Questions about server hardware and software performance, or network performance.

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4
votes
0answers
53 views

Higher TCP latencies in the latest versions of Linux

In my research group, we recently upgraded the OS on our machines from Red Hat 6.2 to Debian 8.3 and observed that the TCP round trip time through the integrated Intel 1G NICs between our machines had ...
-2
votes
0answers
13 views

server capabilities for 2000 active users [duplicate]

I have a CentOS 7 with Apache2 and a Drupal application with a MariaDB database. The application must be available for 2000 users and sometimes about 1800 users will be using it simultaneously. I was ...
-1
votes
0answers
13 views

fio results of performance measurements (esxi+RAID10) better under Windows than Linux

Summing up On same hardware: fio, Debian 8 on bare metal: read : bw=11973KB/s, iops=1485, clat 99.00th=[ 758] fio, Windows 2008 R2 in ESXi 5.5u2 VM: read : bw=43277KB/s, iops=5398, clat 99.00th=[ ...
1
vote
0answers
21 views

Want can be the cause of high number of nfs_lookup requests?

Since a recent linux kernel upgrade (3.2.78 on Debian Wheezy) on both my NFS clients and NFS server, I'm seeing really high increase (10 to 20 folds) in the number of nfs_lookup requests from the ...
1
vote
0answers
27 views

SSD bandwidth issue and analysis

I have Intel's P3700 SSD mounted on a Lenovo x3650 M5 server with two Intel Xeon E5-2630 v3 CPUs. The server is running Ubuntu 14.04 with 4.6.4 Kernel. I've been using fio to benchmark the SSD using ...
-1
votes
0answers
25 views

Windows power management destroys performance [migrated]

I'm using Haswell i7-4790k on a gigabyte Z97-HD3 board with Windows 2012R2. Single threaded cpu-intensive workloads do not cause the Maximum Frequency cap to be lifted when the "Balanced" or "Power ...
0
votes
0answers
8 views

Redis Performance Tanks as Number of Nodes Increases

Strange problem. We have 6 nodes behind a loadbalancer. They are high-spec VPSes running Ubuntu. On a separate node we run Redis. Further nodes run MySQL. The whole LAMP setup hosts Magento. ...
5
votes
0answers
126 views

Suddenly slow RAID performance

We recently noticed our database queries have been taking much longer than usual to run. After some investigation, it looks like we're getting very slow disk reads. We've run into a similar problem ...
3
votes
1answer
31 views

KVM direct disk access vs raw files

I have to setup 14TB of raid storage space (which just shows up as /dev/sdb). My question is: Is there any impact on performance from a kvm guest if I create ext4 on this large drive directly, mount ...
-5
votes
0answers
20 views

What specification server can handle 1 million mySQL queries and 5 million PHP scripts daily? [duplicate]

What kind of specification would I need for running 1 million mySQL queries and 5 million PHP scripts daily (with 80% of the load being between 8am and 10pm). I know databases can require massive IO ...
-1
votes
2answers
38 views

RAID0 SSDs slow on HP ProLiant

TL;DR Is the RAID controller on the HP ProLiant DL360 G7 known to be slow or problematic? My RAID0 set is performing horribly. I have an HP ProLiant DL360 G7. It came with a 160GiB SAS HDD, and I ...
2
votes
2answers
97 views

Does it involve network to copy a file within a NFS share? [closed]

I am assuming the following ways to copy a file with in a NFS share: Process 1: The client requests for the data to be copied from NFS share (if cache is not there) and the chunks of data are ...
0
votes
1answer
68 views

NGINX Reverse Proxy, Config Video(MJPG) Stream to use a single connection to the Backend Server

I have a question/problem weather it is possible to configure a NGINX Reverse Proxy so that it does not Proxy every Request of a Video Stream to the Backend Server, instead Opening a Single Connection ...
2
votes
0answers
15 views

Data throughput/latency and poe performance in TPLINK TL-SG2424P 24 ports POE Managed Switch

I recently bought a TPLINK TL-SG2424P 24 ports POE Managed Switch. At the moment I'm going to use it with only a handful of access points, no more than 4 or 5, at least until the end of the year ...
-3
votes
1answer
28 views

Has my RAID drive failed?

