Linuxdd read/write speed

Article Title: linuxdd read and write speed to disk. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

Time is used for timing. dd is used for copying, reading from if, and writing to. If =/dev/zero does not produce IO, so it can be used to test the pure write speed. Similarly, of =/dev/null does not generate IO and can be used to test the pure read speed. Bs is read or written each time.

The size of a block. count indicates the number of read/write blocks.

Specify the speed at which the file is written to the hard disk.

1. Test/directory disk's pure write speed:

[Root @ base-dmz1/] # time dd if =/dev/zero bs = 1024 count = 1000000 of =/1Gb. file

1000000 + 0 records in

1000000 + 0 records out

1024000000 bytes (1.0 GB) copied, 2.57314 seconds, 398 MB/s

Real 0m2. 787 s

User 0m0. 920 s

Sys 0m1. 867 s

The above is displayed only when time is used. It is not required in linux5. It is not included in linux4 (1024000000 bytes (1.0 GB) copied, 2.57314 seconds, 398 MB/s, therefore, the time command is required.

The copy time.

2. Test/directory disk's pure read speed:

Dd if =/kvm/ftp/other/1Gb. file bs = 64 k | dd of =/dev/null

382860 + 0 records in

382860 + 0 records out

3136389120 bytes (3.1 GB) copied, 68.38 seconds, 45.9 MB/s

Real 1m8. 406 s

User 0m0. 039 s

Sys 0m4. 573 s

3. Test the read/write speed (what is this ):

Dd if =/vat/test of =/oradata/test1 bs = 64 k

Dd: writing '/oradata/test1': No space left on device

5025 + 0 records in

5024 + 0 records out

329261056 bytes (329 MB) copied, 23.8813 seconds, 13.8 MB/s

Note: In theory, the larger the replication volume, the more accurate the test.