Red Hat

1 TB of data needs to read through 4 I/O channesl, each channels supports - 100 MB/s, What is average time taken to read the data ?

Please give the formula for my understanding

The correct answer to this requires more information. The answer to your question as posed:

1. 100 Mb x 4 = 400 Mb/sec or 50MB/sec There are 8 bits per byte 400M/8 =50M
2 There are 20 x 50MB in one GB, 1000 GB in one TB.
3. 1000 x 20 = 20000 seconds or about ~5.5 hours.

The reason this is not all that useful:
1. transmission protocols over slower lines can use compression, example ssh2 using compression: Depending on the data you might get 70% compression. Or 10%.

2. There is overhead for protocol packets, ex: MTU size affects the percentage of data per packet assuming TCP/IP, larger packets are more efficient. Not all hardware can deal with large packets.

3. controllers generally will not let you completely saturate a given line, as kind of a bandwidth limit. Especially if:

4. other processes compete for the same line transmission resource.

5 if you eat the transmission line for 5.5 solid hours the political feedback may not
help your career path where you are. You may want to use just 3 of the 4 transmission lines, so other work can continue.

Your best answer is to time the transmission with a smaller data chunk (example 5% of the size) and multiply that result times 20.

Nice reply...

There is a number 6...

6) What happens if or when there is a connection failure of some sort or major corruption?
Your time calculation(s) will then be of no use to you at all under those conditions...