Stress Linux system: stress-ng

worthy: stress-ng

NOTE: it's the newer/better version of "stress"

Quote:

stress-ng current contains the following methods to exercise the machine:

• CPU compute - just lots of sqrt() operations on pseudo-random values. One can also specify the % loading of the CPUs
• Cache thrashing, a naive cache read/write exerciser
• Drive stress by writing and removing many temporary files
• Process creation and termination, just lots of fork() + exit() calls
• I/O syncs, just forcing lots of sync() calls
• VM stress via mmap(), memory write and munmap()
• Pipe I/O, large pipe writes and reads that exercise pipe, copying and context switching
• Socket stressing, much like the pipe I/O test but using sockets
• Context switching between a pair of producer and consumer processes

In-memory page states and kscand

1. kscand task
1. periodically sweeps through all the pages in memory
2. notes "last access time"
1. was accessed?
1. increments page's age counter
2. wasn't accessed?
1. decrements page's age counter
3. age counter at zero
1. move page to inactive dirty state

In-memory page states

1. free
1. begin in this state
2. not being used
3. available for allocation, i.e. made active
2. active
1. allocated
2. actively in use
3. inactive dirty
1. has fallen into disuse
2. candidate for removal from main memory
4. inactive laundered
1. interim state
2. contents are being moved to disk
1. when disk I/O operation complete
1. moved to the inactive clean state
2. if, during the disk operation, the page is accessed
1. moved back into the active state
5. inactive clean
1. laundering succeeded, i.e. contents in sync with copy on disk
2. may be 
1. deallocated
2. overwritten

Taken: http://www.redhat.com/magazine/001nov04/features/vm/

Vagrant: how to set vm memory and force gui mode

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant::Config.run do |config|

  config.vm.define :zenoss do |zenoss_config|
      zenoss_config.vm.box  = "quantal64"
      zenoss_config.vm.network :hostonly, "10.66.66.10"
      zenoss_config.vm.forward_port 80, 8885
      zenoss_config.vm.customize ["modifyvm", :id, "--memory", 1024]
  end

  config.vm.define :desktop do |desktop_config|
      desktop_config.vm.box  = "quantal64"
      desktop_config.vm.network :hostonly, "10.66.66.20"
      desktop_config.vm.boot_mode = :gui
  end

end