Re: Is there a "make hole" (truncate in middle) syscall?

From: Szakacsits Szabolcs
Date: Thu Dec 04 2003 - 18:12:06 EST



On Thu, 4 Dec 2003, Rob Landley wrote:

> What are the downsides of holes? [...] is there a performance penalty to
> having a file with 1000 4k holes in it, etc...)

Depends what you do, what fs you use. Using XFS XFS_IOC_GETBMAPX you might
get a huge improvement, see e.g. some numbers,

http://marc.theaimsgroup.com/?l=reiserfs&m=105827549109079&w=2

The problem is, 0 general purpose (like cp, tar, cat, etc) util supports
it, you have to code your app accordingly.

Szaka
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