Solaris

Copying sparse files is frequently a problem. The ability to replicate sparse files holes-and-all is often not merely system-specific but filesystem-specific too. I wrote a sparsecat utility which turns space full of NULLs into sparse holes but it does it brute force -- it doesn't know where the holes originally were, it just checks for sectors full of zeroes. It's not guaranteed in any sense either.

FWIW, on Linux systems (not sure about Solaris, sorry), you can detect sparse files by comparing the output of these two commands:

Code:

du -s -B1 --apparent-size sparse-file

and:

Code:

du -s -B1 sparse-file

For twenty gigs worth of space, the difference should be apparent enough between du -h and ls -lh.

Instead of using cpio which isn't sparse file aware, use ufsdump/ufsrestore to backup your directories. Make also sure you backup stable data by either locking the filesystem (lockfs) or creating a snapshot of it (fssnap).

But... is the "df" command able to detect sparse files???, it should detect them, should it?. I am kind of confused here... if I create a 5Gb sparse file on a filesystem, lets say /u01, then

Code:

du -sh sparse-file

should say that the file is 5Gb... then if I copy the same file to another filesystem, /u02, and do the

Code:

du -sh sparse-file

, the result should be the same. Now, lets say in both filesystems: /u01 and /u02 I have only this file, the df -h command will report the same as du...

What I mean is, it doesn't matter that a sparse file is 10 Gb big and only 1 Gb of it is filled with usefull data, the df or ls -lh or du -sh commands have to return that the file is 10 Gb big.... right?!?!

A 5GB sparse file may take up only 500MB for instance. If you copy the file with a program that does not take sparse files into account, its copy will take up 5GB on the target file system.

I found the infamous 20 Gb sparse file!!! :-), you were right guys!, now I'll follow jlliagre's advice on using ufsdump/ufsrestore to do this job... I'll try:

Code:

ufsdump 0f - /dev/rdsk/c0t0d0s0 | (cd /u02; ufsrestore xf -)

and see how it goes...

Thank you to everyone for your time and help!!!

PS: I used

Code:

ls -lh filename

to see the file size (it showed 20 Gb) and

Code:

du -h filename

to see the real/actual size it is consuming (it showed 96 Kb).