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Questions tagged [tuning]

The tag has no usage guidance.

5
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3answers
1k views

How to change the length of time-slices used by the Linux CPU scheduler?

Is it possible to increase the length of time-slices, which the Linux CPU scheduler allows a process to run for? How could I do this? Background knowledge This question asks how to reduce how ...
1
vote
0answers
52 views

is there any way to increase spawn rate of MinSpareServers in apache prefork

My server faces huge traffic only for short duration every day. And I don't want to waste my resource by running high amount of MaxSpareServers throughout the day. So, I would like to know is there ...
1
vote
1answer
539 views

CentOS 7 - When THP is disabled is it safe to ignore defrag setting?

I need to disable THP (Transparent Huge Pages). Many tutorials on the web advise to set never (0 for last one) value for below options. /sys/kernel/mm/transparent_hugepage/enabled /sys/kernel/mm/...
1
vote
1answer
238 views

slow/frozen ext4 // task sync blocked on big mostly write only server

We have several 90TB servers (Areca RAID-6 partitioned into 10 ext4 partitions) The application is basically a ring buffer; continuously writing data and deleting old data. As such, each partition is ...
1
vote
1answer
688 views

How can I create my own custom progress bar in Conky?

I have started using Conky some days ago, and I'm willing to create my own configuration. I have added some colors, cool ASCII art and learned the basics. However, I don't like the default progress ...
4
votes
0answers
188 views

systemd slices even with low CPUShare heavily affect system responsiveness

I've created custom slice (so now I have 4 slices user, system, machine, important) and assigned huge number to CPUShares. System felt really unresponsive under high load in this slice, what seems to ...
1
vote
1answer
212 views

Fast filesystem for virtual backup environments

I know filesystem supporters war is behind the corner and there are plenty of fine tuning guide for each filesystem in the wild, so please stick to the specifications: I'm asking what would you ...
3
votes
1answer
2k views

Does dm-multipath schedule I/O?

I have a multipath device I'm interested in: [root@xxx dm-7]# multipath -ll mpathf mpathf (3600601609f013300227e5b5b3790e411) dm-7 DGC,VRAID size=3.0T features='1 queue_if_no_path' hwhandler='1 alua' ...
-1
votes
1answer
736 views

Make TCP to reconnect automatically and quickly

In my Debian Linux system apt-get dist-upgrade is sometimes stalled with [Waiting for headers] message. To make it pass faster I press Ctrl+C and start the command again. How to tune the system to ...
3
votes
0answers
2k views

Tuning NFS: Identifying source of getattr requests

we run some Linux NFS clients against a NetApp NFS storage system. Currently we have over 50% getattr requests running against the NetApp using up precious CPU cycles. Using the netapp-top.pl script ...
2
votes
1answer
728 views

Memory Usage in Linux [duplicate]

How to setup limit for process to memory usage? Similar to open files limit in /etc/security/limits.conf: ubuntu soft nofile 4096 ubuntu hard nofile 8192 ...
1
vote
1answer
2k views

Is it possible to stop specific BIND Log messages from being logged?

I have setup a BIND DNS server and a munin monitoring system which is configured to monitor BIND as well. The OS is Ubuntu Server 12.04.4 and the BIND version coming with it is 9.8.1-P1. Munin runs ...
0
votes
0answers
38 views

If a buggy application underperforms, it it possible server tuning could have no affect?

To set the stage, imagine if you will: A read-heavy Tomcat Application with MySQL on Red Hat Enterprise Linux with some problematic Java Class files which resulted in the application performing a ...
4
votes
1answer
1k views

CentOS 5 - hdparm - how to set DMA mode

I'm running CentOS 5 with a PATA hard drive. I've used hdparm to tune the hard disk for better performance, but there are 2 settings that don't work: hdparm -M 254 /dev/hda gives the error ...
1
vote
2answers
3k views

error: “net.inet.ip.fastforwarding” is an unknown key

I've been doing some research into improving performance for OpenVPN and I found out about setting fastforwarding to 1 but when I tried I got the error error: "net.inet.ip.fastforwarding" is an ...