Backing up sparse files ... VM's and TrueCrypt ... etc

[Richard Pieri]

There are three answers that I can offer.

The first is "suck it up".  File-level archive tools can't tell if a file is sparse or not just by looking at the POSIX metadata.  They have to read the file and see long strings of zeros and then read it again for archiving.  There is no getting around that with general purpose tools.

The second is "suck it up".  You could do a block copy of the raw device, which doesn't care about sparse files, but copying the whole raw device is rife with problems come restore time.

The third is "suck it up".  There's always dump and restore but these are problematic in their own ways, too.

In the end, the inconvenience in backups of sparse files is the price we pay for the convenience of them not chewing up all of our disk space up front.  Personally, I try to avoid using sparse image files.  Not worth the hassle to me.  Disk is cheap.

--Rich P.