Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
The TL;DR is unless you're running CentOS 7 on a laptop or as a virtual guest, you should probably run 'tuned-adm profile throughput-performance'
I wrote up the full details here -> http://jperrin.org/centos/boosting-centos-server-performance/
On Thu, Sep 21, 2017 at 11:45:12AM -0700, Jim Perrin wrote:
Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
The TL;DR is unless you're running CentOS 7 on a laptop or as a virtual guest, you should probably run 'tuned-adm profile throughput-performance'
I wrote up the full details here -> http://jperrin.org/centos/boosting-centos-server-performance/
Cool. thanks!
I have noticed (without being quite sure what to do about it) that my Centos 7 desktop (six core AMD Vishera) seems sluggish at times, when there doesn't seem to be much running that should be a system hog. I'll see if this change helps resolve that.
Does running the command shown there make a permanent change, i.e., one that survives reboot?
On 09/21/2017 07:02 PM, Fred Smith wrote:
On Thu, Sep 21, 2017 at 11:45:12AM -0700, Jim Perrin wrote:
Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
The TL;DR is unless you're running CentOS 7 on a laptop or as a virtual guest, you should probably run 'tuned-adm profile throughput-performance'
I wrote up the full details here -> http://jperrin.org/centos/boosting-centos-server-performance/
Cool. thanks!
I have noticed (without being quite sure what to do about it) that my Centos 7 desktop (six core AMD Vishera) seems sluggish at times, when there doesn't seem to be much running that should be a system hog. I'll see if this change helps resolve that.
Does running the command shown there make a permanent change, i.e., one that survives reboot?
Yes. This command will drop an 'active-profile' file in /etc/tuned that will be used and survive reboots, kernel updates, etc.
On Fri, 22 Sep 2017 09:04:58 -0700 Jim Perrin wrote:
Yes. This command will drop an 'active-profile' file in /etc/tuned that will be used and survive reboots, kernel updates, etc.
[root@mutt frankcox]# tuned-adm active Current active profile: virtual-guest
???
This is my main desktop computer and it isn't any kind of a virtual system. I do run VirtualBox on it occasionally, though.
What could have happened here?
On Fri, Sep 22, 2017 at 12:05 PM, Frank Cox theatre@sasktel.net wrote:
On Fri, 22 Sep 2017 09:04:58 -0700 Jim Perrin wrote:
Yes. This command will drop an 'active-profile' file in /etc/tuned that will be used and survive reboots, kernel updates, etc.
[root@mutt frankcox]# tuned-adm active Current active profile: virtual-guest
???
This is my main desktop computer and it isn't any kind of a virtual system. I do run VirtualBox on it occasionally, though.
What could have happened here?
Does virt-what give you any output?
On Thursday 21 September 2017, Jim Perrin jperrin@centos.org wrote:
Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
On my CentOS 6 system, tuned wasn't installed by default, but when I installed it and followed your instructions, that did seem to improve some programs' performance considerably.
On 09/22/2017 07:46 PM, Yves Bellefeuille wrote:
On Thursday 21 September 2017, Jim Perrin jperrin@centos.org wrote:
Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
On my CentOS 6 system, tuned wasn't installed by default, but when I installed it and followed your instructions, that did seem to improve some programs' performance considerably.
Glad it helped.
Jim Perrin wrote:
Last week we noticed that the default scheduler isn't being set properly in CentOS 7. I haven't checked this for CentOS 6, but it might be worth exploring.
The TL;DR is unless you're running CentOS 7 on a laptop or as a virtual guest, you should probably run 'tuned-adm profile throughput-performance'
I wrote up the full details here -> http://jperrin.org/centos/boosting-centos-server-performance/
Thank you very much for the notice! Looking at a couple machines, I found that the automatic choice of profile isn´t what I would want.
Now I wonder how everyone deals with this, i. e. do you set a profile once and never change it, or do you keep changing the profile according to circumstances? Is changing it even advisable, i. e. do all the settings applied through a profile always take effect immediately, or may a reboot be required for some of them?
For example, 'virtual-host' is a good choice during the day when the server is being used while 'balanced' --- or even 'powersave' --- could be used at night when the server is idle.
I made entries in the crontab for this to change the profile at the appropriate times. But is that a good idea?
On 09/23/2017 03:52 AM, hw wrote:
Thank you very much for the notice! Looking at a couple machines, I found that the automatic choice of profile isn´t what I would want.
Now I wonder how everyone deals with this, i. e. do you set a profile once and never change it, or do you keep changing the profile according to circumstances? Is changing it even advisable, i. e. do all the settings applied through a profile always take effect immediately, or may a reboot be required for some of them?
The change is immediate, however some processes may need to be restarted.
For example, 'virtual-host' is a good choice during the day when the server is being used while 'balanced' --- or even 'powersave' --- could be used at night when the server is idle.
I made entries in the crontab for this to change the profile at the
appropriate times. But is that a good idea?
Not really. Ultimately this is what the scheduler itself is meant to be doing. What you've described is what the 'balanced' profile actually does.
For server users, I'd say it's a set it and forget it thing.
Laptop users who want performance when plugged in on AC, and powersave when on battery... Those are the people who should be using something like tlp or powertop (both in EPEL I think) to change this automatically.
Jim Perrin jperrin@centos.org writes:
[...] The change is immediate, however some processes may need to be restarted.
For example, 'virtual-host' is a good choice during the day when the server is being used while 'balanced' --- or even 'powersave' --- could be used at night when the server is idle.
I made entries in the crontab for this to change the profile at the
appropriate times. But is that a good idea?
Not really. Ultimately this is what the scheduler itself is meant to be doing. What you've described is what the 'balanced' profile actually does.
For server users, I'd say it's a set it and forget it thing.
Hmm, after looking into it a bit, I think that´s probably the idea. Alas, it doesn´t work that way *unless* the admin does look into it and creates a profile suited to each particluar machine.
Like I´m basically ok with the 'throughput-performance' and 'virtual-host' profiles except for using the performance governor. That only makes sense, if at all, during the day when the servers are being used and no sense at all during the nights when they are idle. So I need to make my own profiles which use the conservative governor.
But: I´m not sufficiently familiar with all the available tuning options to really make good decisions. The 'throughput-performance' profile uses:
[cpu] governor=performance energy_perf_bias=performance min_perf_pct=100
Does it even make sense to just change the governor to conservative, or does that conflict with other settings? I don´t know what the other two mean, and I think it would be stupid to run all CPUs at full throttle all the time. These servers idle a lot and can´t be fast enough when they are supposed to do something.
BTW, what is the dynamic adjustment of tuned supposed to do? Why is tuned enabled as a daemon that does nothing because dynamic tuning is disabled?
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Frank Cox -
Fred Smith -
hw -
hw -
Jim Perrin -
Jon Pruente -
Yves Bellefeuille