Help me be a responsible but care-free computer user

August 20, 2007 5:54 PM

Maybe obvious backup question: I want to achieve: an external hard drive with an exact copy of my main drive's contents that can, in the event of my main internal drive's failure, be swapped into the machine for instant everything-as-it-was. I also want incremental backup, so that I can keep this drive constantly up to date with a daily backup process. This is a Windows XP ThinkPad laptop; I've got the external backup drive in its little case already.

I'm half wondering if this is such a basic set of requirements -- copy my drive exactly (making sure it's bootable), and then copy incremental changes -- that most backup software does it already.

The software that came with the laptop (ThinkVantage Rescue and Recovery) creates "archive files", all ~50 MB in size, that require the backup software in order to be read. This isn't going to do it for me.

I briefly looked into Acronis, but they won't even let me install the trial without registering -- through the internet, automatically, during the installation process. Can't even register by phone. (Is it too much to want to try the software before giving them permission to automatically send themselves information about myself & my system?) No deal. Also, $50 seems like a lot for such a simple-sounding piece of software, but if I have to spend that much (or more), I'm willing.

The drive came with three pieces of software, but I can't tell whether any of them will do what I want: PC Clone EX Lite (by JMicron Technology), VBTUcopy (by VIA Technology), and HDBackup (by Moai Electronics). Each of these has a short PDF document with it -- I've read through each -- but it doesn't answer my questions, just outlines the setup procedure. These seem like very bare-bones programs, based on the docs.

To clarify: if my computer's HD fails, I'd like to avoid having to install Windows on a new drive before restoring files. I want to just take out the old drive, stick in the new drive, and then pretend nothing happened (I'd just buy a new backup drive).

I'd also like to avoid having to re-clone the HD every time I want to make an incremental backup. In other words, although I'm not sure, I'm under the impression that backup software that "clones" the HD will need to copy every single file every time it runs.

Also: I've already formatted my new drive. How can I make sure it's bootable? Do I even need to worry about that at this point?

Thanks!

posted by amtho to computers & internet (35 answers total)

How can I make sure it's bootable?

Hard drives are like empty canvases, file systems are the paints. What normally happens is that you partition the hard drive (or not), then initialize it with the file system of your choice. For Windows boxen, that means NTFS. Any Windows boot CD can do this (you don't even have to install the OS).

If you want a bit-for-bit backup, you'll probably want something like Norton Ghost. It can do incremental backups (so you don't have to save each and every file... just the ones that have changed). It's sort-of the defacto standard.
posted by Civil_Disobedient at 6:20 PM on August 20, 2007

"... In other words, although I'm not sure, I'm under the impression that backup software that "clones" the HD will need to copy every single file every time it runs. ..."

True. Cloning a drive is making a bit image of it, perhaps with bare minimum alterations of the file allocation tables to handle differences in capacity between the source and target drives, and it is a low level sector by sector copy process. The advantage is that you can, generally, just plug in a cloned drive, and you'll be running from the system state at the point in time the clone copy was made. Thus, the very easy "recovery" process is the principle advantage. But since no higher level concepts (like "file" or "directory") are included in the software that clones a disk, there is no possibility to do "incremental" change copies.

An incremental backup is always going to require the last full backup, all the incremental change backups since that last full backup, uncorrupted catalog files for the full backup and for every incremental, and a restore program that understands how to copy the full backup, and apply incremental changes sequentially, to restore the final drive state. The advantage of the incremental process is that it is much faster to backup just the changes from one day to the next, and thus both back up time and media are saved. The disadvantage is the much more complicated restore process, which can take significant time to accomplish, during the restore process. Also, the failure or omission of any catalog file, or any backup file, destroys the ability to recover the drive to the last known state, if it can be recovered to any state at all.

