nocache - don't use Linux page cache on given command

       If your use case is a  backup processes that should not interfere with the present state of the cache too
       much, consider using cgroups instead. They're much cleaner and carry less overhead than this tool.

       For example, if your system uses systemd, you can do:

       systemd-run--scope--property=MemoryLimit=500M -- backupcommand

       For more info, see the README on https://github.com/Feh/nocache

nocache                                            March 2013                                         NOCACHE(1)

       The `nocache` tool tries to minimize the effect an application has on the Linux file system  cache.  This
       is  done  by  intercepting  the  `open`  and  `close`  system  calls and calling `posix_fadvise` with the
       `POSIX_FADV_DONTNEED` parameter. Because the library remembers which pages (ie., 4K-blocks of  the  file)
       were  already  in  file  system cache when the file was opened, these will not be marked as "don't need",
       because other applications might need that, although they are not actively used (think: hot standby).

       nocache - don't use Linux page cache on given command

-n<n> "Set number of fadvise calls"
              Execute the `posix_fadvise` system call <n> times in a row.  Depending on your machine, this might
              give  better  results  (use  it  if  in  your  tests `nocache` fails to eradicate pages from cache
              properly).

       nocache [-n <n>] command [argument...]