All Questions
Tagged with performance linux
553
questions
1
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0
answers
45
views
Linux Server is slow on running some commands
I have a Linux server and ubuntu 20.04 is installed on it. Kernel version is 5.4.0-163-generic. 24 cores and 32GB RAM.
I have database running on this server which is working without any issue. ...
- 11
3
votes
0
answers
58
views
Reading from software RAID in parallel is slower than it "should" be, given other benchmarks
Note:
I have seen some somewhat similar questions here, but:
none of them concern reading many files in parallel, and
most are 10+ years old and concern no-longer-relevant hardware and kernel ...
- 131
-1
votes
1
answer
31
views
What happens on the server when a multimedia file gets downloading/playing?
I have a video-based website. It gets slow when about 1k concurrent users watch/download a video.
I'm trying to debug it to see what resource is weak to increase it. I executed htop command to see ...
- 99
0
votes
1
answer
116
views
Why MACsec can not reach more than 2Gbits/s?
i am configuring macsec and i have discovered that, when using this protocol to send/received data, the bitrate is so low.
I am using it over a 10Gb network adaptor, using iperf3 it almost reach that ...
0
votes
0
answers
59
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How to figure out what makes a Linux workstation slow?
We have this ThinkPad X240, 8GiB of RAM, an i5 4300U, and a Toshiba SATA SSD. The machine is running Linux Mint 20.3.
The user complains that it is very slow. Mostly when the browser is open and ...
- 81
0
votes
0
answers
206
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LVM Thin pool performance with NVMe
I have 24 Samsung PM1733 7.68 TB and a server platform Gigabyte R282-Z94 with 2x 7702 64cores AMD EPYC. OS: Oracle Linux 8.6, 5.4.17-2136.311.6.el8uek.x86_64
I need this server for testing so I have ...
- 89
1
vote
2
answers
116
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Prefetched Small File Cache
First, my use case: On my Linux-based server I am getting unsatisfactory disk IO performance for small files, and am limited to the approximately 100 IOPS that a 7200rpm HDD will support. This is of ...
- 13
-1
votes
2
answers
401
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nginx and php-fpm waiting for server too long
I am using docker to mount nginx and a PHP-FPM using Phalcon Framework and React as the front end
`upstream fastcgi_backend {
server bfy-%APP_VERSION_UID%_buildify-php-fpm_1:90%FPM_PORT_PREFIX%;
}
...
0
votes
0
answers
71
views
performance issue when linux(ubuntu) work as router with ip_forwarding enable
I'm running a test with this topo: tester---(port1)ubuntu_linux(port2)----tester. I enabled ip_forwarding in ubuntu_linux by : echo 1 > /proc/sys/net/ipv4/ip_forward
The tester is trying to find ...
- 1
0
votes
0
answers
206
views
Poor server performance on Linux Ubuntu 20.04 with PHP-FPM, MySQL, and Redis Server installed
My client’s server has recently started having performance issues. The single website hosted on the server loads very slowly. It is built with WordPress using a custom theme. There are a minimum ...
- 141
1
vote
2
answers
144
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NPS4 on a Threadripper 3960x gives two nodes with no memory at all
I set my 3960x to NPS4 (Nodes Per Socket: 4) mode to experiment with NUMA on Linux. My system has 4 32 GiB DIMMs across 4 channels, so I expected each of the 4 nodes to get one. Instead, nodes 1 &...
- 119
0
votes
0
answers
51
views
What is the Max value for speed limit param in CloudLinux (lve)?
I can see in cloudLinux document that in cpu usage limit section, 150% means 1.5 cores : https://docs.cloudlinux.com/limits/#speed-limit
My question is : for a server with 12 cores, if I want to use ...
- 1
-2
votes
1
answer
114
views
Discovering the speed of data transfer between my server and another server that I don't have access to [closed]
What solution do you have so that I can get the speed of downloading from a server or uploading to a server on the TCP or UDP protocol, which I do not have access to that server? but I have root ...
- 97
12
votes
2
answers
5k
views
How dangerous might it be - and what performance gains may be had - by turning vulnerability mitigations off on non-Internet facing servers?
When a virtual machine Linux host server is non-Internet facing and is used exclusively on a LAN and is using a relatively well tested distribution like Proxmox, how dangerous would it be to turn off ...
- 1,185
0
votes
1
answer
917
views
Nginx cache for frequent and different requests
I have a service.
This service has a GET handle(/api/v1/retrieve_blocks).