Given your requirements, you're better off cloning your drive on a schedule you'd be willing to live with, if any one iteration of the schedule failed. Daily image creation may be necessary for some people, but you might feel OK about imaging your drive on a weekly basis, if you feel that you could lose a weeks' worth of changes, as an acceptable cost of not having to clone drives on a daily basis.

Whatever backup strategy you choose, you should also consider rotating at least a couple of sets of backup media, to provide some depth to your archives. There are a couple of reasons to do this. First, it's possible that a virus or trojan could infect your system unbeknownst to you, and you might need to go back a week or two, to get a clean system state, that you'd be comfortable restoring as a production system. Second, with multiple media sets, you have the ability to keep offsite sets of backups, giving you some protection from fire or physical damage at any one site.
posted by paulsc at 6:23 PM on August 20, 2007

Also: there's a huge difference between backup software and total disk duplication. The former is good for data files: music, movies, documents, etc. They are cheap (free, really), plentiful, and easy to use. They won't, however, allow you to create a duplicate file system (for the most part). For that you need something like Ghost.
posted by Civil_Disobedient at 6:26 PM on August 20, 2007

Amazingly enough, I was about to ask this exact same question.

Would Ghost be the best cloning software?
posted by DMan at 6:29 PM on August 20, 2007

Also, you might want to look at RAID-1. It basically does exactly what you're looking for, with the benefit that it's so dead-simple to implement that most motherboards support it by default. This would provide true disk redundancy with the added advantage of not having to wait for the archiving/restoration process.
posted by Civil_Disobedient at 6:32 PM on August 20, 2007

raid 1 doesn't make much sense for a laptop, does it?
posted by andrew cooke at 6:42 PM on August 20, 2007

Couldn't I do a clone-type process, to make a bootable drive that would just slot into the drive bay and "work", then do an incremental-type backup over that? It might back up everything the first time, then do incremental backups -- less time -- after that. That's my thinking.

Would Ghost let me do this?

I've heard that Ghost has problems... and a quick search for "Norton Ghost" on AskMetafilter confirmed this. If it's what I need, though, I guess I could give it a try...

Please, hasn't anyone done the exact same thing I'm trying to do? I just want to back up my one laptop, simply.
posted by amtho at 6:46 PM on August 20, 2007

"incremental backup" often means something different from what you describe - a "backup" of just the changes. you might be better avoiding that term.
posted by andrew cooke at 7:00 PM on August 20, 2007

andrew - I think I do mean incremental, for the backups after the first one (or two, if necessary). Just copying the files that have changed from my laptop's internal HD to the external HD, assuming the external HD already has a complete (but partially outdated) backup on it.

If it still seems that I'm confused, I'd really appreciate it if you could elaborate...

I do have some experience with backups, but in a company-wide server kind of situation (changed backup reel-to-reel tapes in my IBM co-op employment days, got it explained to me a few times by the network admin in the tiny company where I worked as one of a few programmers just after graduation). It's been a few years, but I'm pretty sure I know what I want. I just don't know whether software exists that will make it happen.
posted by amtho at 7:24 PM on August 20, 2007

Oh, when I say "do an incremental-type backup over [a previous cloning]", I'm thinking this would create the database [TBA backup software] needs to figure out what files have changed, for the future. In other words, I'd expect the first pass of my "incremental" backup would back up all files, over the cloned files, but would make it so that future backups _wouldn't_ need to copy _all_ files.

A thought - Am I wrong in thinking that I'd need to do an initial "cloning" of the drive at all? Would just making the drive bootable, then copying all the files, have the same effect? I think I'm assuming some sort of low-level Windows voodoo that maybe doesn't exist.
posted by amtho at 7:28 PM on August 20, 2007

Suggesting RAID1 or www.rebit.com
posted by iamabot at 7:33 PM on August 20, 2007

iamabot - Thanks for the suggestion for Rebit, but it doesn't look like it will make a drive for me that I can just stick into my laptop (if the current drive fails).

