- Pre-migration evaluation
Test the TCP speed from a source server to the target server.
where
- T: the migration time, in hours
- C: the total data volume of the source server, in GB
- S: the TCP speed (in Mbit/s) from the source server to the target ECS
- U: the network usage, which is related to network quality (jitter, delay, and packet loss). The value is usually between 0.5 and 0.8
For example, if the total data volume of the source server is 100 GB, the TCP speed tested by iPerf is 100 Mbit/s, and the network usage is 0.7, the migration time is calculated as follows:
Migration time T = 100 (GB) × 1,000 × 8/100 (Mbit/s)/3,600/0.7 ≈ 3.17 hours
You can refer to Table 1 to check the migration time of source servers of different data volumes and TCP speeds assuming that the network usage U is 0.7.
Table 1 Estimated migration duration Total Data Volume on Source Server (C) (GB)
TCP Speed (S) (Mbit/s)
Migration Time (T) (Hour)
NOTE:For migration time T, if the unit is hour, two digits are retained after the decimal point. If the unit is min, the value is an integer.
10 GB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
SMS is not recommended.
5 Mbit/s
6.35 hours
10 Mbit/s
3.17 hours
100 Mbit/s
0.32 hours (about 19 minutes)
500 Mbit/s
0.06 hours (about 4 minutes)
1,000 Mbit/s
0.03 hours (about 2 minutes)
30 GB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
SMS is not recommended.
5 Mbit/s
19.04 hours
10 Mbit/s
9.52 hours
100 Mbit/s
0.95 hours (about 57 minutes)
500 Mbit/s
0.19 hours (about 11 minutes)
1,000 Mbit/s
0.10 hours (about 6 minutes)
50 GB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
SMS is not recommended.
5 Mbit/s
SMS is not recommended.
10 Mbit/s
15.87 hours
100 Mbit/s
1.59 hours
500 Mbit/s
0.32 hours (about 19 minutes)
1,000 Mbit/s
0.16 hours (about 10 minutes)
100 GB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
5 Mbit/s
10 Mbit/s
100 Mbit/s
3.17 hours
500 Mbit/s
0.63 hours (about 38 minutes)
1,000 Mbit/s
0.32 hours (about 19 minutes)
500 GB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
5 Mbit/s
10 Mbit/s
100 Mbit/s
15.87 hours
500 Mbit/s
3.17 hours
1,000 Mbit/s
1.59 hours
1 TB
0.5 Mbit/s
SMS is not recommended.
1 Mbit/s
5 Mbit/s
10 Mbit/s
100 Mbit/s
500 Mbit/s
6.50 hours
1,000 Mbit/s
3.25 hours
Greater than 1 TB
-
SMS is not recommended.
- Evaluation during migration (remaining time)
T = C × 1000 × 8 × (0.8 – P)/0.6/S/3600
- T: the time required, in hours
- C: the total data volume of the source server
- P: the transmission progress. P can be checked on the SMS console. If P is larger than 0.8, the data transmission is complete and you do not need to evaluate the remaining time.
- S: the migration speed in Mbit/s. S cannot be tested accurately with iPerf. To obtain the accurate migration speed:
- Linux: You are advised to use the sar tool or use /proc/net/dev to monitor the NIC speed.
Take an example where there is 100 GB to be migrated (C), the progress (P) is 0.7, and the migration speed (S) is 100 Mbit/s. If we plug in the numbers in our formula, we get:
Migration time T = 100 (GB) × 1,000 × 8 × (0.8 – 0.7)/0.6/100 (Mbit/s)/3,600 = 0.37 hours