1. Relationship between disk speed and IOPS:
| Disk Speed |
Random IOPS |
Remarks |
| 15,000 |
150 |
Each disk |
| 10,000 |
110 |
Each disk |
| 5,400 |
50 |
Each disk |
2. Raid loss
| RAID Level |
Write Cost |
| 0 |
1 |
| 1 or 10 |
2 |
| 5 |
4 |
3. General active iops
| Activity |
IOPS |
| Startup |
26 |
| Logon |
12.5 |
| Working |
8 |
| Logoff |
10.7 |
4. IOPS demand CalculationIOPS requirement = number of virtual machines * The IOPS required by each virtual machine. We can calculate the IOPS requirements for terminal login virtual machines based on frequent login scenarios, and concurrently log on to the IOPS of virtual machines. For example, if the IOPS requirement for starting a VM is 12.5, and there are 40 VMS in total, the total IOPS is 40*12.5 = 500 IOPS.
5. Calculate the number of disks required for different types of Disks Based on the disk IOPSWe need to know the total IOPS, that is, the number of disks * IOPS of each disk. For example, the total IOPS of 6 15 k sas is 6*150 = 900 IOPS. In addition, we also need to know the user's read/write ratio. Generally, we calculate the read ratio by 80% and the write ratio by 20%. The actual IOPS calculation method is: Total IOPS * write ratio)/raid loss + total IOPS * read ratio) the actual IOPS of the above example is calculated by raid10): 900*20%)/2 + 900 * 80% = 810. therefore, we have 810> 500. Therefore, when users log on normally, the raid 10 with 6 hard disks can meet their requirements. However, if the virtual machine is shut down and it takes 26*40 to log on, more than 1000 IOPS will be required. You need to add hard disks to meet your requirements.
6. Test and shareFor example, if the 40 VMS mentioned above are logged on when they are disabled, and the raid 10 is performed on 6 disks, it takes about 10 minutes to log on to the system.
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