I checked the output of my server today and it said: root@s01 [~]# mdadm --detail /dev/md1 /dev/md1: Version : 1.1 Creation Time : Sat Jul 7 18:23:24 2012 Raid Level : raid1 ...
0
votes
1answer
29 views

I/O scheduling on LVM on dm-crypt

I have the following setup: Stock Debian stable (Linux kernel 3.16.7) running on Dell PowerEdge R320 Two SATA hard drives in RAID1 on a PERC H310 Mini controller, visible as /dev/sda dm-crypt target ...
11
votes
3answers
1k views

Effect of distance from server

I have a web server in Ireland (Amazon AWS). This server appears fast from Germany (orange line) but slow from the USA (black line). The HTTP request used for the test is the same. I think this is ...
2
votes
3answers
40 views

Disk I/O and load average peaks once every hour

We have updated our server from Debian Wheezy to Jessie and from php5.6 to php7.0, but now we have a disk I/O and load average peak exactly every hour. The exact time depends on the system start time. ...
1
vote
1answer
30 views

Seeking inside file performance under BTRFS with LZO compression

I am planning to use btrfs on a 50 TB RAID6 array and I want to enable lzo compression. This is for bioinformatics setup where lots of seeking within large (1 TB -- 20 TB) files occur. (The software ...
2
votes
0answers
32 views

Calculation of Xeon server memory bandwidth

I am looking at a dual socket server based on the Intel(R) Xeon(R) CPU E5-2640 v3 @ 2.60GHz The configuration looks like this. 4 memory channels per socket DIMMs are 8x32 GB DDR4 2133/1866 modules ...
0
votes
0answers
8 views

Recommended Hardware for a school lab LTSP [duplicate]

currently I'm working on a project for a elementary school's computer room/lab. They have a lot of old computers (AMD Athlon CPU f.e.) with WinXP. The teachers are afraid of using that insecure ...
0
votes
1answer
51 views

Does the Dell backplane affect the speed of the drives?

I've already checked the following questions but couldn't find an answer: Does the backplane on an HP server have any impact on the speed of the drives? 3rd party SSD drive in HP Proliant server only ...
0
votes
0answers
16 views

How to check that VMWare virtual machine is receiving sufficient resources from the physical server?

We have VMWare virtual machine in data center but applications on it suddenly started to be slow after one weekend. We are considering possibility that data center has moved virtual machine to other ...
0
votes
0answers
13 views

Sar command “sar -n EDEV -f /var/log/sa/sa16 -s 11:00:00 -e 15:00:00”

sar -n EDEV -f /var/log/sa/sa16 -s 11:00:00 -e 15:00:00 I am using above command on Red Hat Enterprise Linux Server release 5.9, and below is the output to that:(Dev error form 11 am to 3 pm). I have ...
2
votes
0answers
74 views

Poor performance with docker internal DNS

I have a problem with docker internal DNS. On one of docker container dns server is so slow that it time out most of the queries. Docker is installed in KVM virtual machine and I have several ...
0
votes
1answer
40 views

Performance comparison of single RAID vs multiple filesystems

I'm trying to get maximum sequential disk throughput for an application on my Linux server. It has 7 SATA disks that I could put in one RAID0 or RAID5 using a hardware RAID controller (HP P420i). Or, ...
0
votes
2answers
66 views

Confused about Azure Storage Performance

In my experience so far with Azure the biggest bottleneck seems to be Storage performance. I did a few tests with Crystal Disk Mark and as you can see below the performance is very poor. Especially ...
0
votes
0answers
22 views

How can I launch graph500 benchmark on nVidia GPU with CUDA?

How can I launch graph500 benchmark on nVidia GPU with CUDA? There is written: https://devblogs.nvidia.com/parallelforall/gpus-graph-predictive-analytics/ At the IEEE Bigdata conference later in ...
0
votes
0answers
8 views

What resources spent symlinks? [duplicate]

I'm working on a web application that makes use of symbolic links. It is a SaaS application where for each user generates symlinks of a core folder and serve them on a new hostname selected by the ...
0
votes
1answer
37 views

/proc/diskstats: No such file or directory

Trying to get some disk performance metrics (in particular, using munin), found that /proc/diskstats does not exist. Tried yum provides '*/diskstats' but nothing except munin was found. CentOS ...
2
votes
1answer
69 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 ...
3
votes
2answers
57 views

How to compare mainframe CPU performance?

