Home and Links
 Your PC and Security
 Server NAS
 DVD making
 Raspberry Pi
 PIC projects
 Other projects
 Next >>

How to preserve your data using a Home Server

Backup & Synchronisation

Data Backup, Synchronisation and Recovery

What are the differences between Backup and Synchronisation ?

Backup is a process that typically packs copies of all your files into a single large compressed 'image' (in order to minimise the space occupied). The main advantage is that a new backup does not overwrite the old (unless you want it to). This means you have all the historical versions of your files. The main disadvantage is that all your individual files are packed up together within the image, which makes it very difficult if you only need to restore one or two files (rather than the entire lot).

Synchronisation is a process that maintains copies all your files in a duplicate folder on the Server. If you choose 'contribute' (rather than full synchronisation) then files you delete on your own computer are not deleted from the copy. The main advantage is that the copies on the Server can be browsed as 'normal' (and 'copy&pasted' back to your computer). Many synchronisation systems can be set to work 'in real time' (typically by defining a 'watched folder') so when you save a modified file, a copy is immediately taken. The disadvantage is no 'old version' of the file will exist (it's overwritten every time a new version is copied to the Server).

What should I do in addition to making backups ?

Make a number of System Restore Points. You should always make a Restore Point prior to installing any (commercial) software, however it's also a very good idea to make one immediately before making a system backup.

It's also a GOOD IDEA to run Malwarebytes or some other Virus checking software before performing a back-up.

What files should I backup ?

Everything. I suggest you use MS Backup for the System files and some sort of 'synchronisation' software to maintain up to date copies of your documents (which can be 'browsed' and 'drag&dropped / 'copy&pasted' rather than having to be 'extracted' and 'restored').

Why should I use MS Backup to back-up my system ?

Since home users plainly never have anything worth saving (or so Microsoft believes), Windows XP Home does not install Windows backup by default. You have to go get it from your Operating Systems Distribution CD (it's in the VALUEADD\MSFT\NTBACKUP folder, just double-click ntbackup.msi to install NTBackup).

There may be many back-up programs that are 'much better' than the Microsoft's NTBackup. They all have one MASSIVE DRAWBACK in common - the software must be installed on a working computer before you can 'restore' your backup !

Here we have the 'classic catch 22' .. to restore the back-up the PC must be fully working ... but if the PC is fully working, why do you need to restore ? ... and if it's NOT working, then you CAN'T restore !
So you reinstall XP and then install from a copy of the commercial backup software that you saved 'elsewhere'. However, chances are it will be unusable .. why ? because your Licence code is embedded in the backup that you can't get access to :-)

Microsoft Backups (.bkf file) can be restored to a PC with nothing installed (or working) but the basic MS operating system. Unfortunately, as with all things Microsoft, it's an all or nothing deal - you can restore your entire PC or none of it .. and if the BKF file is in any way corrupt, Microsoft will indeed have none of it.

Can I 'open' MS Backup files on a non-XP computer ?

Yes, but neither Vista not Windows 7 are able to open Windows .bkf files 'out of the box' (once again Microsoft's attitude toward it's home users wish to recover their old data on their newly purchased replacement PC is revealed).

Fortunately it's not difficult to 'get around' MS restrictions. So if you want to 'open' your .bkf on Vista or Win7, proceed as follows :-

1) Create a folder somewhere (call it, say, "XPbackup")
2) Copy in the following** XP files :-
ntbackup.exe, vssapi.dll, ntmsapi.dll (if you want 'help', copy ntbackup.chm and ntbackup.hlp
3) Launch ntbackup.exe, select the 'Restore' tab
4) Select Tools/Catalog then select and restore your files "to an alternate location" (using the drop-down box in the lower-left corner of the app. to specify where)

**Note = if you don't have a running XP system, then you will have to locate and 'expand' the files from your XP installation CD (they will be compacted as 'ntbackup.ex_' etc on the CD).

