YOU CAN FIND MY PERSONAL CALCULATOR AT : http://bit.ly/HyperflexSizingTool
If you know how to size your Cisco Hyperflex system, it’s not that hard! What is the formula ?
(((Disksize in TiB * #Disk per Node * (#Nodes -1)) / VRF) * 0.8 * Dedup * Compression
WOW ! Let’s explain a little bit :
Disksizes are in TB, but the OS see it in TiB. Let’s convert the TB to TiB, so you know how much free space you got in the OS. Right now the disksize is 1.2TB
(#Nodes -1) : This is because when there is a node failure, the data is still everywhere and the system can heal itself.
The VRF is a factor of howmany times a block is written to Hyperflex. VRF is 2 for test-dev or lab environments. The value is 3 for production environments.
0.8 = 20% space saving for NotEnoughSpace
The 20% was a value of the beginning of Hyperflex. It’s no 8% space savings for NotEnoughSpace.
Dedup and compression ration can be set to 1 if you don’t calculate with it.
For a HX220 there is a fixed HDD configuration of 6 HDD’s.
|Number of HX220 Nodes||Capacity in TiB|
With the HX240 we can add nodes or we can start with nodes with only 6 HDD’s and expand until 23 HDD’s. As long as each node has the same configuration.
|Number of nodes||#HDD per node||#HDD per node||#HDD per node||#HDD per node||#HDD per node|
|4||5.24 TiB||9.6 TiB||12.1 TiB||16.59 TiB||20.08 TiB|
|5||6.98 TiB||12.81 TiB||17.46 TiB||22.12 TiB||26.78 TiB|
|6||8.73 TiB||16.01 TiB||21.83 TiB||27.65 TiB||33.47 TiB|
|7||10.43 TiB||19.21 TiB||26.19 TiB||33.18 TiB||40.16 TiB|
|8||12.22 TiB||22.41 TiB||30.56 TiB||38.71 TiB||46.86 TiB|