I am working with an application that runs on tomcat in OMVS. It run terribly on one mainframe, and adequately another another. Is there a way I can compare the CPU of the two mainframes as a ...
0
votes
0answers
30 views

small client-server app & db install location

We're running Server 2008 R2 on dual 2.8 GHz processors with 32 GB memory and a partitioned 1 TB, 3-disc RAID. Seems plenty robust for our purposes. Our primary application, however, has been lagging ...
1
vote
0answers
36 views

Extremelly slow SMB download, normal SMB upload over LAN

I've been having an issue with a Windows 10 client experiencing very slow download speeds over SMB, but normal upload speeds. I'm able to demonstrate this using LAN Speed Test with the following ...
0
votes
1answer
162 views

High CPU Load on Synology by smbd

I have a Synology DS213j which I access through a VPN via the build-in VPN Server (I use OpenVPN) using Windows Explorer. Copying files to my local hard drive is very slow in the range of only ~170 ...
1
vote
1answer
26 views

Is there a way to configure sudo to not need to lookup group names / or speed up sssd group name resolution?

I've got a large number of Linux hosts that are connected using sssd to a windows active directory domain for user/group lookup. That mostly works fine except for one problem; sudo From what I'...
12
votes
4answers
1k views

Load time impact of htaccess

There are in general two possibilities of handling stuff on Apache: make configurations for folders one by one using htaccess file to fully resign htaccess and put all the rules into the httpd.conf ...
2
votes
1answer
22 views

Is NUMA always completely NUMA or are there also hybrid systems?

I am working on a high-end server application where performance is critical. Given that servers are often employ NUMA-architectures, the server application also uses NUMA-aware memory allocation ...
0
votes
0answers
36 views

nginx / node server TTFB very high sometimes

I currently have 2 nodes app on a nginx server behind is a mongo db and a elastic search instance. I currently face serious performance issue, this is not related to an overload of number of user, ...
2
votes
2answers
103 views

How can SSD write performance be dramatically different on two identical servers?

I am renting two identical physical servers (at Serverloft). These servers come with 2x512 GB SSD disks, and I've set them up with mdadm in a RAID1. The disks are locally installed in the server. The ...
0
votes
0answers
21 views

Gathering Performance Metrics (RAM, CPU, etc) AWS & Azure

We're developing a cross cloud plane performance metric harvester, to collect various performance metrics, but the top 3 being RAM usage, CPU Utilization and Disk Utilization. I know CloudWatch will ...
1
vote
2answers
51 views

How to balance elasticsearch (java) on a very powerful machine?

On a 16 core XEON class, 128GB RAM RHEL server I want to deploy elasticsearch. What is preferable performance-wise? Have a huge elasticsearch process to use all resources on the native host? Break ...
2
votes
0answers
9 views

Move htaccess rules to apache configuration files

I'm running a website with Joomla on a dedicated server (Debian), and i've read that moving .htaccess rules to apache2 configuration files may result in a good performance improvement (Apache HTTP ...
0
votes
0answers
40 views

How to find which db/collection/query triggers disk read?

We're running a MongoDB 3.0 server with multiple users accessing it and we're experiencing very frequent disk reads by mongod process utilizing our SSD drives to 100% During these peaks the page ...
0
votes
0answers
23 views

We are constantly getting CPU Spikes and site slows down [duplicate]

Our website works fine and fast, then out of nowhere cpu spikes to 100% site becomes really slow and after 10 minutes it is back to normal, this is constantly happening. How would one diagnose this? ...
1
vote
1answer
231 views

Huge performance penalty in gbit link with ip forwarding / masquerade through clear VPN tunnel

I have a problem with IP forwarding between my home computer and a remote server (from online.net). My home connection is a 1 Gbit/s FTTH and the remote server has a 2.5 Gbit/s bandwidth. The context ...
-1
votes
1answer
52 views

mpm_prefork values for 2-4 GB RAM [duplicate]

I have bought new linode (1GB). On this page :https://www.linode.com/docs/websites/lamp/install-lamp-on-ubuntu-16-04 Linode says: Below are the suggested values for a 1GB Linode: File:/etc/...
4
votes
2answers
94 views

Massive performance degradation on sustained sequential write

I'm in the process of migrating data into LUKS partitions. Now that the operating system drive is running off LUKS, I tried to start migrating the data drives. Then the server stopped responding. ...
0
votes
0answers
32 views

RAID 1 disk sequential read/write speed inconsistent

I have an issue with 2 of my servers, and I'm not sure what's going on. The setup is the same for all my servers: C: 2 SSD 512GB in RAID-1 D: 2 SSD 512GB in RAID-1 The servers are DELL's, the ...
1
vote
0answers
14 views

Windows Server Backup Snap-In Initializes/Moves Extremely Slowly

I have an SBS-2011 box. The WSB snap-in consistently takes 10+ minutes to move beyond 'Reading Data'. After the snap-in finally initializes I experience the same behavior when performing a recovery. ...