Help = I'm unable to 'open' my .bkf file = what can I do ?

BKF files seem amazingly easy to corrupt. Apparently the file format is based on something called MTF (Microsoft Tape Format) which you can read all about here, or download the MTS pdf from here and the slightest 'error' will result in Microsoft's backup software collapsing in a heap.

Whilst your .bkf files may contain data that is vital to you, plainly MS just couldn't care less - they just threw together some old garbage left over from the dawn of computing (anyone else remember the tape drives used with the very first computers ?) and then provided 'Restore' software that was incapable of recovering anything in the event of the slightest problem.

Fortunately an Open Source BKF (MTF) reader exists that will recover files from corrupted backups even when Microsoft's own software refuses.

What's the problem with commercial backup solutions ?

The drawback is that the compressed backup files created by any commercial software will be unreadable by Windows (if windows could read them, why would you need the commercial software ?). So, after a system crash has forced you to reformat your hard disk and re-install Windows, the next thing you will discover is that your original commercial back-up software CD is no-where to be found. Having eventually found the original CD, you will now need to install the software again ... and that's when you will get a 'your Licence is invalid or already registered' Error

What non-commercial backup solutions exist ?

If you really can't stand Microsoft's backup software, I suggest you go for one of the many free or Open Source backup offerings such as BackupPC.

What Microsoft Synchronisation software exists ?

A1. Windows has a two built-in features that can be used for synchronisation. One is the 'Briefcase (see MS Knowledge-base KB307885) and the other 'Offline Files' (see MS Knowledge-base KB307853). Both are aimed at the corporate Laptop user who wishes to ensure their 'work at home' is 'synchronised' with copies on the Corporate Server so is 'aimed' at the 'My Documents' folder etc.

Synchronisation occurs only when the network 'connection state' changes i.e.. when you turn on and connect to a 'share' or when you instruct Windows to shut down and disconnect from the share (see MS Knowledge-base KB321171). This means computers left on for long periods will not be synchronised.

NB. Offline Files is not available to XP Home users

A2. Microsoft 'SyncToy' is a basic synchronisation application, a free download from Microsoft's web site. It's main advantage is that can handle multiple folders, it's main disadvantage is lack of any 'watched folder' features (although it could be set to run as a Task (via Task Scheduler) at regular intervals thus 'simulating' a watched folder)

Note = when setting up a 'folder pair' in SyncToy, select 'CONTRIBUTE' if you want to avoid SyncToy deleting files on the Server that you deleted on your computer.

What Open Source product do you recommend ?

DirSync Pro (Open Source) is very similar to MS SyncToy, however can be set to automatically include sub-folders (which means you can 'back-up' your entire Desktop and 'My Documents' etc. by choosing the {your user name} folder in 'c:\Documents and Settings\' as the top level folder). It also generates detailed log files and incorporates it's own Task Scheduler which can be set to run every 15 mins (so, in effect, you can 'watch' the folders).

Because DirSync Pro does not include any sort of installer, it will have to be 'run' by the user. If you add it to the 'all users' Startup folder it will run automatically when any user logs-in (it does not have to launch at power-on because until some-one changes a file, there will be nothing for it to do).

FreeFileSync is manually launched Synchronisation software, which I now use on a daily basis to keep my laptop and desktop computers backed up to my NAS and 'aligned' with one another. It's very easy to use and extremely fast.

Any final words about backing up ?

Yes = Microsoft Backup lets you Schedule your backups to run at regular intervals. If your server is 'always' on, you should set up a 'schedule' to backup your system files to your 'backup share' NOW.

If your perform manual backups, you should make them a HABIT you get into. A monthly backup could be combined with some other regular monthly activity (for example, pay a bill) - or choose a fixed date (eg 1st)).

A 'full back up' of all your documents (not just the ones you 'modified in the last month') should be done at least once a year.

