====== Block IO limits ======

===== Project description =====

The goal of the project is to add the block IO usage accounting to the existing racct/rctl infrastructure. I want to make it possible for the system administrator to limit the block IO throughput for a particular process, user or a jail to for example 1MB per second read access.

===== Deliverables =====
  * block IO throughput limit for write access
  * block IO throughput limit for read access

===== Contact =====
  * [[/RudolfTomori|Rudo Tomori]]
  * [[/EdwardTomaszNapierala|Edward Tomasz Napierała]] - mentor

===== Patches =====
**The following patch is work in progress**
  * %%FreeBSD%%-CURRENT http://www.ms.mff.cuni.cz/~tomor6am/racct-io/racct_io_current_r248247.patch

==== Apply the patch as follows ====

cd /usr/src\\ 
patch -p1 < //patch-file.patch//

==== Required kernel options ====
options RACCT\\ 
options RCTL

==== Usage examples ====

rctl -a user:tom:ior:deny=1M
Adds a 1MB/sec IO limit for user tom for block IO read access.

rctl -a process:1657:iow:deny=1M
Adds a 1MB/sec IO limit for process with id 1657 for block IO write access.

===== Useful links =====
  * [[/Hierarchical_Resource_Limits]]