Don Cragun <don.cragun at sun.com> wrote:
> and in the EXTENDED DESCRIPTION, where it says:
>
> "SUN.holesdata A Solaris extension to pax extended header
> keywords. Specifies the data and hole pairs
> for a sparse file.
>
...
> 49 SUN.holesdata= 0 8192 24576 32768 49152 49159
I just verified this on a recent build and it seems that Sun pax now contains
a similar conceptional problem as the GNU tar guys did introduce a few years
ago:
The size of the POSIX.1-2001 file metadata is limited to 8 GB. Putting the
hole information into the file meta data area thus limits the number of holes.
If you e.g. create a file with the maximum holyness (Block size == 8k),
you are able to archive a file of up to ~ 5 TB and aprox. 300 million holes.
I know that an archiver that is going to unpack this would need to allocate
5 GB of virtual memory to remember the hole list. Files that fall into this
category are already possible today, so this does not seem to be ready for the
future.
I recommend to fix this by moving the hole information into the file data area,
to switch to a offset/datasize notation (to reduce the size) and to write
the information as comma separated pairs.
J?rg
--
EMail:joerg at schily.isdn.cs.tu-berlin.de (home) J?rg Schilling D-13353 Berlin
js at cs.tu-berlin.de (uni)
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http://schily.blogspot.com/
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