In hard disk, the read and write operations are managed by Disk I/O. The speed of the server in reading and writing information to disk straight away affect one’s server performance and the performance of cPanel and WHM. The load of one’s server increases if the system struggles with high disk I/O wait time.
There are nearly seven problems that attack the high disk I/O. They are:
Where the average system load exceeds 1.
Where one get notifications about an offline service or it is conveyed that the system cannot restart a service.
Whereby the hosted websites may take more than a minute to load.
Due to which the Exim service performs comparatively slowly or does not respond.
Hampering the POP or IMAP services, where they perform comparatively slowly or do not respond.
Where it performs slowly or do not respond as it should (for example: Roundcube, Horde, or SquirrelMail).
Which results in the slow performance of the WHM or cPanel interfaces when one adds email accounts, databases, or other items.
If there are problems, surely there are solutions even. We can combat the problems with certain valuable recommendations. It will be easier if we discuss the problems and the recommendations side by side.
One needs to use the top command to find the average wait time on one’s server. The %wa statistic at the top of the output will indicate one’s server’s average disk wait.
The CPU cores must wait to process data on hard disk if the I/O wait percentage is greater than one divided by the number of your CPU cores. As for example, if the system possesses four CPU cores and the server %wa statistic is 8.0, then the actual %wa is 2.0. Because of the actual %wa larger than 1.0, the CPU cores must wait before they can process data on hard disk.
Then one can use the sar command to determine the history of the server’s disk I/O wait.
The sar command provides the history of the server’s load averages. Using this command, one can determine how many times the server experienced high disk I/O.
Technical problems can arise at any point. If we manage to find a technical solution to it, then it won’t be a big issue.