Results 1 to 3 of 3
  1. #1

    Disabling CPU cores without disabling HT

    We've got a situation we're trying to help someone out on, it's a little bit odd.

    They've got a server with dual octacore CPUs in it, with HyperThreading.

    It's a Linux based system, I think the the purpose of this thread it's not too important which distribution they're on. It uses a Grub bootloader.

    The OS is presented with 16 cores, and 32 threads by the hardware. They're trying to reduce the number of cores presented to the OS, e.g. 8 cores and 16 threads.

    The common answer for this is to put "maxcpus=16" in the grub config file. However, this has the effect of disabling HT first, so you get 16 cores and 16 threads. They want to disable physical cores but keep HT on.

    Anyone know how to do this?
    █ Just Colo Ltd (Company Registration No. 08697471)
    █ Individual colocation: 1U, 2U, and more packages
    █ Based in Reading Tier 4 aligned data centre, gigabit port standard
    www.justcolo.com

  2. #2
    Join Date
    Feb 2013
    Location
    New York
    Posts
    59
    sudo sh -c "echo 0 > /sys/devices/system/cpu#/online"

    This will disable the cpu #'s

    sudo sh -c "echo 1 > /sys/devices/system/cpu#/online"

    This will enable the cpu #'s

    You can make a script to do this for you on every boot up.
    Fast Affordable Professional Virtual Private Servers
    No situation is too much of a handful for us. Let us give you a helping hand with this: FAPVPS Special Offers

  3. #3
    Thanks, that was a suggestion to them, but this isn't recognised by Xen. Should have mentioned that originally, sorry! Xen only picks up disabled cores if they're disabled on boot via Grub as far as I can see from Google.
    █ Just Colo Ltd (Company Registration No. 08697471)
    █ Individual colocation: 1U, 2U, and more packages
    █ Based in Reading Tier 4 aligned data centre, gigabit port standard
    www.justcolo.com

Similar Threads

  1. WHMCS, disabling invoice emails/disabling UNPAID invoice emails
    By kpedana in forum Ecommerce Hosting & Discussion
    Replies: 2
    Last Post: 04-16-2013, 09:54 PM
  2. Is there anyway of disabling the use of other DNS
    By respite in forum Hosting Security and Technology
    Replies: 4
    Last Post: 04-24-2009, 03:52 AM
  3. Disabling SSH
    By Sherby in forum Hosting Security and Technology
    Replies: 2
    Last Post: 02-16-2005, 02:09 PM
  4. Disabling FTP
    By quiddity in forum Dedicated Server
    Replies: 4
    Last Post: 02-11-2005, 01:18 PM
  5. Disabling Majorodomo
    By eddy2099 in forum Dedicated Server
    Replies: 0
    Last Post: 11-29-2002, 05:20 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •