Taking a snapshot of journal and filesystem data

spiryt · n00b Joined: 22 Feb 2004 Posts: 45

Hi Guys,

Is the there a tool that will take a snapshot of journal and filesystem data and restore it at the later date ?
I've had some bad experiences with reiserfs and ext3 and would like to prepare for the worst.
I would like to take a nightly snapshot of filesystem data, gzip it, encrypt it and e.g. save it to a server somwhere or send it via email to gmail account for example. Now I am not interested in a complete backup but only in taking a snapshot of filesystem informatiom, where the files are , file names etc... so it can be restored when a nasty power surge messes up my hard disk again. Most of the data I am intersted in preserving in case of a journal failure is not changing and just sitting on my hard drive for months at end. Any ideas ? Thanks in advance.

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

I have never looked into them, but you might wanna take a look at LVM's (logical volume management). Snapshotting should be possible, but I don't know if the kind of snapshotting you're talking about is possible.

But, on ext3, the data you're talking about resides in the superblock (and all it's backups) and in a lot of inodes. It's unlikely you will be able to recover your data with only the metadata, because the data itself will probably be damaged as well.

You could make offline backups

And, if you have a bad power grid, you could get a UPS. Are you sure you're having power surges BTW?

And, you might wanna take a look at par2. It allows you to generate parity data for files, allowing you to repair them after they have been damaged.
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spiryt · n00b Joined: 22 Feb 2004 Posts: 45

Thanks for the input, and yes I was thinking more of the "layout backup" - where the files are on the disk. Few times I had a complete failure of filesystem (software caused, not a hardware disk problem) and restoring the files with names like inode43925092309u23 is not fun at all, that's why I started thinking of a daily backups of filesystem information.

halfgaar · l33t Joined: 22 Feb 2004 Posts: 781 Location: Netherlands

spiryt · n00b Joined: 22 Feb 2004 Posts: 45

That assuption is based on fact that at least most of the files on that particular disk are simply my music collection, no alterations are made to this files for months if not years sometimes. I am not too interested in rescuing everything, but only the things I know are sitting in the same place for long periods of time.