search for: swappines

...t my first time I see this behaviour to this extent/on so many servers. So you can say that I'm kind of a newbie in swapping ;) > If you don't explicitly lock things into memory, file I/O can and will > cause idle pages to get pushed out. It happens less often if you > manipulate swappines. So, is a swappiness value of 60 not recommended for servers? I worked with hundreds of servers (swappiness 60) on a social platform and swapping very rarely happened and then only on databases (which had swappiness set to 0). The only two differences (that I can see) to my current servers are...

...it's very low. AFAIK it's, as you already suggested, just that some (probably unused) parts are swapped out. But, some of those parts are the salt-minion, php-fpm or mysqld. All services which are important for us and which suffer badly from being swapped out. I already made some tests with swappiness 10 which mildly made it better. But there still was swap usage. So I tend to set swappiness to 1. Which I don't like to do, since those default values aren't there for nothing. Is it possible that this happens because the servers are VMs on an ESX-server. How could that affect this? How c...

.../questions/196725/how-to-mlock-all-pages-of-a-process-tree-from-console (I've always only done this with my own code explicitly calling mlock) If you don't explicitly lock things into memory, file I/O can and will cause idle pages to get pushed out. It happens less often if you manipulate swappines. -- greg

...gt; Bad news is, that iozone is still the same. There might be some > misunderstanding. > > I have to cases: > > 1) cache=unsafe. In this case, I can see that hypervizor is prone to swap. > Swap a lot. It usually eats whole swap partition and kswapd is running on 100% > CPU. swappines, dirty_ration and company do not improve things at all. > However, I believe, this is just wrong option for scratch disks where one can > expect huge I/O load. Moreover, the hypevizor is poor machine with only low > memory left (ok, in my case about 10GB available), so it does not make sen...

On 09/14/2018 03:36 PM, Lukas Hejtmanek wrote: > Hello, > > ok, I found that cpu pinning was wrong, so I corrected it to be 1:1. The issue > with iozone remains the same. > > The spec is running, however, it runs slower than 1-NUMA case. > > The corrected XML looks like follows: [Reformated XML for better reading] <cpu mode="host-passthrough">

...previous wrong case. So far so good. Bad news is, that iozone is still the same. There might be some misunderstanding. I have to cases: 1) cache=unsafe. In this case, I can see that hypervizor is prone to swap. Swap a lot. It usually eats whole swap partition and kswapd is running on 100% CPU. swappines, dirty_ration and company do not improve things at all. However, I believe, this is just wrong option for scratch disks where one can expect huge I/O load. Moreover, the hypevizor is poor machine with only low memory left (ok, in my case about 10GB available), so it does not make sense to use that...