Is it possible to use RAID1 with an external drive? My laptop (A Thinkpad X60) only has one internal HD bay. I'm pretty sure I don't need quite this level of up-to-the-minute... I'd like a failsafe in case I accidentally [really] delete a file. I was planning to back up once a day.
posted by amtho at 7:37 PM on August 20, 2007

andrew - I just read PaulSC's comment more closely, and I think I see why you say "incremental" isn't precisely what I mean. I definitely don't want the complex restore process, but I do want the "catalog" that will note what files have changed (or it can just use the "archive" bit, whatever -- as long as it works).

What I meant was copying just changed files. I don't care whether the backup drive is a bit-by-bit exact match, just that it boots and works exactly like the currently internal drive.
posted by amtho at 7:48 PM on August 20, 2007

I think you could swing RAID in a docking station setup. Frankly, that seems a bit anal. Windows sucks after a few years. Rather than just replicate all the detritus Windows has accumulated over the years, it is a good idea, and often necessary to wipe it clean and start from scratch with a fresh install. Backing up your data is quick and easy. If the drive fails, which is not so common as it used to be, then buy a new one, reinstall and update your apps, and then copy over your backed up data. If you really need instant backup of everything, then RAID really is the way to go.
posted by caddis at 8:30 PM on August 20, 2007

Rebit gets pretty close from what you want. From the rebit FAQ:

What if I have a PC hard disk crash?
Replace the destroyed disk drive with a new disk drive. Once the new disk drive is installed into your PC, connect the Rebit and insert the Rebit Recovery CD into your CD disk drive. Turn your PC on and select from the displayed screen the point in time to which you want to restore, and Rebit will restore your entire PC to exactly like it was at that time.

If you can't wait for that 1 hour restore time, and you think you can handle Linux-style command line programs, Ghost followed by regularly running rsync on cygwin will do what you want.
posted by gmarceau at 8:48 PM on August 20, 2007

Old versions of Norton Ghost would probably have done what you needed. New versions will not, at least not directly.

Ghost has changed from a system-image tool into a system-backup tool; why they still call it Ghost, I have no idea. It does not make 'live' images anymore at all; it creates backup files, from which it can recreate your hard drive exactly. But you can't just swap and go; you have to boot up on the Ghost CD and restore from backup images.

This can be a problem, because Ghost doesn't always recognize newer hardware, meaning you can't restore a full system completely. In the case of your Thinkpad, though, you'd probably be okay, as it's pretty old and probably fully supported by Ghost.

I don't think the image-then-rsync idea will do what you want either, because files will be open on the drive, and can change during the backup, which would have an exellent chance of corrupting data. I believe the new Volume Shadow Copy service can work around this issue, but how you'd tie that in with cygwin's rsync, I have no idea.

Don't the Thinkpads come with the SuperBays? If you can live without your CD, you could just mount a second hard drive and run a RAID1.
posted by Malor at 9:59 PM on August 20, 2007

"... I don't care whether the backup drive is a bit-by-bit exact match, just that it boots and works exactly [emphasis added] like the currently internal drive."
posted by amtho at 10:48 PM on August 20 [+] [!]

Aye, the rub is the word exactly for many backup solutions. Although I rarely rejoin threads, let me do so here, to try to flesh out my previous remarks somewhat.

A backup solution which makes incremental backups works by using file system attributes, such as the archive bit, and the "last accessed" time stamp, to do its work. And like any other process running against the file system, it changes the file system by its own operation. At least the "last accessed" time stamp, and the archive bits will be updated by any backup program working at the file system level. An advantage of this approach is that you can use file data and file system metadata to make intelligent subsets of data that you need backed up, like "incremental" backups, which examine the file system metadata for the status of the "archive" bit on every file, and just copy those files whose archive bits haven't been set. Thus, using a file system aware backup program, you an backup just your important Word docs and PowerPoint presentations, on a daily basis, and leave the full system backups for a weekly scheduled task on Sunday. Very handy in the days when backup media were expensive and relatively slow. Not so important in these days of big, cheap, fast USB 2 disks.

