Ostriig on 9/9/2010 at 02:48
I've been putting this off far too long, and I'd like to get rid of that little Win7 white flag in my quicklaunch the proper way - by solving it, not hiding it.
I've got a 250GB HDD in my computer that I use for the stuff that I'm more interested in preserving in case of a breakdown - software kits, projects archives, personal docs, savegames, emergency pr0nz, etc. Now, I've got another 250GB unit that I use in an external rack to which I manually copied that entire drive, but by now it's seriously out of date, since I only did it the one time when I set up my system back in January.
Now it's time for a refresh, and I figured I might as well set it up properly if it's possible. What I'd like is to set an automated process so that I can back up that internal HDD to the external when I plug the latter in, say maybe once every week or two. Ideally, I'd like the whole thing to work on a file index of sorts, so that the backup process doesn't only copy new or modified files from the internal to the external, but is also able to delete files from the external if they've been deleted from the internal in the meantime.
So is something of the sort that I'm describing at all possible, and if so can anyone help me with some directions on how to do it? And if it's not possible, can I get any other suggestions with regards to backing up on this external drive?
Al_B on 9/9/2010 at 06:54
Not the most "user friendly" way to do it, but I've used rsync for this quite successfully in the past. If your external drive is formatted to NTFS instead of FAT32 then you can set it up to do an incremental, rotating backup so that you have access to the state of files the last time you backed it up, the time before that, etc. Rather than each backup taking the full space it can use hard links so that files that are unchanged are shared between all backup snapshots.
(
http://users.softlab.ntua.gr/~ttsiod/win32backup.html) This page describes the general technique. You probably want to not use the scheduler in your case and I'd recommend adding a simple test to the batch file to skip directory rotation if the backup was interrupted. (e.g. create a file at the end of backup and test for its existence at the start).
As I say, it's a low-level way of doing backups but once it's set up it's a fire and forget option.
Ostriig on 9/9/2010 at 10:46
Okay, trying to wrap my head around this as it was clearly intended for people more knowledgeable in the area than me, but I think I can see one big problem right off the bat if I'm reading this right - it's set to keep two backups of the data on the external at any given time? In my case I've got a 250 gig drive to backup on a 250 external, and we're talking in excess of 200 gigs of data.
Also another minor thing, should I assume that if it's supposed to work on Vista it will do in Win7 as well?
Al_B on 9/9/2010 at 17:33
It can keep more than one backup - but anything that is unchanged from one backup to the next is "linked" rather than duplicated. Anything changed is stored in the new backup and anything deleted is removed from the new backup. Of course, there is some overhead with the directory tables and you need to allow space for the size of files that have changed.
Rather than back up the entire hard drive you may want to just back up the essentials - I don't tend to worry about backing up Windows itself and large software that is easy to install / download. The backup itself should be very quick once it's completed once, probably no more than 5-10minutes depending on how much has changed since you've backed up the last time.
You don't need to actually use that feature at all - you can keep just a single backup and as long as you have the "--delete" option specified then it will remove files you've deleted when it does a synchronisation.
The only likely issue you'll have with Windows 7 is if you use the vshadow program which allows you to make backups of in-use files. I'm not sure if the one in the page I linked to will work correctly, but I'll try it later on my Windows 7 machine. In any event, once the backup has completed you simply have a copy of your files on the external drive so you'll be able to get to them without having to run any sort of restore software.
Ostriig on 11/9/2010 at 02:06
Hm, I might be able to cut back a little more but certainly not down to 120 gig. Maybe about 150-180. And if I can keep a single backup, then it's all good anyway.
I'm leaving on holiday for a week tomorrow, so I won't be able to try this out until I come back. But I'll definitely sit down with and give it a shot once I'm back, thanks for the advice! If you do end up trying it out on Win7 let me know please, if not I'll tell you what happened in about ten days from now hopefully.
Al_B on 11/9/2010 at 09:57
Quote Posted by Ostriig
Hm, I might be able to cut back a little more but certainly not down to 120 gig
You don't need to cut it down that much. Even if you take up 200GB with the first backup, if you don't change anything the second backup may only take up 0.1GB for directory links. If you change a 1GB file then you may use up 201.1GB in total for two backups - and still have plenty of space free.
Ostriig on 14/9/2010 at 18:25
Hm, point, that does sound appealing. Still, I tend to make iterations for WIP projects manually, so I don't think there's much point in backing up the backup.
At any rate, though, thanks for the advice! I'll give this thing a try next week and see how it works out.
