When people talk about sequential vs random writes to a file, they’re generally drawing a distinction between writing without intermediate seeks (“sequential”), vs. a pattern of seek-write-seek-write-seek-write, etc. (“random”). The distinction is very important in traditional disk-based systems, where each disk seek will take around 10ms. Sequentially writing data to that same disk takes about … Read more
Sounds like you want the sync command, or the sync() function. If you want disk cache flushing: echo 3 | sudo tee /proc/sys/vm/drop_caches
TL;DR: You have two options. Use the –smallfiles startup option when starting MongoDB to limit the size of the journal files to 128MB, or turn off journalling using the –nojournal option. Using –nojournal in production is usually a bad idea, and it often makes sense to use different write concerns also in development so you … Read more
External fragmentation Total memory space is enough to satisfy a request or to reside a process in it, but it is not contiguous so it can not be used. Internal fragmentation Memory block assigned to process is bigger. Some portion of memory is left unused as it can not be used by another process.
Use SysInternal’s RAMMap app. The Empty / Empty Standby List menu option will clear the Windows file cache.