When a file system aware backup program runs, it changes the archive bit status on files, as well as updates the "last accessed" time stamp, at least. So, a subsequent run of the same backup utility won't copy the same files again. With file system aware backup programs, every pass yields a "unique" snapshot of the file system. And if you do "incremental" backups, and then restore to another pre-formatted drive, you may well see additional user visible changes, like file creation dates, in the restored file system. If you're using incremental backups, you will have a pretty complex restore process, that you'll need to test occasionally, and you will need a copy of your recovery program, working at least in a temporary DOS mode, to recover anything at all. If any of your catalog files is lost or corrupted, you won't be able to fully restore your system. So, most people do a full backup every seven days, and incremental backups every day between the full backups, and then they only need the last full backup and however many incremental backups they made since the last full backup to do a restore. On professionally managed servers running 24x7x365, the short snapshot window of incremental backups is their main justification, particularly for systems where the backup media is tape, and multiple copy tapes will be made and distributed automatically, for physical site security, once the backups are done.

But as a personal backup strategy on laptops, it makes less sense in these days of cheap, fast external hard drives. Cloning a 40GB system via USB2 now takes less than hour. That's a full Windows install, with Office Professional, Visio, Project, a couple of medium sized MySQL databases, MySQL Server, Eclipse, Adobe Photoshop, Acrobat, some alternate Web browsers, a bunch of photos, and around 4,000 mp3 files. And Acronis and other cloning programs make this a scriptable action, that can run at 3:00 a.m., if you like. So, that's why a lot of people just clone their disks daily, now, while they sleep. It's easy, it's fast enough, and if they use 500 GB external drives, and have a couple of 'em, they can keep 10 to 20 disk images around, and even have an offsite drive with images only a week old, that they exchange weekly. The "restore" process in such cases is literally under an hour, to a new, unformatted drive. And the result will work, exactly, as to the point in time the image being restored was taken.

But, there might be a solution that combines your desire for incremental backups, with a decent imaging strategy. You could, for example, install Windows and all your programs to a system partition on your drive, and image that, say weekly, or whenever you install new programs or software updates. The contents of a system partition typically only change when programs are added, removed, or updated, or Windows itself is changed, so a weekly image of that partition is probably "good" enough, for most people, but you could certainly image that partition on any schedule you liked. In the above 40 GB laptop example system, a system partition with the programs, help files, and examples I've mentioned installed would be about 15 GB, and you could create an bit copy image of it in less than 1/2 an hour to a USB 2 hard drive.

Then, put your data files, including the photos, the 4,000 mp3 music files, the MySQL databases, all your Office docs, all your downloaded PDF files, your financial records etc., on a separate "data" partition. Do a full backup of that, say weekly, when you image the system partition, that'll take something like 1/2 hour, too. And then, do incremental backups every day, or a couple of times a day if you like, on only the data partition. Such "snapshots" should only take a minute or two, on average, to a USB 2 drive, so make as many incremental backups a day, as you like. The catalog files will only be a few hundred kilobits each, and the incremental backups will typically only be a few megabytes, at most, unless you're some kind of major Photoshop wizard.

Personally, for the additional effort involved, I just settle for a daily image of my 90 GB drive (with about 44.4 GB of space used) at 3:00 a.m., to a 500 GB external drive. I have a couple of these, each of which can store a week's worth of full disk images, and I swap them weekly with one I keep at another place I have about 30 miles from my home, for off site redundancy. So, I have at least a 14 day deep backup vault, with simple, uncomplicated restore, and off site location protection, for about $200. The only discipline involved is making sure the external drives are plugged in and turned on, and remembering to swap them with the off site one weekly.

