All Questions
Tagged with performance centos
67
questions
1
vote
0
answers
91
views
CentOS getting unusable slow over time running at Hyper-V
I run TWiki 6.1 on a CentOS Stream 9-virtual machine hosted in Hyper-V at Windows10. VMs hostanme is "twiki"
System ran for over a year now without any problems but since some weeks its not ...
- 11
0
votes
0
answers
1k
views
MDADM Nvme raid Slower than traditional HDD, need enlightenment
I have setup server about 20 days ago with new nvme, before setup raid mdadm the two Nvme samsung 980 pro 1TB i test bench have IO speed average 1.5G/s each nvme, but after creating raid 1, IO nvme ...
- 1
0
votes
2
answers
1k
views
File transfer between servers seems slow
I have two servers both running Rocky Linux v8.4, one hosts a raid drive that I use to back up a (very) large raid drive mounted on Server A as /home.
Server A (with the large raid of 70TB mounted as /...
- 1
0
votes
1
answer
62
views
Tools for testing all aspects of service speed
We have some strange issues on our CentOS LAMP server where there are occasional severe 4-30 second delays in service despite the server being relatively low load at the time. Is there any tool for ...
- 135
1
vote
1
answer
285
views
Is my server drive on SATA2 or SATA3 based on this output?
smartctl output:
# smartctl -a /dev/sda | grep SATA
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
dmesg output (empty):
# dmesg | grep SATA
hdparm output:
# hdparm -I /dev/sda | grep ...
user555159
1
vote
1
answer
915
views
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 ...
- 123
2
votes
0
answers
56
views
Why Does "yes" have drastically different performance on different ditros? [closed]
I tested yes using pv with following command on two different distros :
yes | pv > /dev/null
Results :
Ubuntu 16.04 : 5.83GiB/s
Centos 7.x : 100MiB/s
Here is my Specs:
1st distro : Ubuntu ...
- 207
0
votes
1
answer
70
views
VPS high traffic load
Hello everyone I am really new on this topic so most of my questions will be trivial.
I buyed a VPS from godaddy which has 4 CPUs 8GB Ram and 200 GB HDD. I set up a one domain and upload my web site ...
- 101
0
votes
0
answers
363
views
centos dedicated server backup strategy for mongodb and elasticsearch db
I have a main server (dedicated CentOS 7, XFS file system, 2X1TB SSD, software RAID1) connected via LAN to my backup server (dedicated CentOS 7, XFS file system, 2X2TB HDD, software RAID1) in my setup....
- 117
5
votes
1
answer
427
views
Server computational slowdown when RAM is used extensively
I have problem with server slowdowns in very specific scenario. The facts are:
1) I use computational application WRF (Weather Research and Forecast)
2) I use Dual Xeon E5-2620 v3 with 128GB RAM (...
- 51
40
votes
5
answers
10k
views
Should I be concerned that swap is being used on a host with nearly 40GB of free memory?
I have a production host, below:
The system is using 1GB of swap, while maintaining nearly 40GB of free, unused memory space. Should I be concerned about this, or is it mostly normal?
- 875
1
vote
1
answer
314
views
How conservative should I be when considering current cache use on a system?
Periodically, as with any large online service, we evaluate the current load on our hardware, and make attempts at "right-sizing" so that we're not paying for severely underutilized hardware.
How ...
- 875
2
votes
1
answer
522
views
MySQL performance problems after hardware upgrade and move to VM
Recently we've ran some (security) updates on our servers and rebooted the machines. Our development server did not came online anymore due to a problem with the GPU (integrated in CPU). We've ...
- 121
1
vote
1
answer
3k
views
Speed: nginx serving static content even faster: fixed folder ; how can I
we run centos and nginx one of latest versions in 2016. We use 1 media directory with some underlying subdirectories. FTTB for php is 200ms which is very fast - but now I discovered that the JS CSS ...
- 147
1
vote
1
answer
2k
views
Why my disk elevator is set to "deadline"
I have CentOS 6.x Linux server with kernel 2.6.32-573.8.1.el6.x86_64.
I did some checks today and I found that disk elevator is "deadline".
[root@srv ~]# cat /sys/block/sda/queue/scheduler
noop ...
- 826
1
vote
1
answer
84
views
Different network speeds from servers on same subnet
I have a pretty strange issue, I'm looking for advice on how I can debug it.
I have two servers (A) and (B) on the same subnet and switch. Server A->B transfers at a full 12MB/s and vice-versa.
...
- 800
4
votes
1
answer
485
views
NGINX Worker Process, Burst Read Speed to only 1918kb/s
I am running an NGINX/1.8 server on Centos6.6 with multiple worker_processes, however while observing iotop I notice they burst up to 1918kb/s Read speed and rarely if at all pass that limit.
