Questions tagged [iowait]
72 questions
0
votes
1 answer
High IOWait executing JBoss 3.2.7
Server Details:
Kernel: Linux wiq31 2.4.21-9.ELsmp #1 SMP Thu Jan 8 17:08:56 EST 2004 i686 i686 i386 GNU/Linux
CPU: 4 x Intel(R) Xeon(TM) CPU 3.06GHz
Memory: 1028520 kB
JBoss version: 3.2.7
Every time i try to start JBoss, in all CPU's, the iowait…
user64205
- 101
0
votes
3 answers
100% iowait + drive faults in dmesg
I have a server on which resides a fairly visited web app.
It has a raid1 of 2 HDDs, 64MB Buffer, 7200 RPM.
Today it started throwing out errors like:
kernel: ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
kernel: ata2.00: cmd…
w00t
- 1,164
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- 35
0
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1 answer
High I/O wait and Context Switches - how to debug
Update:
sar -W -B -d output added to bottom of post.
I have simulated this on boot. I have uwsgi starting 9 instances of a django app, along with gunicorn for websockets, and dramatiq for queue handing. It seems like it swaps like crazy for the…
Tim Nelson
- 123
- 4
0
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0 answers
High iowait on Ubuntu - having issues
I have a server with Ubuntu 20.04 that ran without problems for a while. However, since a week ago, problems started to arise as everything became slow. On the server I run Virtualizor with a number of VM (VPS) servers.
It looks like everything is…
Legal
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- 1
0
votes
1 answer
High iowait causing problems
Since a week I've been suffering from a server with VPS servers that is very slow and has a lot of IOWAIT. Can someone explain or tell what is causing this problems?
Command: iotop -aoP
PID PRIO USER DISK READ DISK WRITE SWAPIN IO> …
Legal
- 1
- 1
0
votes
2 answers
High iowait, swap nearly always fully in use
I'm often experiencing slowness on a large server that is used by several users simultaneously, with many CPUs (72) and a decent amount of ram (125gb).
Granted, the server runs a lot of stuff so gets a high load, but it pretty much never happens…
dreamer
- 101
- 2
0
votes
0 answers
100% CPU usage from iowait caused by Nginx, not solved by turning sendfile on and directio off
I run a webservice that performs some basic image processing operations.
The webserver first accepts image uploads from users and temporarily stores them. A backend server then downloads the image through a HTTP get request and performs the actual…
ackbar03
- 1
- 1
0
votes
0 answers
Finding source of high IOWait
I have a 5 node elasticsearch cluster. One host has had consistently high IOWait% (40+) for several weeks. The others seem fine (<10%).
Notable:
Host in question is not the cluster master
New indexes are randomly distributed among all 5 hosts
IOTop…
ethrbunny
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0
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2 answers
High iowait with RAID0. CPU 100%. Static data is not cached in RAM
I ask for your help.
I myself can no longer see the way out.
I have a server
1x Xeon E-2236
32RAM
4 x 10TB disks (WDC WD101KRYZ-01) - collected in RAID-0.
The disks are fast. Each individually provides 250MB/s read/write. The RAID-0 array produces…
0
votes
0 answers
75% CPU wait and apt upgrade hanging
Recently I observed a relatively constant 7/8 (core) load on one of my servers. Looking with top, seems that CPU is constantly 75% waiting:
Tasks: 401 total, 1 running, 400 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 0.0 sy, 0.0 ni, 25.0…
jazzman
- 51
- 4
-1
votes
1 answer
What exactly is IOWait
I know that the IOWait metric is the amount of time that a cpu is waiting for IO.
As I understand it IOWait always refers to disc io. But why is that? Why doesn't network IO, presumably involving bus communication on the local system and IO for the…
user307927
- 133
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- 4
-2
votes
1 answer
High IO wait when test disk with dd
My server is using two SATA disk Raid 1. I test disk using dd
#!/bin/bash
i=0
MAX_LOOP=10
while [ $i -lt $MAX_LOOP ]
do
dd if=/dev/zero of=/data/output bs=1G count=10
((i++))
done
The write speed is very good about 310MB/s. But IO…
Luke Nguyen
- 111
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- 7