Should I dedup?

[jonandermb]

I just performed a dedup simulation on my box and this is what I got:

Code:

Simulated DDT histogram:

bucket              allocated                       referenced         
______   ______________________________   ______________________________
refcnt   blocks   LSIZE   PSIZE   DSIZE   blocks   LSIZE   PSIZE   DSIZE
------   ------   -----   -----   -----   ------   -----   -----   -----
     1    19.3M   2.37T   2.13T   2.14T    19.3M   2.37T   2.13T   2.14T
     2    4.54M    576G    482G    483G    9.77M   1.21T   1.01T   1.01T
     4     459K   56.3G   44.6G   44.6G    2.06M    259G    204G    204G
     8    78.9K   9.72G   7.05G   7.06G     792K   97.6G   70.9G   71.0G
    16    12.3K   1.49G   1.17G   1.17G     232K   28.1G   21.7G   21.7G
    32      935    103M   56.9M   57.5M    38.5K   4.23G   2.32G   2.34G
    64      863    104M   78.6M   78.8M    68.5K   8.28G   5.97G   5.99G
   128       81   8.28M    684K    760K    15.1K   1.57G    122M    136M
   256       71   7.65M    268K    296K    26.9K   2.91G    101M    112M
   512      149   17.9M   8.40M   8.42M     111K   13.4G   6.97G   6.99G
    1K      335   39.1M   28.9M   29.1M     366K   42.9G   30.5G   30.7G
    2K        1    128K      4K      4K    2.19K    281M   8.78M   8.78M
    4K        1    128K      4K      4K    7.67K    982M   30.7M   30.7M
    8K        2    256K      5K      8K    20.1K   2.51G   49.9M   80.4M
   16K        1    128K      4K      4K    20.4K   2.55G   81.6M   81.6M
Total    24.3M   3.00T   2.66T   2.66T    32.7M   4.03T   3.48T   3.49T

dedup = 1.31, compress = 1.16, copies = 1.00, dedup * compress / copies = 1.52

I get that there is a possibility of having 1.31 dedup ratio if I activate it... right?
Now, the box is a i3 4130 (3.4 ghz) with 16 gb RAM (Of course ECC RAM) and 8 TB on a mirrorred raid0 setup (4 x 4TB disks) and no more than 3 concurrent clients connecting to it: Clients that are actually people working from their Mac Pros storing data and retrieving it from time to time. I also have a jail plugin with crashplan running on it in order to upload my files to crashplan servers.

I sincerely think the gain vs the usage the server has makes activating this worth it but I'd like a second opinion from experts :)

Thanks!

 

[Kevin Horton]

Dedup requires about 5 GB RAM per TB of storage. Are you will to buy 48 GB more RAM (and could your system support 64 GB RAM)?

 

[Ericloewe]

Should I dedup?

nope.avi

Dedup is a nasty thing to deal with when it's worth it. For 1.3x, it's really not worth it.

 

[jonandermb]

Ok! Understood.

Thanks!