Re: Mass-Hardlinking Oops

[Tomasz Chmielewski <mangoo@wpkg.org>]

Tracy Reed wrote:
> On Tue, Oct 13, 2009 at 08:29:02PM -0400, Matteo Frigo spake thusly:
>> Chris Mason <chris.mason@oracle.com> writes:
>>
>>> Please keep in mind this is only a limit on the number of links to a
>>> single file where the links and the file are all in the same directory.
>> For the record, the nnmaildir mail backend in Gnus (an Emacs package
>> for reading news and email) creates multiple hardlinks to the same
>> file in the same directory.  I had several thousands hardlinks at one
>> time.
> 
> I just found out that my company uses BackupPC for backups. It uses
> hard links extensively:
> 
> Features include:
> 
>     * A clever pooling scheme minimizes disk storage and disk
>       I/O. Identical files across multiple backups of the same or
>       different PC are stored only once (using hard links), resulting
>       in substantial savings in disk storage and disk writes.
> 
> "clever" indeed. It creates filesystems with zillions of inodes which
> are a pain to work with.

What's hard to work with here?


> This is the sort of large storage application
> I would be looking to use btrfs for and apparently the currently
> implementation would croak.

Nope, they are created in separate directories, so no worries here.


-- 
Tomasz Chmielewski
http://wpkg.org