MSA 2312fc presents less volume space

[Vikanich]

Hi all. I have problem with MSA 2312fc.
The storage "eats" 7GB of disk space on every 100GB presented space.

I have VDISK with 6x450GB SAS disks in RAID5. When i create 100GB volume on that vdisk and map it to host(Windows2008 or ESX) they see only 93GB space. 300GB volume is presented like 279GB disk.

Is it normal ???

Please, see attached screenshots

[Stephen Kebbell · Accepted solution]

Hi,

looks like this array calculates in "Marketing" GB, instead of "Real" GB
"Marketing GB" = 1,000,000,000 bytes
"Real GB" = 1024 x 1024 x 1024 = 1,073,741,824 bytes

Now take 300,000,000,000 and divide that by 1,073,741,824:
You get 279.396 GB, which is what Windows sees.

I have no experience with the MSA2000 Arrays, so I can't say if this is normal.

Regards,
Stephen

[Vikanich]

Thank you Stephen, it looks like your calculations are absolutely correct.
Damn marketing!

[Michael Leu]

Hi Vikanich

In the web interface you can only specify GB, but if you connect over SSH it is possible to create a volume with 100GiB:

# create volume vdisk vd01 size 100GiB vd01_v000

The important bit is the "i" between GB :-)

[Michael Leu]

Hi again

I just found that you can change the Base Preference per user!

Just go to
Configuration->Users->Modify Users
and change the Base Preference from Base 10 to Base 2.

[Uwe Zessin]

Does that mean the MSA replaces
1,073,741,824
with
001,000,000,000,000,000,000,000,000,000,000
when you switch to 'base 2'?
(sorry, could not resist ;-)

[Vikanich]

Thank you Michael, I have checked everything you wrote and it works!
I setup my user account to "Base 2" and now 1TB SATA disks are shown as 930GB and presented volumes have correct size.
Key "GiB" also works.

Thank you everyone for help!