[linux-lvm] Data deduplication for Linux : lessfs

[Greg Freemyer]

On Wed, Jun 24, 2009 at 2:50 PM, Roy Sigurd Karlsbakk<roy at karlsbakk.net> wrote:
> On 24. juni. 2009, at 17.12, Mark Ruijter wrote:
<snip>
>> I am thinking about starting to work on a data deduplicating
>> blockdevice, a kernel module called blockless.
>
> If done smartly, this may perhaps be possible, but the problem is the
> filesystem's metadata. Is this going to be dedup'ed? How much will this
> take? A simple backup will update atime on all the files backed up, and
> although atime isn't always wanted or needed, the problem occurs elsewhere.
>

As of the 2.6.30 kernel a default mount option is "relatime".  That is
a relatively new mount option that drastically reduces the number of
atime updates.  ie. Not realtime, but relatime.

Greg
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