I use EZ Gig II software that I got a year or so ago with a drive cloning kit to do the backups, but I've used Acronis and Norton Ghost to do the same things, too. If I were paying for something, now, I'd probably use Acronis. Unless you've got several hundred gigs of data, I think you'll find it's pretty hard, cost wise, time wise, and effort wise, to beat this strategy for laptop data security.

Even if I had 160GB of laptop drive data to take care of, this strategy would work well, if I could use a window of 2 to 6 a.m. daily for creating disk images, and threw another 2 500GB drives into the mix. And still, 160GB of personal data is pretty big personal data set, even in these BitTorrent happy days.
posted by paulsc at 10:28 PM on August 20, 2007 [5 favorites]

Um, have a look at this Symantec product that pretty much acheives what you want without the messiness of Ghost or the awkwardness of software-based RAID1 on a laptop. The great thing about System Recovery is that you create a boot CD and select a target disk / snapshot interval, then forget about it. When the hard drive / machine dies, you boot from the CD, point to your target, and recover to the new machine / hard drive with minimal additional intervention. OS, user files, settings, applications, etc. are all restored.

No complaints from my customers thus far, and it looked like it was going to work quite well for me before I switched my entire home network to Mac OS. :)
posted by ZakDaddy at 10:32 PM on August 20, 2007

Also voting for Acronis - it's way ahead of current Ghost. Also, its "smart" incremental mode can restore using diffs of the incremental images and is much faster than a regular serialised full+incremental sweep. Just get a big external and set Acronis to do a daily disk incremental and an hourly user data incremental.

You could edit a registry setting and drop in a modified driver to enable XP to run RAID-1 over firewire to an external ("mirrored") but this would slow down your main disk so it felt like a mid-90s drive. Not good. You could get better results from adding an eSATA drive card but unless you have PCI Express expansion this will still feel quite sluggish.
posted by meehawl at 11:32 PM on August 20, 2007

Thanks for the information, y'all.

OK, I think andrew cooke was correct when he pointed out that I wasn't using "incremental" the way that most professional sysadmins would. I really just want the backup software to know which files have changed since the last backup, and to copy only those. Using the equivalent of the "copy" command - I don't really care if the disk is a bitwise duplicate of the original, just that all the files are there, and that the Windows setup is the same.

I'm really not sure whether I need an initial "clone" of the HD; I've been assuming that that would be the only sure way to achieve a correct setup of the Windows OS. Not having the installation disks for Windows makes everything seem...more obscure, somehow (they're apparently on the laptop's HD, but protected, and who knows what options are necessary to set everything up correctly -- and anyway I don't want to mess with it).

While I can see why just doing a full disk image copy every day at 3:00 am makes sense in many cases, I'm planning to be in situations where that's not practical (traveling who-knows-where). I want to be able to finish a 2-3 hour work session, back up only my changed files super fast -- probably onto an external drive powered only by USB power, from my laptop's battery so time & efficiency matters a lot -- then power down the laptop and not worry about it until possibly the next day. I don't plan to leave the laptop plugged in, or on, all the time; I may not have the opportunity.

In the event of a HD or other failure, I don't plan to have Windows disks or other disks with me. Just the little backup drive, maybe two of them. Of course I could bring something, but I'd like to avoid that if possible.

I'm pretty sure RAID isn't what I want -- the fact is, I chose the X60 (purchased this year) because it's very small; it doesn't actually have a place for a CD/DVD drive in the laptop itself (I looked at Macs, and would've gotten one, but they didn't come this small). There is an extra drive bay (or whatever they're called), but it's in the "ultrabase" (docking station). I may not have this with me.

So, I might not have a CD/DVD drive available at all when traveling. Thus making installation of any backup/restore software, in the field, even more difficult.
posted by amtho at 4:38 AM on August 21, 2007

(sorry for not replying earlier - i was asleep - and i cannot give more help as, despite being one happy x60 owner myself, i use linux. but from the above it sounds like acronis and "incremental mode" (not the same as "incremental backups! :o) is one way to do what you want)
posted by andrew cooke at 5:54 AM on August 21, 2007 [1 favorite]

jesus reading this makes me realise how shitty computing still is in some areas (read:microsoft). Its a really simple question the OST isnt it? And look at the answers, none of whcih are simple.

