Tuesday, March 04, 2008

Bloodless partition backup

Sometimes it may happen that a system blackbox arrives at your desk together with a person begging to do something to make it work again. It may have been hardware failure, power outage, virus or just a prank that made this panicked person pull the plug out of the outlet and shamefully accept that "I am afraid to turn it on after that!!" What should be the first reaction? Backup what is left. There are tons of backup software available, but most of it just copy files from one place to another on a regular basis. What you need in this situation is to copy a whole disk to network drive without booting the system preferably on the same hardware to avoid mounting HDDs. This is a task for disk cloning tools.

And while it seems logical to think about Acronis True Image or Norton Ghost on the second thought they are not really great when you need quick burn-and-use ISO image that they are unlikely to provide in their downloads section. So the best way is to check what open source has to offer. There are several tools:



The list of 8 product seems enough to choose one. Let me remind that we need ready-to-run Live CD capable to save partition or disk image to a remote network location. Throw out Mondo - it doesn't provide Live CD. TRK 3.2 also goes to the shelf - this very nice Boot CD doesn't include tools to backup/restore partition to a network drive. A pity. Linbox Rescue Server - free GPLed version can't backup NTFS partitions - won't work. FOG - project named "Free Ghost" doesn't have Live CD! and even with such promising name is designed solely for distributing the same disk image to multiple workstations over the network. Removed. So what is left:




After browsing these sites for a bit the first intention was to get rid of tools with ugly web-pages and short feature list. And it is where g4u beats them all. How can two floppy images in total 3Mb long compete with the raw power of 90Mb image of Clonezilla? Well, let's see. It was very easy to download and run g4u 2.3 from VirtualBox. Boot message gives almost all necessary information to go on except it doesn't say that you need user "install" on your FTP server. FTP is the only supported method for upload/download, but it's ok. Because of simplicity this tool had all the chances to be the chosen one of this review. Even in Windows you can easily setup FTP server given Far Manager, Python and this plugin. g4u is a tool that does the job of backing up partition, whole drive and compressing it via GZIP, but!:

1. There is no command history - and you have to retype whole command every time you've made a mistake
2. There is no anonymous FTP login option - extra hassle to setup "install" FTP user
3. Empty password is not allowed
4. No progress bar with total MB/percentage completed, not speaking about estimated time
5. Rather obscure GZIP option, which basically means compression level (default is 9 - the biggest)

To end up with g4u - an ideal approach for this awesome and minimal tool with limited usability would be to grow its ISO to 10Mb disk image by including Python and provide some wizards in .py

Next is Clonezilla - wizard interface. No FTP. Only SSH, SAMBA or NFS server that needs to be mounted for an image file. For folks without Linux experience the most complicated stuff is probably to understand "mount clonezilla image directory" dialog which basically means to attach "share" where image files can be stored (sorry for the lame comment). Saving partition image worked like a charm - not only it displayed progress window, but also detected space in use! and saved only used part. Magic! I just wonder if I'll be able to restore image manually in case Clonezilla fails. In directory with image file there are text files with disk and partition parameters, but image file itself is in custom format. In case of NTFS system - in ntfsclone 2.0 To conclude - Clonezilla version 1.0.9-10 CD is nice and usable, but a single mistake during wizard requires to start the process anew. Let's skim over alternatives.

Ghost for Linux - doesn't have its own web-page - only standard SourceForge project template, but provides ISO image for downloads. The project itself is similar to g4u - the same FTP upload method with compression, but much better interface. Version 0.24 is GPLed and Linux-based. In comparison g4u is BSD-licensed and NetBSD-based. Ok, about the contents. Multiple boot options varied mostly by linux kernel. Weird. I do not want to try every one to find out which of them will do the job. Good reference is shown right after startup documenting two options, but lazy one would prefer only the first - to enter "g4l" at command line to start wizard interface. This preferably could be just one line reminder before the system proposes shell. The nice thing about g4l wizards is that they allow to go back to correct options. Nevertheless, the real test failed on VirtualBox, because there was no default 'img' directory on FTP, and even though g4l created it, it hung afterwards. After manual restart and mkdir 'img' on FTP the process successfully completed. It can be FTP or VirtualBox bug - no idea, but with this minimal correction the test passed. Resume: setup is minimal and intuitive, though partition selection doesn't give any info about partition type. Ideal for FTP backup, but for other network access types I would still prefer Clonezilla. g4l like Clonezilla includes ntfsclone utility for NTFS backup, but its version is slightly outdated and should be selected explicitly. If you remember - there is no partition information displayed.

PartImage doesn't have its own Live CD, but seems to be the tool of choice used on PING "Backup and Restore Disk Partitions" Live CD and on SystemRescueCd. PING 2.01.10 is even more simple than Clonezilla, includes wizard interface, for network storage supports only SMB shares and requires that a predefined set of directories is already created in the destination share. This predefined set is only described on official site and that's strange, because Clonezilla manages to create all required directories automatically. So PING is not an option for burn-and-boot solution. Another annoyance is that Alt-Tab pressed within VirtualBox ends PING session prematurely. Too bad. Let's see the last one. At last!

SystemRescueCd is a whole bunch of useful tools for plumbing works. However, even with the nice help displayed at startup knowledge of *nix and the tools is still required. If I haven't used Clonezilla or g4l I had no chance to know that I needed ntfsclone. In addition I must admit I still do not remember what cmd I have to type to mount SMB share. SystemRescueCd may be the best Rescue Live CD, but it is not as convenient and intuitive as more specialized tools. As a typical lame windows user I've failed to use it properly. I.e. for backup, but there is still awesome utility named 'gparted' for disk partitioning that I would recommend to everyone. In fact there is a very awesome project that combines SystemRescueCD and Clonezilla Live CD in one disk. Grab it here - you won't regret. =)

The verdict.
To backup your disk or partition via SSH, SAMBA or NFS use Clonezilla. For convenient backup to FTP use g4l.

That's all. Enjoy!