uptime command is used to view the server running how long and how many users log in, the server's load quickly informed.
uptime output content comprising a load average, 5, 15 minutes shows the most recent load conditions. The number of processes waiting for the CPU processing on behalf of its value, if the CPU does not have time to deal with these processes, load average value will rise; otherwise it will be reduced. Best value load average is 1, indicating that each process can be handled immediately and no CPU cycles are lost. Single-CPU machine, or a value of 2 is acceptable; For multiple CPU machine, load average value may be between 8-10. Uptime command may be used to determine network performance. For example, a network application performance is very low, to see if the server load by running the uptime is high, if not, then the problem should be caused by networking.
The following is a running instance uptime of:
9:24am up 19:06, 1 user, load average: 0.00, 0.00, 0.00
You can also view / proc / loadavg and / proc / uptime two documents, be careful not to edit files in / proc, use cat commands to view, such as:
liyawei: ~ # cat / proc / loadavg
0.0 0.00 0.00 1/55 5505
uptime command usage is very simple: direct input
# uptime
Example:
18:02:41 up 41 days, 23:42, 1 user, load average: 0.00, 0.00, 0.00
1 can be considered optimal load value. Depending upon the system load will change, too. Single CPU system SMP systems 1-3 and 6-10 are possible acceptable.
There is also a parameter -V, is used to query version. (Note the capital letter v)
[linux @ localhost]$ uptime -V
procps version 3.2.7
[linux @ localhost]$ uptime
Showing results:
10:19:04 up 257 days, 18:56, 12 users, load average: 2.10, 2.10,2.09
Contents Description:
10:19:04 // current time
up 257 days, 18:56 // host has been in operation, the greater the time, the more stable your machine.
12 user // user connections, the total number of connections rather than the number of users
System load average // average load, average load most recent statistical system 5, 15 minutes
So what is the average load system? Load average is the average number of processes in the run queue specific time interval. If each currently active CPU core number, then the process is not greater than 3, then the performance of the system is good. If the number of tasks for each CPU core is greater than 5, then the performance of this machine have serious problems. If your host is one pair of linux-core CPU, so that when Load Average of 6 when indicating the machine has been fully used.