NAME

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

SYNOPSIS

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

OPTIONS

       -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).

DESCRIPTION

       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).

       Use case: backup processes that should not interfere with the present state of the cache.