Parallels H-Sphere Documentation System Administrator Guide

 

VPS Limits

(updated for H-Sphere 2.5)
 
 

Related Docs:   VPS Installation FreeVPS Docs

Last modified: 02 Aug 2007

 

WARNING: This documentation covers Parallels H-Sphere versions up to 3.1. For the latest up-to-date Parallels H-Sphere documentation, please proceed to the official Parallels site.

Starting with version 2.5, H-Sphere enables to configure new VPS resource limits in H-Sphere VPS plans and in user control panel.

  

Limit Label * Description Requirements & Restrictions Related VPS Scripts
Disk Limit DLIMIT Disk Limit is the maximum disk usage for a VPS server. Default - disabled (set to 0). Disk Limit cannot be exceeded. No more data will be dumped into the disk if disk usage reaches Disk Limit.
Minimal VPS installation requires ~ 500MB allocated disk space.
vps-dlimit-set <vps_name> <limit> - sets the limit to <limit> Mb for vps <vps_name>

vps-dlimit-get <vps_name> - returns current value for vps <vps_name>
Memory Limit MLIMIT Memory Limit is the maximum total memory usage for processes running and libraries loaded on a VPS server. Default - disabled (set to 0). Memory Limit depends on tasks running on a VPS server.
Memory Limit cannot be exceeded. No more memory will be allocated if VPS total memory usage reaches Memory Limit.
VPS server total memory usage = resident/virtual memory usage + system SWAP·
Minimal VPS installation requires ~15-20Mb allocated memory.
Processes are processed by linux OOM - out of memory killer.
vps-mlimit-set <vps_name> <limit> - sets the limit to <limit> Mb for vps <vps_name>

vps-mlimit-get - returns current value for vps <vps_name>
Process Limit PLIMIT Process Limit is the maximum number of processes running inside a VPS server. Default - disabled (set to 0). Process Limit cannot be exceeded. No new processes will be created if the number of running processes reaches Process Limit. All new processes will be killed.
Minimal VPS installation requires ~10-20 processes to run.
vps-proclimit-set <vps_name> <limit> - sets the limit to <limit> value for vps <vps_name>

vps-proclimit-get <vps_name> - returns current value for vps <vps_name>
Context RSS Limit (HS 2.5+, HS VPS 1.3+) RSSLIMIT Context RSS Limit is maximum resident/virtual memory usage for processes running and libraries loaded on a VPS server. Default - disabled (set to 0). Context RSS Limit depends on virtual memory available on the host server (physical machine), on tasks running on a VPS, and on total memory limit.
Context RSS Limit cannot exceed Memory Limits When VPS virtual memory usage exceeds RSS limit, VPS starts to use the host server's SWAP.
Recommended value for Context RSS Limit = 1/3 * Memory Limit.
vps-rsslimit-set <vps_name> <limit> - sets the limit to <limit> Mb for vps <vps_name>

vps-rsslimit-get <vps_name> - returns current value for vps <vps_name>
File Limit (HS 2.5+, HS VPS 1.3+) FILELIMIT File Limit is the maximum number of file handlers opened inside a VPS server. Default - disabled (set to 0). File Limit cannot be exceeded. No new files will be opened if the number of opened file handlers reaches File Limit. Minimal VPS installation requires ~150-200 opened file handlers allowed. vps-flimit-set <vps_name> <limit> - sets the limit to <limit> value for vps <vps_name>

vps-flimit-get <vps_name> - returns current value for vps <vps_name>
TCP Socket Limit (HS 2.5+, HS VPS 1.3+) TCPLIMIT TCP Socket Limit is the maximum number of TPC connections established on a VPS server. Default - disabled (set to 0). TCP Socket Limit cannot be exceeded. No new connection via TCP (for example, SSH connections) will be established if their number reaches TCP Sockets Limit. vps-tcplimit-set <vps_name> <limit> - sets the limit to <limit> value for vps <vps_name>

vps-tcplimit-get <vps_name> - returns current value for vps <vps_name>
CPU Hard Limit (HS 2.5+, HS VPS 1.4.x+) HARDCPU CPU Hard Limit is the maximum CPU usage (of all host server CPUs) for a VPS server. Default - disabled (set to 0). CPU Hard Limit must be less than 100%.
CPU Hard Limit cannot be exceeded. When usage reaches CPU Hard Limit, new task will be waiting for free CPU resources. That increases system load. CPU Hard Limit depends on VPS task priority.
vps-hcpulimit-set <vps_name> <limit> - sets the limit to <limit> value for vps <vps_name>

vps-hcpulimit-get <vps_name> - returns current value for vps <vps_name>
CPU Guaranteed Limit (CPU Soft Limit) (HS 2.5+, HS VPS 1.4.x+) SOFTCPU The guaranted value of CPU resources (in %) which can be allocated by virtual server if they are required and available in host system. Default - disabled (set to 0). CPU Guaranteed Limit must be less than CPU Hard Limit and 100%. For all registered vps on host Summary CPU Guaranteed Limit values must be less than 100%. vps-scpulimit-set <vps_name> <limit> - sets the limit to <limit> value for vps <vps_name>

vps-scpulimit-get <vps_name> - returns current value for vps <vps_name>

Note: VPS limit labels are set by the vps-get-config.pl script. See VPS Scripts.

 

Hints On Handling VPS Limits

  • Limit values depend on the number of VPSs running on the host, and tasks running on them;
  • When summary virtual memory size used by VPS/context exceedes Memory Limit value, processes can't allocate the required memory and fail to run;
  • If Memory Limit you set to VPS equals the whole virtual memory available on the host, in a while virtual server will use up all the host's swap;
  • If you turn off both Memory and Context RSS limits, kernel can DoS or panic;
  • While setting initial Disk Limit before VPS creation, please mind that it must be greater than minimal Linux RedHat installation size (~450-500Mb). Otherwise, Disk Limit will be turned off during the installation.
  • For lowlevel virtual server limits management use vserver_limit tool provided by FreeVPS. For more info about it run:
    # man vserver_limit

Related Docs:   VPS Installation FreeVPS Docs



© Copyright 2017. Parallels Holdings. All rights reserved.