Re: tar: Größe eines tar-files weicht erheblich von der Größe des getarten Ordners ab - ist das normal ?

On Mi, 12 Apr 2017, Lentes, Bernd wrote:

pc52842:~ # hexdump -C test.tar

00000000 74 65 73 74 2f 00 00 00 00 00 00 00 00 00 00 00 |test/...........| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000060 00 00 00 00 30 30 30 30 37 35 35 00 30 30 30 30 |....0000755.0000| 00000070 30 30 30 00 30 30 30 30 30 30 30 00 30 30 30 30 |000.0000000.0000| 00000080 30 30 30 30 30 30 30 00 31 31 37 37 30 34 34 33 |0000000.11770443| 00000090 35 36 36 00 30 31 30 35 35 30 00 20 35 00 00 00 |566.010550. 5...| 000000a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000100 00 75 73 74 61 72 20 20 00 72 6f 6f 74 00 00 00 |.ustar .root...| 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000120 00 00 00 00 00 00 00 00 00 72 6f 6f 74 00 00 00 |.........root...| 00000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000200 74 65 73 74 2f 68 61 6c 6c 6f 00 00 00 00 00 00 |test/hallo......| 00000210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000260 00 00 00 00 30 30 30 30 36 34 34 00 30 30 30 30 |....0000644.0000| 00000270 30 30 30 00 30 30 30 30 30 30 30 00 30 30 30 30 |000.0000000.0000| 00000280 30 30 30 30 30 32 30 00 31 31 37 37 30 34 34 33 |0000020.11770443| 00000290 35 33 36 00 30 31 31 35 35 37 00 20 30 00 00 00 |536.011557. 0...| 000002a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000300 00 75 73 74 61 72 20 20 00 72 6f 6f 74 00 00 00 |.ustar .root...| 00000310 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000320 00 00 00 00 00 00 00 00 00 72 6f 6f 74 00 00 00 |.........root...| 00000330 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00000400 68 61 6c 6c 68 61 6c 6c 68 61 6c 6c 6f 6f 6f 0a |hallhallhallooo.| 00000410 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

00002800

Aber da sind auch ein Haufen Nullen drin. Wirklich viel steht da nicht drin:

"The * indicates that all of the lines from 00000330 to 00000400 inclusive would be the same value as the 00000330 line and that keeps the output condensed for large files with long and aligned repeating sequences. "

https://www.suse.com/communities/blog/making-sense-hexdump/

Default block size bei tar ist 20. D.h. die Daten werden in 20*512 Byte großen Blöcken geschrieben. Nicht vorhandene Daten werden mit NULL aufgefüllt.

Du kannst ja mal mit der -b bzw. --record-size Option spielen.

Christian