Unfortunetly the answer is no. Neither l1 nor l2 cache is dedup aware. 

The only vendor i know that can do this is Netapp 

In fact , most of our functions, like replication is not dedup aware. 

However we have significant advantage that zfs keeps checksums regardless of 
the dedup being on and off. So, in the future we can perhaps make functions 
more dedup friendly regardless of dedup being enabled or not. 

For example, thecnicaly it's possible to optimize our replication that it does 
not send daya chunks if a data chunk with the same chechsum exists in target, 
without enabling dedup on target and source. 

Best regards

Sent from a mobile device 

Mertol Ozyoney

On 07 Ara 2011, at 20:46, Brad Diggs <brad.di...@oracle.com> wrote:

> Hello,
> I have a hypothetical question regarding ZFS reduplication.  Does the L1ARC 
> cache benefit from reduplication
> in the sense that the L1ARC will only need to cache one copy of the 
> reduplicated data versus many copies?  
> Here is an example:
> Imagine that I have a server with 2TB of RAM and a PB of disk storage.  On 
> this server I create a single 1TB 
> data file that is full of unique data.  Then I make 9 copies of that file 
> giving each file a unique name and 
> location within the same ZFS zpool.  If I start up 10 application instances 
> where each application reads all of 
> its own unique copy of the data, will the L1ARC contain only the deduplicated 
> data or will it cache separate 
> copies the data from each file?  In simpler terms, will the L1ARC require 
> 10TB of RAM or just 1TB of RAM to 
> cache all 10 1TB files worth of data?
> My hope is that since the data only physically occupies 1TB of storage via 
> deduplication that the L1ARC
> will also only require 1TB of RAM for the data.
> Note that I know the deduplication table will use the L1ARC as well.  
> However, the focus of my question
> is on how the L1ARC would benefit from a data caching standpoint.
> Thanks in advance!
> Brad
> <PastedGraphic-2.tiff>
> Brad Diggs | Principal Sales Consultant
> Tech Blog: http://TheZoneManager.com
> LinkedIn: http://www.linkedin.com/in/braddiggs
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