GNU tar does recognize hardlinks:
 
[root@wade test]# dd if=/dev/zero of=test.fil bs=1k count=100
100+0 records in
100+0 records out
[root@wade test]# ln test.fil test1.fil
[root@wade test]# ln test.fil test2.fil
[root@wade test]# ln test.fil test3.fil
[root@wade test]# tar cf test.tar *.fil
[root@wade test]# tar tvf test.tar
-rw-r--r-- root/root    102400 2003-08-28 12:49:06 test1.fil
-rw-r--r-- root/root         0 2003-08-28 12:49:06 test2.fil link to test1.fil
-rw-r--r-- root/root         0 2003-08-28 12:49:06 test3.fil link to test1.fil
-rw-r--r-- root/root         0 2003-08-28 12:49:06 test.fil link to test1.fil
[root@wade test]# l
total 540
drwxr-xr-x    2 root     root         4096 Aug 28 12:50 .
drwxr-xr-x    7 root     root         4096 Aug 28 12:43 ..
-rw-r--r--    4 root     root       102400 Aug 28 12:49 test1.fil
-rw-r--r--    4 root     root       102400 Aug 28 12:49 test2.fil
-rw-r--r--    4 root     root       102400 Aug 28 12:49 test3.fil
-rw-r--r--    4 root     root       102400 Aug 28 12:49 test.fil
-rw-r--r--    1 root     root       112640 Aug 28 12:50 test.tar
 
- Wade
-----Original Message-----
From: Chris Hozian [mailto:chozian@booksys.com]
Sent: Thursday, August 28, 2003 12:12 PM
To: backuppc-users@lists.sourceforge.net
Subject: [BackupPC-users] Tar recognize hardlinks?


I have been copying /home/backuppc/data/pc/ dir to tape.  Though it appears that it is taking up a lot more space on tape then it does on the drive.  Does tar recognize hardlinks and only backup the file to tape once if it is hardlinked?


Chris Hozian
Systems Administrator
Information Technologies Department
Book Systems, Inc.
(256)-533-9746 ext 375
(256)-705-3484 Direct Line
chozian@booksys.com

"It's in that place where I put that thing that time." - Phreak (Hackers)