Questions tagged [iowait]
72 questions
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One process takes all server resources (iowait?)
I have multiple processes running simultaneously on the same box under CentOS 7 (each one on behalf of the separate Linux user).
I use Zabbix for monitoring.
Sometimes the following pattern appears on CPU utilization graph.
If you zoom in, then…
zavg
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What is a "normal" latency/performance of inserts on mariadb or mysql?
Hadn't used MySQL family for years. Now need to move from OracleDB to either MariaDB or PostgreSQL.
So on a similar "hardware" (Openstack VM: RHEL 7.3, 4HT cores of 2.5GHz Xeon E312xx, "local" SAN & SATA storage) got Oracle11g and MariaDB10.3…
Vlad
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Issues with sudden high iowait on RabbitMQ Cluster
we run a RabbitMQ Cluster with 6 c5.2xlarge nodes on AWS. The Version is 3.6.14 on Erlang 19.1. They run in docker containers and mount a local volume to /var/lib/rabbitmq/mnesia.
The docker run command is as follows:
docker run -d \
--name…
paraa
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4 answers
Resolving high iowait on Samba server
We've got a centralised file cache which a cluster of web servers use to store "heavyweight" pages. Each webserver uses Samba to mount this shared area.
We're getting a lot of iowait on the server, and I wondered what steps we could take to make a…
Paul Dixon
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qemu-kvm VM hangs at iowait with virtio drive
We are seeing instances of a VM hanging with the following symptoms:
load average 800, processes stuck, CPU 100% in iowait
reading files work, writing files hang the system
RAM utilization is high, but that is expected when the system is working…
nicolasochem
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3 answers
MySQL and high jdb2 io/wait
I am running MySQL 5.5 with InnoDB tables. There are about 200 queries per second. There are also tables with 500 000 or more rows. But I have big issues with server load and io/wait especially with the jdb2.
jdb2/md2-8 is taking 99% IO/wait see…
Welite
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Monitoring/Warning for IOWait
I had a downtime today on my server because of a high IOWait. I could not do mostly anything on the server, I managed only to run top to see the IOWait, but I did not have iotop installed at that time, so I couldn't see which process is causing it.…
Vojtěch
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High Iowait + High load average on a monitoring server
I've a nagios server which was perfectly working up to a few days ago. I've stopped it and restarted it to increase its RAM, and since then, iowait increased dramatically on the server (more than 20%, it was less than 1% before). I've tried to put…
Golgot
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2 answers
CentOS 5 extremely slow when is running a download
When my server is downloading a file or executing other IO operations the other server functions become extremely slow (almost locked). Even other functions that do not use the network. When a download is in progress, if I start typing in…
Tomir Schmite Jr.
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high linux server load
I have a problem with high server load (load average from 10 to 100+) when there is a lot of web traffic. There are also noticable delays when reading/writing files.
Machine is a Apache web server. Web page is using PHP and is accessing/opening some…
gib
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1 answer
Why does md resync cause no iowait?
I've known the defintion of %iowait as
Time the CPU spent idling/blocking, because it had to wait on an IO operation to complete.
Now take a simple Linux system with an mdraid1 and two disks.
/proc/mdstat shows that the resync is running at about…
dog
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1 answer
What happened to hard disk
I suspect that with my hard drives is something wrong.
iostat -d -x -m
root@srv2:~# iostat -d -x -m
Linux 2.6.32-5-amd64 (srv2.host.com) 04/23/13 _x86_64_ (2 CPU)
Device: rrqm/s wrqm/s r/s w/s rMB/s …
Lari13
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Copying cause big iowait
I have dedicated server with 3 HDD. System disk, backup disk (same as system disk) and data disk. When I copy lot of data with cp (say, between backup disk and data disk) load average goes sky high.
For instance, the load average at the moment is…
Vald
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How to manage iowait over cifs?
For backup purposes we have Cifs file Server running that contains encrypted containers for backing up the more sensitive data. The container is mounted with cryptsetup and loop as a local filesystem and the rsync is used for backups.
Because the…
Silvia
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Why does nginx 1.0.0 appear to not use the kernels open file cache on Gentoo? (high iowait)
free -m
total used free shared buffers cached
Mem: 7996 2043 5952 0 73 140
-/+ buffers/cache: 1830 6165
Swap: 7812 15 7797
nginx…
Daniel
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