Its a really good question and one i should ask myself except for regular PC harddrives, not just laptops. I've tried RAID1 and raid in desktops PC's is just a pain. This month 3 out of my 4 drives have failed (i had 2 pairs). One of my system drives is remaining and i want to clone it to another, i guess i'll have to ghost it soon.

Just cant help thinking that apple have a really nice neat solution for this. Its not difficult surely? After 25 years of using PC's i'm finally seeing the apple appeal.....! (argh I'm dead inside!)

Also cd-dvd images? Useless idea. Requires burning them all day, the drives go wrong, they dont always burn reliably and keeping them from getting scratched and ending up with a big pile of CD's blah blah, its like something from 1993.

I have an external 500GB USB disk which all my data is on. the last 500GB died with all the data. So now I have 2. In fact i'm going to have to buy another one. Oh, and a back up for that. My next 'PC' or computer will most likely include a rack mount 16 disk SATA array with 8TB. Then i'll buy another one to back that up on to. For fucks sake....
posted by daveyt at 5:58 AM on August 21, 2007

'OST' - grr I mean OP
posted by daveyt at 5:59 AM on August 21, 2007

I use a product called syncback to solve a very similar problem. There are many other solutions about there: unison, a derivative of rsync, will do similar things, free, but too complex for my needs.
posted by bonehead at 7:09 AM on August 21, 2007

By the way, what you're looking for is generally called a synchronization manager, rather than a backup program. Makes no sense to me either, but that's what it is.
posted by bonehead at 7:11 AM on August 21, 2007

bonehead - thank you for the vocabulary! It has become abundantly clear to me that I need better words to even ask this question clearly.

Will this "synchronization manager", syncback, make my, um, 'backup drive' bootable, so that I can just put the backup drive into the computer? I've not been able to determine this from reading the web site so far.

The $30 price for the advanced version seems very reasonable, if it really will do what I want.
posted by amtho at 7:36 AM on August 21, 2007

I just used Acronis Migrate in the trial mode to put a larger HD in my laptop. It wasn't that difficult. I did have to register or something.

Syncback doesn't appear to 'clone' the disk. 'Clone' is the popular marketing term for "copies everything including the master boot record that makes the backup drive bootable."
posted by jdfan at 7:53 AM on August 21, 2007

Small thing that looks like it hasn't been mentioned so far : RAID won't help you if you accidentaly delete a file - it will be gone from the RAID copy also.
posted by the number 17 at 10:10 AM on August 21, 2007

I'm pretty sure I don't want RAID. In addition to the concern that the number 17 points out, I think it would probably use too much power from my laptop & shorten battery life.

jdfan - thanks for the clarification on the definition of 'clone'.

Now I'm thinking I actually need two pieces of software -- one to clone the disk, and a second to copy changed files to the cloned disks. Does this make sense?

If there were one piece of software that would do both, that would be ideal. I'm willing to pay for one program, but not for two.

And I'm really turned off by the Acronis' registration requirement. Argh.
posted by amtho at 10:38 AM on August 21, 2007

i basically agree with paulsc that the simplest thing for you to do is to clone your disk, but wanted to mention a couple of things that haven't yet been..

microsoft has a new product coming out called Windows Home Server. I have tried out the beta and it is an incredibly slick way of keeping up to 10 PCs on a home network backed up all the time. Since you mentioned you want a solution that will work when you're traveling this probably isn't for you, but I thought I'd mention it. Keep your eyes out for units you can by some time this fall.