I want ...
- 131
26
votes
4
answers
36k
views
NFS poor write performance
I have two machines connected with 10Gbit Ethernet. Let one of them be NFS server and another will be NFs client.
Testing network speed over TCP with iperf shows ~9.8 Gbit/s throughput in both ...
- 611
6
votes
2
answers
7k
views
Which CentOS Version Should I Use?
I have some used rackmount servers (Dell R610, HP DL180 G6, HP DL360 G5) that I intend to use for on demand video streaming in a colocation environment. I would like to have them all on the same OS to ...
- 543
0
votes
2
answers
423
views
Are there any performace gains to using Varnish along php-fpm and nginx? [closed]
PHP-FPM 5.6 and Nginx 1.6.2 would no doubt give maximum performance, at-least speed wise. So, I would like to know if there are any pros/cons to adding varnish cache to gain probably few more speed. I ...
- 9
2
votes
1
answer
2k
views
How to troubleshoot an unresponsive server
I'm performance testing my Java based web application (Grails) that is deployed on Tomcat. The server has the below services running on it:
Apache HTTPD
Apache Tomcat
MySql
RabbitMQ
Even though I ...
- 117
0
votes
1
answer
1k
views
Low upload speed (CentOS 6)
I've been having an issue with my servers upload speed slowing down for the last week. When it first occurred restarting the network service would resolve the slow speeds. The speed would then be okay ...
2
votes
2
answers
3k
views
Lots of major page faults in CentOS
We have a fairly complicated PHP script that's generating a lot of minor and major page faults.
$> ps -o min_flt,maj_flt,time,cmd,pid 4686
MINFL MAJFL TIME CMD ...
- 123
2
votes
3
answers
3k
views
sudden peak in cpu usage
We are running a 4 node/machine elastic search cluster on 12 core, 96gb RAM, 4 spinning disk machines. under normal operation most cpu usage is user and around 5-10%. Every few days, one of the ...
- 71
8
votes
4
answers
23k
views
How do I configure RAID 5, especially stripe size, with 24 x 1.2 TB drives for CentOS 6?
For a Dell R920 with 24 x 1.2TB disks (and 1TB RAM), I'm looking to set up a RAID 5 configuration for fast IO. The server will be used to host KVM VMs that will be reading/writing files of all sizes, ...
- 433
1
vote
1
answer
5k
views
Centos running Apache Tomcat keep getting "java.net.SocketException: Too many open files"
We're running Apache Tomcat 7.0.41 on CentOS 6 with java version "1.7.0_21". We were getting a lot of too many open files errors so I did some research. The consensus was that it was to to with the ...
-2
votes
1
answer
448
views
Streaming Server Network Performance [duplicate]
I have server Linux based on
centos 6.5 final 64bit ,
ram 128 G.B
dual E5-2650 processor
Hard disk : 4 SSD Hard disk RAID-5
Network Speed 1/Gbps
Bandwidth Speed 500/Mbps up to 3/Gbps
My Wbebserv ...
- 17
0
votes
2
answers
188
views
How do I prevent a website on my server causing the whole server to crash [closed]
I have a server with 6GB of RAM and a 6-Core CPU. Number of websites hosted by the server is about 10, but sometimes 2 of them take 100% CPU and almost entire RAM which cause the whole server to crash ...
- 101
1
vote
1
answer
3k
views
Abnormal CPU usage during Disk Write Operations
I have a decent CentOS 6.5 dedicated host (CentOS 6.5/E3-1230 3.2Ghz Quad Core + HT/16GB/Software Raid 1 SATA II/WD2503ABYX/ext4) with the default CentOS kernel and "elevator=deadline" in grub.
I/O ...
- 1,875
4
votes
1
answer
4k
views
Very poor disk performance on KVM node - mdadm raid10
For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization.
I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
- 41
2
votes
1
answer
736
views
Why WHM, New Relic and SSH memory usage statistics different?
I have a Cent OS 6.4 Apache Nginx VPS. I have WHM cpanel. How do I check past 24 hours or 48 hours this server RAM usage?
I use new relic server monitor web application. It reported that, this VPS ...
- 37
1
vote
1
answer
165
views
Advice on web server performance troubleshooting is needed
I'm renting a virtual CentOS based server where I have about 5 active sites running. Several months ago I noticed a significant performance degradation in how my sites are running.
First symptom was ...
- 11
0
votes
1
answer
86
views
uk vps server route to thailand? [closed]
I'm just a Javascript developer using node.js...
My host has got me a vps sever in england. I have had someone test my site loading in england and it is lightning fast. I've also had someone test in ...
