flushcaches

Flushcaches is a command-line utility commonly found in Unix-like operating systems. Its primary function is to clear the operating system's disk cache. The disk cache is a part of system memory that the operating system uses to store frequently accessed data from the hard drive. This caching mechanism speeds up subsequent reads of the same data by avoiding the need to access the slower disk.

However, there are situations where clearing this cache is beneficial or necessary. For instance, developers might use flushcaches during software testing to ensure that they are measuring actual disk I/O performance rather than cached read times. System administrators might employ it after certain system maintenance tasks or when troubleshooting disk I/O related issues to rule out cache-related problems.

When flushcaches is executed, it instructs the operating system to discard the contents of its disk cache. This means that any data previously held in memory for faster access will be removed. Consequently, the next time that data is requested, the system will have to retrieve it directly from the storage device, which can temporarily slow down performance. The utility typically requires elevated privileges, such as root access, to operate. Its use should be considered carefully, as it can impact system responsiveness until the cache is repopulated with frequently used data.