine1\share. You might actually want to create a sub folder for each machine you’re backing up, so perhaps something like “\\machine1\share\machine2” would be appropriate.

  • Test your backups. They should now back up across your LAN, and be placed onto that external drive.

Naturally, that’s the simple theory. In practice, you’ll need to understand you own LAN’s security situation, as well as the capabilities of your backup software. As outlined, it can actually be pretty simple.

But, as I said, there are some limitations.

First, consider well how much data you’re backing up. Backup images for four or five machines might add up quickly, and that external drive better be big enough to hold it all. If not, and you find you might need an additional drive or two, it might be time to consider just tacking those on to specific machines and letting them back up locally anyway. At the other extreme, if you’re just backing up select data and not entire images, it’s quite possible that your external drive might have more than enough room.

Second, consider the load. If all five machines start backing up large amounts of data at the same time they’re all going to be pounding hard on both your network and that external drive. A better approach would be to stagger the backups, having each machine perform its backup to that network drive at a different time over night.

Finally, consider your bandwidth. This may not be as much of an issue these days, but it can crop up. An external hard drive directly attached to a machine is going to be faster than most networks. Conversely, if you have an older 10 megabit network it’s possible that backing up across the network might take longer than you expect.

But overall it’s a very reasonable approach to consolidating backups. Most backup programs, including Acronis which I use myself, will allow you to save backup images to a network share.

It’s all very similar to what I do myself.

Each night my various and sundry PCs all backup data to a central location on my network. The backups are staggered so that they’re not all happening at the same time. Then that one central location itself does a system image backup to an external drive.

As always, there are pros and cons to any approach, but my approach has saved my bacon more than once.

I’m thinking your approach will too.

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6 comments on “Can I backup multiple machines to the same drive?”

  1. I would not recommend sharing an external (USB) drive as everytime I’ve done it I’ve had to mess around with the IRPStackSize parameter in the registry due to the dreaded “Not enough server storage is available to process this command” error messages. (Google it).
    I would say back them up to one machine and then backup that backup set to an external drive. I use the the very capable (and free) Cobian Backup along with Carbonite (for online, off-site backups).

  2. I have been backing up 3 computers for a number of years using the same external, high capacity USB drive. For convenience, I put each backup in a different directory. I used the free edition of Macrim Reflect and had no trouble. I had to use the backup a couple of times and all worked as expected.

    Although the three computers are on the same network, I’ve found it more convenient to use a local USB drive. It just seemed easier since there is no need for coordination (due to bandwidth) with other users during the backups.

    All 3 computers were replaced and all are using Win7. I am still backing them up using a single drive but am now using the Win7 backup utility.

  3. The backup software was interesting, but if I backed up using computer images, they would be much bigger and take much longer as backing up only files I created. Also, when I restore only a small number of files it is harder to find them in the image files. Image files tend to be zipped or something so it is harder to confirm what you are restoring.

    I want a program that replicates the manual “drag and drop” from one hard drive to another, but one which, unlike “drag and drop,” I can schedule. Compression is not needed and not wanted, because with a manual restore the restored file is easier to verify if it has not been modified in any way by the backup software.

    AND IF THAT SAME BACKUP PROGRAM set the backup bit, so that just the modified programs were copied by the schedule, that would be wonderful.

    I don’t want to copy program files because if a hard drive fails it is only data I created that is unique and irreplaceable. I can always store important configuration files along with such data.

    What backup software supports this approach?

    Windows XP, Vista, 7, client side or server side (linux) software.

  4. I’ve had great success using Clickfree USB harddrive to backup 3 units on home network. Drives run from 160gig to 1TB with all the software you need already on drive. It’s automatic
    just plug it in and it identifies each machine and backs up all files. Visit their website to see a howto video. Hope this helps.

  5. Huron — I have been very happy with GFI Home Backup, which does exactly what you want — non-compressed backups where only modified files are copied to the backup location.

  6. RE: Backing up several computers to a single drive.
    What about using a NAS drive connected to the router? Are they reliable? Some of the reviews I’ve read seem to indicate they can be slow.

    Depends on the device, but that’s a common use for NAS devices. (A NAS is really just a kind of PC with it’s hard drives shared out, when you think about it.)



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