- 105
0
votes
1
answer
247
views
current my.cnf configuration
Hello serverfault community,
I have a medium sized VPS on which I run 2 Magento installations, a few static pages as well as several WordPress / Joomla installation - all personal websites and ...
- 1
3
votes
1
answer
3k
views
Too many apache processes in D state
Please see the following screenshot. There are too many apache processes all in D(disk sleep) state with very high ram usage.
Is there a way to know what's causing these processes to stay in D state ...
- 165
0
votes
1
answer
63
views
Should getfacl be running constantly and is it normal for it to be using greater than 90% of available disk I/O?
I've recently been getting alerts from our server monitoring software about greater than 90% disk I/O utilisation.
I installed iotop and there are three instances of the following process showing up ...
- 323
8
votes
4
answers
22k
views
Flush-0:n processes causing massive bottleneck
I have a LAMP cluster that shares files via NFS and occasionally one of them will be stricken for a while when mysterious flush processes start appearing.
Can anyone help me? The only way to resolve ...
- 731
21
votes
2
answers
35k
views
jbd2/dm-0-8 consuming all I/O
What is jbd2/dm-0-8 and why It is consuming all my I/O usage and causing I/O wait?
Is there anyway to disable this?
Bonnie++ results: http://pastebin.com/iQCWP1qp
$ sudo hdparm -t /dev/sda1
/dev/...
- 355
0
votes
1
answer
851
views
Mysql and Apache don't free memory after ending connections
My server goes down repeatedly. using htop I found that mysql and apache use almost all of RAM memory. When I restart apache everything is ok, but after a while httpd and mysql take all memory as you ...
- 101
3
votes
5
answers
559
views
What should I do with all my free ram? [closed]
I have a weird kind of problem. I host a small webshop, it´s nothing big perhaps 20 visitors per day and a few orders per week. I will probably expand it a bit but I doubt it will grow very large.
...
- 41
0
votes
1
answer
288
views
file read performance degrades as number of files increases
We're observing poor file read IO results that we'd like to better understand. We can use fio to write 100 files with a sustained aggregate throughput of ~700MB/s. When we switch the test to read ...
- 227
1
vote
1
answer
2k
views
Dovecot high disk io
We're having some major issues with our mail server, normally after a reboot (but not always) where disk io will shoot up from an average 50-100mbps, to 200-300 mbps.
I've narrowed it down to dovecot,...
- 193
1
vote
1
answer
2k
views
Are intermittently slow disk read speeds ever caused by the OS itself?
I'm noticing intermittently slow disk read/write speeds on my CenTOS 5.x VM.
Sometimes hdparm will report:
/dev/sda3:
Timing buffered disk reads: 6 MB in 3.03 seconds = 2.04 MB/sec
Other ...
- 11.9k
3
votes
2
answers
2k
views
LatencyTop on Centos 6.2
What do I need to do to get LatencyTop working on Centos 6.2?
Does it involve compiling a debug kernel with some extra flags?
Both the man page and the website are very short of information.
Thanks!...
- 387
8
votes
1
answer
14k
views
How should I tune apache when I see high CPU, but low memory usage?
My CentOS web nodes (LAMP stack) are experiencing high CPU usage but low memory usage. Nearly all of the processes are apache. I know I could just add additional web nodes until my cpu usage becomes ...
- 420
4
votes
1
answer
3k
views
dd oflag=direct 5x fast
I have Centos 6.2 in server with this specs:
2xCPU 16 Core AMD Opteron 6282 SE
64GB RAM
Raid controller H700 1GB cache NV
- 2HD 74GB SAS 15Krpm RAID1 stripe 16k (OS Centos 6.2) sda
- 4HD 146GB SAS ...
- 76
1
vote
1
answer
714
views
High Steal Time utilization on Apache Linux Server
I have a CentOS "development / testing" server that runs extremely slowly. It's running Apache and Mysql using PHP. Top reports that 98% of the CPU utilization is frequently spent on "st" - Steal Time....
- 506
5
votes
1
answer
863
views
Speed of different Linux distros - why the difference?
I have a piece of multi-threaded software which runs at different speeds under the latest ubuntu server, redhat enterprise and CentOS - all installed on the exact same server for comparison.
Ubuntu ...
- 71
1
vote
2
answers
694
views
Why does "cat /dev/null" and "ls" take 5 seconds to load?
One of my web servers is responding very slowly. Even to simple unix commands. Can you help point me in the right direction to debug?
Here's a crazy example:
# cat /dev/null
This command (...
- 420
1
vote
1
answer
2k
views
How to change the Plesk default theme? [closed]
We use Plesk 10.4 for our shared hosting server. How can I change the Plesk theme ?
branding_theme: command not found
Found here: http://download1.parallels.net/Plesk/PP10/10.1.1/Doc/en-US/online/...
- 13