Three factors for calculating disk IOPS: 1, RAID type read and write IOPS calculation formula for different RAID types:
RAID type |
Formula |
RAID5, RAID3 |
Drive Iops=read ioPS + 4*write ioPS |
RAID6 |
Drive Iops=read ioPS + 6*write ioPS |
RAID1, RAID10 |
Drive Iops=read ioPS + 2*write ioPS |
2. The IOPS value of the hard disk type has different disk type IOPS:
Hard disk Type |
IOPS |
FC 15K RPM |
180 |
FC 10K RPM |
140 |
SAS 15K RPM |
180 |
SAS 10K RPM |
150 |
SATA 10K RPM |
290 |
SATA 7.2K RPM |
80 |
SATA 5.4K RPM |
40 |
Flash Drive |
2500 |
3, the specific business system read and write ratio two, case
1) Business requirements: 10TB FC 15K rpm storage space, meet 6000 IOPS, calculate RAID5,RAID10 How many hard drives are required?
You first need to know the percentage of read and write operations in I/O. Assume that the read/write ratio in 6000 ioPS is 2:1
The actual IOPS load for different RAID type drive drives is as follows:
RAID10: (2/3) *6000+2* (1/3) *6000= 8000 IOPS
RAID5: (2/3) *6000+4* (1/3) *6000=12000 IOPS
Depending on the IOPS value of the different hard disk types, the number of disks required is calculated:
raid10:8000/180 = 45 Blocks
raid5:12000/180 = 67 Blocks
2) A RAID5, consisting of 5 500G 10K rpm FC disks, to calculate the maximum IOPS supported by this raid and the IOPS available to the front-end application?
First 10K rpm FC disk, the IOPS of a single disk is 140, 5 disk maximum IOPS value is 700.
Assuming a read-write ratio of 2:1, the IOPS available to the front-end application are:
(2/3) *x+4* (1/3) *x = 700
2*x = The ioPS available to the front-end application is 350 for the x=350.
Calculation of Disk ioPS