Results 1 to 9 of 9
  1. #1
    Join Date
    Jan 2011
    Posts
    671

    Question High Load but low cpu and iowait - cPanel/WHM

    My server currently has high load than normal, the top command doesnt reveal anything unusual (high cpu idle), and the iowait is hovering around 2% constantly.

    I've tried running 'iotop' which shows the following process using most of the IO:

    jbd2/sda1-8
    What is this process and how can I reduce my server load?

  2. #2
    Quote Originally Posted by kshazad86 View Post
    My server currently has high load than normal, the top command doesnt reveal anything unusual (high cpu idle), and the iowait is hovering around 2% constantly.

    I've tried running 'iotop' which shows the following process using most of the IO:



    What is this process and how can I reduce my server load?

    JBD stand for 'journaling block device' (more information about it find here) which its job is in between the block device and the file system.

    so it is related to your ext4 file system using I/O and causing high loads. check if there's something running on your server or if there isn't anything active check the log files and see if they're populated with some interesting messages.

    anyhow, when you say 'has high load than normal' what exactly the load is/was?

    could you post the output of `top -n1 -b` when the load will be high

    to reduce your server load, you first need to track-down the cause which is causing high loads and then optimize/fix it.
    ---=== RoseHosting.com Admin ===---
    Linux Cloud Hosting - linuxcloudvps.com
    Linux VPS Hosting - rosehosting.com
    High Quality Linux virtual servers with lots of Guaranteed RAM and HDD space, Impeccable Service.

  3. #3
    Join Date
    Jan 2011
    Posts
    671
    You've basically copied and pasted this from a different website which I already checked before posting on this board.

    There are no issues with the log files.

  4. #4
    Join Date
    Nov 2009
    Location
    /etc/my.cnf
    Posts
    9,761
    You may have an defective drive, Have you had them checked over?
    LeapHost High Performance Fully Managed App Solutions Powered By NitroStackô
    Fast Dedicated Servers | 15+ Global Locations | Server Management Specialists

  5. #5
    Ok, then please provide some output for everyone reading this thread to be able to help you with your issue.

    Regarding the ext4 io interrupts, you may look if some application is invoking such activities when your server's load is high or idling and thus looking in the log files for any unusual activities.

    try using `ps auwwwxf`, `top -n1 -b`, `iotop` etc.. to find what exactly is happening.

    as for the JBD, I read some time ago about it and as you asked 'What is this process' I remembered about it and referenced you there.

    it would be nice if you post some more information so anybody can have a deeper look into your problem.

    thanks,
    ---=== RoseHosting.com Admin ===---
    Linux Cloud Hosting - linuxcloudvps.com
    Linux VPS Hosting - rosehosting.com
    High Quality Linux virtual servers with lots of Guaranteed RAM and HDD space, Impeccable Service.

  6. #6
    Join Date
    Jan 2011
    Posts
    671
    Server load resolved itself, consulted with cPanel and was told the load was not abnormal (2.0 on 8 Core CPU).

  7. #7
    Quote Originally Posted by kshazad86 View Post
    Server load resolved itself, consulted with cPanel and was told the load was not abnormal (2.0 on 8 Core CPU).
    I agree with that too. that's definitely not a high load for your 8 core cpu.
    ---=== RoseHosting.com Admin ===---
    Linux Cloud Hosting - linuxcloudvps.com
    Linux VPS Hosting - rosehosting.com
    High Quality Linux virtual servers with lots of Guaranteed RAM and HDD space, Impeccable Service.

  8. #8
    Join Date
    Jun 2012
    Location
    Melbourne, Australia
    Posts
    306
    Is it a dedicated server or are you sharing with other users? Sometimes another node can impact your performance.

  9. #9
    Join Date
    Mar 2003
    Location
    Jaipur, India
    Posts
    632
    Hi,

    I think there is a unnecessary server load on your server, or someone trying to install TCP bombs in your network, you should find our the particular IP's from :-

    netstat -an | grep :80 | sort
    This will show only active Internet connections to the server on port 80 and sort the results. Useful in detecting a single flood by allowing you to recognize many connections coming from one IP.

    netstat -n -p|grep SYN_REC | wc -l
    Run this command to find out how many active SYNC_REC are occurring on the server. The number should be pretty low, preferably less than 5. On DoS attack incidents or mail bombs, the number can jump to pretty high.

    Find out those IP's which you find making high concurrent connections, try to stop them in your /etc/hosts.deny file, or in your firewall, CSF would be best option.
    ZNetLive
    Web Hosting for Designers & Developers

  10. Newsletters

    Subscribe Now & Get The WHT Quick Start Guide!

Similar Threads

  1. CPU load and iowait - Is this normal?
    By dmmcintyre3 in forum VPS Hosting
    Replies: 2
    Last Post: 11-30-2010, 12:57 AM
  2. [Help ] CPU load - 90% IOwait
    By constantine in forum Hosting Security and Technology
    Replies: 7
    Last Post: 09-10-2008, 02:16 PM
  3. load is low CPU usage is high?
    By quinn_TE in forum Hosting Security and Technology
    Replies: 6
    Last Post: 07-26-2007, 05:32 PM
  4. Low cpu, low ram, but high load
    By syang3 in forum Hosting Security and Technology
    Replies: 3
    Last Post: 09-20-2004, 10:35 AM
  5. what causes system load to be high when CPU use is low?
    By disgust in forum Dedicated Server
    Replies: 11
    Last Post: 09-12-2004, 07:45 PM

Related Posts from theWHIR.com

Posting Permissions

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