WARNING if you are using a DVD-R/+R for document back-ups, you MUST 'close the session' each time (you don't need to 'close the disk' = when you do, nothing else can be added). If you fail to 'close the session', the DVD will be unreadable on another PC.

Recovering from a software / Hardware failure.

How do I maximise my chances of recovering from a simple failure ?

Install the Windows Recovery Console. When you power-on and the 'Choose an Operating System' list appears, one option you should have access to is "Windows Recovery Console". If not, you will have to install it from your Windows XP System CD. Fortunately, Microsoft does a good job of explaining How to install the Recovery Console. Yep, one more thing you really need to do BEFORE your system crashes (rather than after :-) )

This lets you recover from a simple 'missing operating system' failure (which usually just means Windows has corrupted the 'boot block' on the first track of the disk).

What should I do when my MIRROR fails ?

If one disk of a pair fails, it will not be long before the second one goes. Disk technology is advancing every year, so after 5 years the chances of you finding an identical replacement for the broken one will be effectively zero. So to 'fix' a broken mirror, start by purchasing a PAIR of whatever is the cheapest 'pence per megabyte' drives on the market.

Note = perhaps the most important reason for buying a new pair is that the last thing you want to do is risk the data on your good disk whilst 'repairing' your MIRROR.

How do I repair a broken MIRROR ?

To create a new MIRROR you proceed as detailed in Building a RAID MIRROR for a new PC (i.e. boot the Clonezilla Live CD, take an 'image' of your working C: & save it onto one of the new drives, then UNPLUG your old C: and build the RAID). In this way, if anything goes wrong, you still have all your data (on the surviving original C: drive you unplugged).

Why should I avoid using external USB hard drives for backing up ?

These are often sold to laptop users on the promise of 'keeping your files secure' but are simply 'accidents waiting to happen' because an external drive is typically even LESS reliable than the one inside your laptop.

The (single) drive is typically housed in a poorly ventilated (and fan-less) case (so it constantly over-heats) and the cables (USB & power) are removed often and at random intervals (typically just as the directory is being updated) = so 'unknown format' and 'unreadable drive' is what you will get after the first few months use.

External USB hard drives almost universally use the 'FAT32' file system. Compared to NTFS, this format is very 'fragile' and will not recover from a directory update failure. NTFS is not intended for 'removable' drive use, and if you do manage to use it, likely the drive will be unreadable on any other computer.

Finally, they always sit upright, on the edge of your desk, just waiting for the slightest excuse to 'leap off' and perform a head crashing 'bounce' off your nice hard office-like floor :-)

If an external hard drive is all you can afford to go with your laptop, well it's better than nothing, but even so, you had better go find one of the many free or Open Source hard drive recovery tools (as well as reading all about recovering files from a broken BKF repository) NOW

Are Dynamic Disks (RAID) less reliable ?

They can be, since Windows will sometimes insist that a 'Dynamic' drive is 'invalid'. You can try 'Reactivate', however you can expect the usual MS joke (a "This operation is not allowed on the invalid disk pack" error). MS then offers you two choices - both of which will wipe your entire disk - "Convert to Basic" or "Reformat".

However, before letting Windows throw away your data, try manually converting it back to 'Basic'. MS will say that's 'impossible', but that's only true if you used any of the 'advanced' features of Dynamic disks (i.e. anything other than RAID).

To revert to Basic, without wiping the data, you have to manually edit 1 byte in the disk 'boot' sector. Downloaded HxD disk hex editor (freeware) & open the 'offending' disk. In sector 0, location 1C2, the value should read "42" = this means 'Dynamic' disk. Change the value to "07" (= Basic Disk), save the changes and reboot. If the first reboot fails to find the disk, a second often does.

Click 'Next >>' in the Navigation Bar (left) for a guide to Keeping your Server running.

The pages in this topic are :-

[This is the last page in the "Server NAS" topic. Use the Navigation menu, left, to select a new Top Topic]