This handle's requests and responces are small, no more than 1024 characters.
regular situation:
this handle is constantly ...
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
0
answers
3k
views
sdb: Disk read/write request responses are too high (read > 20 ms for 15m or write > 20 ms for 15m)
I use Zabbix agent to monitor my Linux servers.
I start to receive this alarm:
sdb: Disk read/write request responses are too high (read > 20 ms for 15m or write > 20 ms for 15m)
incident ...
- 1
1
vote
1
answer
24
views
What do results of Linux time wrapper tell me happened to this cp command?
My view on this issue is from the developer side. I write the code that gets placed on a RHEL virtual machine running as one of many in an enterprise system. The filesystem being used is a remote, ...
- 13
0
votes
1
answer
418
views
High util iostat
I have server with oracle db. It works on Dell Unity storage.
The server has very slow disk IO.
How can I fix it?
Here are some details of my server:
OS - OL8
Kernel - 5.4.17 uek
Storage - Dell ...
- 1
0
votes
1
answer
519
views
How to constraint already running interactive processes with cgroup2
My home-server is running some aged hardware (Core i5-3450, software RAID1 on SATA disks) and often has problems when I run performance-intensive things like a compile-job besides "normal" ...
0
votes
3
answers
2k
views
best filesystem for millions of files [closed]
Which Linux filesystem/setup would you choose for the best speed in the following scenario:
a few million files
~3mb file size on average
random access to files
need to get a list of all the files ...
- 31
4
votes
3
answers
4k
views
ZFS performance: Extreme low write speed
I am running a small home server. The specs are:
CPU: AMD Ryzen 5 2600
RAM: 32 GB ECC
System drive: 128GB NVMe SSD
Data drives: 3x 4 TB Seagate Barracuda HDD
The server runs some applications like ...
1
vote
1
answer
469
views
Fragmented directory on ext4?
My ext4 filesystem loses performance when growing.
I have a system storing a lot of image files. This Debian based image server stores image files divided in year folders on 1-2TB disk sets with ...
- 31
1
vote
0
answers
66
views
Couchdb 3.1.1 increases disk latency gradually over weeks
I've been dealing with this issue for weeks now.
I have the followin scenario:
couchdb2.3.1-A <===> couchdb2.3.1-B <===> couchdb3.1.1-A <===> couchdb3.1.1-B
where <===> ...
-3
votes
1
answer
42
views
Is there a program to diagnose and summarize why my mchine is slow? [closed]
Is there a program that will tell me why my server is slow? What is being over utilized? CPU / Memory / Disk / Network ... and what processes are driving that utilization? I want a program that can ...
- 95
-1
votes
1
answer
427
views
Simulate some process IO with fio or other tool
Is there any way to track a specific process and get stats for disk IO such as queue depth, total reading/writing threads, percent of reads/writes and so on?
The main goal is to use all that ...
- 103
0
votes
1
answer
870
views
Ubuntu Server 18.04 slow performance
I use a server with these hardware:
Cpu: AMD Ryzen 9 5950X 16 cores
Ram: 128GB DDR4 ECC
NVMe SSD HD
There I have installed Ubuntu 18.04 LTS with latest kernel. No panels only the following services ...
- 143
1
vote
1
answer
457
views
nginx under high traffic: network goes down when log writes to disk?
An VPS with 2 vCPUs, with Ubuntu 20.04 and nginx.
Nothing changed regarding to loging: neither on nginx, rsyslogd, or journald.
I launch ab (apache-benchmark) from a nearby VPS, like this:
ab -k -c ...
0
votes
1
answer
64
views
What is a dispatcher?
I have a wordpress site that was running slow so I signed up for stackify to get a performance profile of server. I dont get the same slow down on baremetal and localhost running the same site. This ...
- 243
0
votes
0
answers
239
views
What could cause processes to not be active
Running linux and executing a bunch of PHP scripts. I noticed that our CPU usage was pretty low but many processes were sleeping, so started investigating.
AWS EC2 with an S3 bucket.
I can't seem to ...
- 379
1
vote
1
answer
776
views
MegaRAID: performance difference between volumes
I have a MegaRAID SAS 9361-8i with 2x 240GB SATA 6Gbps SSD in RAID1, 4x 10TB SAS 12Gbps HDD in RAID6 and 4x 480GB SATA 6 Gbps SSD in RAID5:
-------------------------------------------------------------...