I use a disk cloning program called Drive Snapshot by a guy out of Germany. You can try it for 30 days and it costs 39 euro if you decide to keep it. It's got a real simple old-school interface but works really well. I've got scripts set up on all my home & work computers to to do a differential backup nightly. (Differential as opposed to incremental in that to restore I would only need the full restore plus the latest differential). It does work below the file-system level so effectively does a bit-by-bit image of the drive which is totally the way to go. I also use SyncbackSE (the pay version) to do data-file backup and you are right that it cannot clone a drive. I actually tried it but Windows always has all kinds of crazy files locked up that it cannot get to.

Another really cool feature of DriveSnapshot is its ability to mount any of your saved snapshots as a virtual drive so that you can browse back in time to find a file that you may have lost.

As I'm thinking about how you would restore this in the event of a failure, maybe it doesn't really meet your requirements...DS creates a disk image but not a cloned disk...you would need to restore the image back onto a new drive using a DOS boot disk of some sort unless you have another computer at home with which to do the restore...hmmmm. I'll have to keep thinking about this...not sure its possible with only a laptop and an external drive.
posted by jacobsee at 11:54 PM on August 21, 2007

Davyt, if 3 of 4 drives have failed within the same month, that's not normal. In fact it's freakishly improbable. Check your power supply, your heat, and your vibration damping. In a large population, fine, but for n=4, no, definitely not.

Regarding "simplicity", yes Acronis costs, but it makes backup and migration literally two or three simple clicks. In an ideal world, there would be a commoditised, open version of comparable simplicity.Maybe next year? I've also played with MS HS backup and it's pretty good and will lead to a nice bump in backup HD sales.
posted by meehawl at 11:06 AM on August 22, 2007

I've been thinking about this and here is what I would do in your situation...correct me if any of my assumptions are wrong. You say you currently have a laptop drive, and another identical drive in a USB enclosure. Let's assume 40 GB partitioned as a single C: drive. Call them A40 and B40.

I would buy one more additional USB drive. (I'm partial to something like 120GB Passport drive for $90) Call this drive C120.

Use DriveSnapshot (or Acronis?) to make an image of A40 saved onto C120. Then restore that image to B40. Now shut down the laptop and replace A40 with B40 because you want to test this and make sure it works.

Now, keep A40 or B40 at home, and for your daily backup, run a differential backup from your laptop to C120. Periodically delete old differential backups if you are filling C120 up. Weekly, plug in the B40 backup drive and re-image it using your latest differential backup. If your drive dies you'll be able to plug in a week-old copy and get back to running.

As C120 fills up, you'll eventually want to run another full backup and start at that point making differentials. It will depend how many changes you make each day as to how quickly the differential backups grow in size.

Now, how do you get back to your most recent daily backup? You'll have to buy a new 40GB drive and restore to that from your most recent differential backup.

If 120C dies, you just order a new one and start over with a full backup of A40. In the meantime you've also got B40 on the shelf as a recent backup.

This is similar to what I do for my laptop, but since I have a second computer at home, I just keep my images on my large 500GB hard drive there. If my laptop drive were to die I would probably have to get an enclosure with the new drive so that I could reimage it from my desktop computer. For you, assuming no desktop computer to run with, you'd need B40 on the shelf just to get your computer running so you could restore your most recent backup.

Thoughts?
posted by jacobsee at 1:37 PM on August 22, 2007

One more thought on timing...I would guess 2 to 3 hours to do a full backup, 15 to 20 minutes to do a daily incremental backup.

If you want a daily backup that's even faster, back up just your critical documents folders to a subfolder on C120 using Syncback, then just do the differential backup of the whole drive when you have the time.`
posted by jacobsee at 1:45 PM on August 22, 2007

15 to 20 minutes to do a daily incremental backup

oops, i should have said 'differential'
posted by jacobsee at 1:46 PM on August 22, 2007

Here's a link to gpartd which may be exactly what you want. Two clicks and full backup. It's also free.
posted by bonehead at 10:17 AM on September 6, 2007