In this article, we estimate controller’s performance of enterprise storage system NetApp FAS8080 for different workload profiles, as well as other parameters of IOPS per GHz, IOPS per GB.
All the performed calculations are based on the methodology described in the article «Methodology of IOPS Estimation».
Let’s gather all necessary information needed for a calculation.
- The frequency of processor cores – 2,8 GHz.
- The number of cores on one controller – 10.
- The number of processors on one controller – 2.
- The sum frequency calculation – 2,8x10x2 GHz = 56 GHz.
- At this stage we can get a rough estimation of IOPS for one controller. To do this, it is necessary to use the relation between the number of IOPS and sum frequency of the controller. This value is specified in the methodology (10000 IOPS / GHz). Multiply 56 GHz x 10,000 IOPS / GHz, we obtain a rough estimation 560000 IOPS per controller. Thus, the performance of a pair of controllers is equal to 1120000 IOPS. We can use these rough estimates for self-examination.
- We take information about recommended configurations of RAID groups in « FAS8xxx Best Practice Guide »:
- RAID-DP SSD are used in the configuration 14+2.
- RAID-DP SAS are used in the configuration 14+2.
- Max disk drive quantity for one pair of controllers is 1440.
In the article «NetApp FAS8xxx : a Brief Overview» it’s noted that 240 Flash drives of 400GB can be installed in the system FAS8080, сos the max quantity of Flash drives for All-Flash configuration, defined on the level of software, is 240.
For the calculation we will use 232 Flash drives in the configuration RAID-DP 14+2 and 6+2 in accordance with the recommendation of NetApp.
The estimation for max IOPS (Cache Read Miss)
Let’s set the values for the estimation:
- Read operations – 99%.
- The configuration for RAID groups of Flash drives – RAID-DP 14+2.
- The quantity of RAID groups for Flash drives – 14.
- We will use one disk group RAID-DP 6+2 for rest SSD disks.
- The configuration for RAID groups of SAS 10K drives – RAID-DP 14+2.
- The quantity of RAID groups for SAS 10K drives – 70.
- We will use one disk group RAID-DP 6+2 for rest SAS 10K disks.
The graphic representation results of calculation:
Max IOPS for one HA-pair is 939048.
Max IOPS for one controller is 469524.
The ratio of IOPS per GHz is about 8384.
The ratio of IOPS per GB is about 1,06.
Real Flash storage capacity is about 70,5 TB.
Real SAS 10K storage capacity is about 796 TB.
Let’s compare this result with a rough estimation, which we did in the beginning of this article. Then we got 560000 IOPS for one controller. The difference from the new result is about 16%.
That was a good estimation, taking into account that it had been made only on the basis of knowledge about the frequency of processor cores and their quantities on one controller.
The good reserve of CPU performance remains, so we expect that quantity of
Flash drives can be increased in the new version of software.
The IOPS estimation for DB like workload (Cache Read Miss)
The Initial parameters are the same, but the percentage of read operations is different. A typical ratio between read and write operations is equal to 70/30 for databases (OLTP workload).
The graphic representation of calculation results:
Max IOPS for one HA-pair (DB like) is 394400.
Max IOPS for one controller (DB like) is about 197200.
The ratio of IOPS per GHz is about 3521.
The ratio of IOPS per GB is 0,44.
The real capacity of disk space on Flash and SAS drives is the same.