01-19-2019
Note that some systems actively try to use otherwise unused memory to speed up running processes. For example, if a process starts reading from a large file, the system might read the next few blocks (or megabytes) of that file into a system buffer so the data will be in memory without having to wait for the disk to rotate if that process reads the next block.
If other processes start up need the memory that was used for read-ahead buffers they can be reallocated to the next process without affecting how fast the new process can be loaded.
Different versions of BSD, Linux, and UNIX systems use different algorithms to try to make efficient use of memory. And, different releases of each of those systems may change the algorithms as the vendors think they have learned something from past experiences.
In other words, there can be lots of "free" memory may be used to hold data that may soon be useful to someone even though it can be re-allocated immediately if someone asks for it to be put to a specific use.
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LEARN ABOUT CENTOS
new-kernel-pkg
NEW-KERNEL-PKG(8) System Manager's Manual NEW-KERNEL-PKG(8)
NAME
new-kernel-pkg - tool to script kernel installation
SYNOPSIS
new-kernel-pkg [-v] [--mkinitrd] [--rminitrd] [--dracut]
[--initrdfile=initrd-image [--depmod] [--rmmoddep]
[--kernel-args=args] [--remove-args=args]
[--banner=banner] [--multiboot=multiboot]
[--mbargs=mbargs] [--make-default] [--add-dracut-args]
[--add-plymouth-initrd] [--host-only]
<--install | --remove | --update | --rpmposttrans> <kernel-version>
DESCRIPTION
new-kernel-pkg is a tool used in packaging to automate the installation of a new kernel, including the creation of an initial ram filesys-
tem image, updating of bootloader configuration, and other associated tasks.
OPTIONS
-v Be verbose.
--mkinitrd
Create a new initial ram filesystem image.
--rminitrd
Remove an initial ram filesystem image.
--dracut
When creating a new initial ram filesystem image, use dracut(8) rather than mkinitrd(8). Used in conjunction with --mkinitrd .
--initrdfile=initrd-image
Use the specified file as the initial ram filesystem image.
--depmod
Create modules.dep and related files.
--rmmoddep
Remove modules.dep and related files.
--kernel-args=args
Use args as the boot command line for this kernel.
--remove-args=args
Remove specified kernel arguments for this kernel.
--banner=banner
Display banner as the banner text in the bootloader.
--multiboot=multiboot-image
Use multiboot-image as a multiboot image.
--mbargs=mbargs
Use mbargs as arguments to the multiboot image.
--make-default
Make this kernel the default boot option.
--add-dracut-args
Automatically generate dracut options and add them to the kernel command line.
--add-plymouth-initrd
Automatically add plymouth to the initial ram filesystem image.
--host-only
Make an initial ram filesystem image that is specific to the running system.
--install kernel-version
Install a new kernel.
--remove kernel-version
Remove an installed kernel.
--update kernel-version
Update the specified kernel.
--rpmposttrans kernel-version
Run the rpmposttrans for the specified kernel.
SEE ALSO
grubby(8) installkernel(8)
AUTHORS
Erik Troan
Jeremy Katz
Peter Jones
Wed Apr 14 2010 NEW-KERNEL-PKG(8)