- 3,327
0
votes
0
answers
71
views
1gb vs 10gb uplink in terms of TTFB
I am about to setup a new dedicated server, I have the option of 1gb vs 10gb uplink with a considerable price difference. I do only have 10 domains on this sever and traffic is not huge. However, on ...
- 1
1
vote
1
answer
141
views
Speed issue on using Linux subsystem search on a Windows server [closed]
I'm performing a search on a Windows server, who has a mapping to my Z:-drive (\\<servername>\<base_directory>). In there I would like to search inside a subdirectory, so we get Z:\<...
- 123
2
votes
0
answers
612
views
Access disk io data in linux without tools like iotop/iostat to find processes or files with IO
We have regularly high load average. With the help of a zabbix agent, I could narrow it down to be mainly because of cpu iowait (and lastly disk io). I am not allowed to install any additional ...
- 121
0
votes
0
answers
29
views
Forcing Linux (Ubuntu 18.04) to deallocate some cache prior to high priority job
I have a server that periodically has to do a high priority job as quickly as possible. I know before hand when the job will need to run. I want to tell Linux to do all it's housekeeping a few seconds ...
- 23
2
votes
1
answer
104
views
MYSQL vs. InnoDB [closed]
mysqltuner output.
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +...
1
vote
0
answers
140
views
disk I/O latency spikes (contains log files from amplify)
Ubuntu 18.04 LTS server, disk is ssd. Application stack is: mongodb, node, nignx and some python.
Server is up 1 month and already had 3 OS disk fails where Ubuntu would go in read only mode. After ...
0
votes
0
answers
43
views
Linux software raid slow until reboot
I am running an debian 10 machine with 3 4tb hdd drives.
Each drive has a 1GB partition for a raid1 for the boot and the rest of the disk is configured as a raid 5 for lvm.
After a while of running I ...
- 101
0
votes
1
answer
45
views
SpectreV1 Mitigation Performance profiling
I am trying to measure the system performance when spectreV1 mitigation is on. I am using stress-ng for that. So far I have tested the system with various stressors like cpu, qsort, str, matrix, ...
- 101
1
vote
1
answer
552
views
Suspicious ksoftirqd_1 process using high cpu [duplicate]
I run this webserver that serves data to a couple of apps. In the last couple of days I have noticed that some requests take some more time than usual, so I did a top to find out what's running and ...
1
vote
1
answer
783
views
Intermittent KVM performance issues causing performance glitches
We are currently hosted on a hosting provider that allows us to set up multiple virtual machines using KVM, where each virtual machine runs on it's own physical box (ie: one hypervisor, one VM with ...
- 111
1
vote
0
answers
674
views
How does avgqu-sz size in iostat output relate to r_await and w_await?
Can someone explain what does avgqu-sz mean in the output of iostat? The manual page states like this.
avgqu-sz:
The average queue length of the requests that were issued to the device.
Can ...
- 333
1
vote
1
answer
654
views
How do I know if SSD is the bottleneck in Linux?
I have a database server which uses a Samsung 840 pro disk. The load is constantly higher than usual, even if there is not much activity on the website. So I suspect the disk has worn out. But how can ...
- 113
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
0
votes
1
answer
60
views
When should we use containerized application on Linux
I would like to create a Linux server but I'm stuck on one question:
How to know when I should use Docker or Lxc for a given application instead of installing it natively ?
For example, on my server ...
- 15
-2
votes
1
answer
72
views
Buy new VPS just for Mysql or upgrade current one and keep the whole stack on the same server [duplicate]
This is not a question about capacity planning, its about mysql performance over local network vs on the same virtual machine (where it needs to share cpu with other processes)
I have a wordpress+...
1
vote
1
answer
639
views
Bottleneck identification using iostat, vmstat, mpstat
I am doing some Apache and MySQL performance tests, then upgrading a single component and running tests again to see where the bottlenecks are. I have a local used server warehouse (Tams in Lindon UT) ...
- 543
1
vote
1
answer
608
views
Virtual machine disk I/O latency spikes
Since past few days I have strange I/O spikes in one virtual machine.
Its
2.6.32-504.el6.x86_64 #1 SMP Tue Sep 16 01:56:35 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux
Red Hat Enterprise Linux Server ...
1
vote
1
answer
126
views
Writes throttled to 500KB/s?
My laptop, running Debian testing, has recently been terribly sluggish at operations involving writing to the disk.
I have no idea where the problem comes from and would love some help tracking this ...
- 133