Ask Slashdot: Asynchronous RAID-1 Free Software Backup For Laptops?

First time accepted submitter ormembar writes "I have a laptop with a 1 TB hard disk. I use rsync to perform my backups (hopefully quite regularly) on an external 1 TB hard disk. But, with such a large hard disk, it takes quite some time to perform backups because rsync scans the whole disk for updates (15 minutes in average). Does it exist somewhere a kind of asynchronous RAID-1 free software that would record in a journal all the changes that I perform on the disk and replay this journal later, when I plug my external hard disk on the laptop? I guess that it would be faster than usual backup solutions (rsync, unison, you name it) that scan the whole partitions every time. Do you feel the same annoyance when backing up laptops?"

TimeMachine

[Anonymous Coward]

Just buy a mac :-)

Re:TimeMachine

[BitZtream]

Wouldn't solve his problem. TimeMachine takes considerable time to prep and start a backup before it starts actually doing any work, I'd guess its likely doing the same sort of thing that Rsync, gathering a list of changes.

Re:find & diff

[rrohbeck]

How is traversing the whole directory tree with find different from what rsync does?
Running a daemon that lists modified files using inotify might work.

OS?

[ralf1]

The OP doesn't mention which OS he's on - the tools he mentions both run across multiple OS's. Would be helpful to know. I know as a group we probably assume some form of Linux but..... I use MS Home Server at the house to back up my family's multiple Windows machines. Runs on crappy hardware, does incrementals on a schedule, allows file level or bare metal restore, keeps daily/weekly/fulls as long as I ask it to. I know we aren't a Windows friendly crowd but this product does exactly what it promises and does it pretty well.

Just use Windows Backup

[benjymouse]

Windows Backup (since Vista) use Volume Shadow Copy (VSS) to do block level reverse incremental backup. I.e. it uses the journaling file system to track changed Blocks and only copies over the changed Blocks.

Not only that, it also backs up to a virtual harddisk file (VHD) which you can attach (Mount) as a seperately. This file system will hold the complete history, i.e. you can use the "previous versions" feature to go back to a specific backup of a directory or file.