[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-tar] High per file overhead?

From: Joerg Schilling
Subject: Re: [Bug-tar] High per file overhead?
Date: Sun, 26 Feb 2006 13:21:35 +0100
User-agent: nail 11.2 8/15/04

Phillip Susi <address@hidden> wrote:

> > As cpio does not offer a -H newc format, let me asume that you are talking  
> >  
> > about the -c or -H crc format...  
> >   
> Yes, it does have a newc format, see the info page.  It is also the 
> format used by the linux kernel for initramfs images.

A quick look into the cpio source 
verifies that there is no such format in cpio.

Maybe you are not talking about cpio but about one of many cpio clones.....

> > du only counts the file contend and a part of the meta data (not counting 
> > e.g.
> > the "inode" - see: /usr/include/sys/fs/ufs_inode.h)
> >   
> Right, but the timestamps, owner, and mode only take up a handful of 
> bytes, which cpio also stores.

The cpio archive format -Hcrc never has become a standard and the POSIX cpio 
has been declared obsolete 5 years ago because it it not extensible.

Less useful formats may have less overhead but this is an inferior argument
if you have to decide for a portable and extensible format. The POSIX cpio 
format is e.g. limited to 8 GB files and the SVr4 crc format is limiet to even 

If you like to have an archive format that completely fits your actual needs,
you will end up wit > 100 incompatible archive formats.

> > If you compress the result, the remaining difference is less than 1%.
> I'd say archiving my Maildir is a rather real world use, so this is 
> somewhat relevant.  I did notice though, that once compressed, the 
> difference in size is greatly diminished.

See above.


 EMail:address@hidden (home) Jörg Schilling D-13353 Berlin
       address@hidden                (uni)  
       address@hidden     (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily

reply via email to

[Prev in Thread] Current Thread [Next in Thread]