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

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2answers
50 views

How to limit disk performance?

I am load-testing a web application and studying the impact of some config tweaks (related to disk i/o) on the overall app performance, i.e. the amount of users that can be handled simultaneously. ...
3
votes
3answers
678 views

How to troubleshoot performance issues of PHP, MySQL and generic I/O

I have a WordPress based website running on a shared hosting. Its response time is very decent (around 2s to retrieve the HTML page and 5s to load all the resources). I was planning to move it to a ...
1
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0answers
144 views

Why does Process Explorer cause highly targeted failure of some applications / basic UI functions in a high-power EC2 Windows instance?

Update: I have determined that Process Explorer itself - the program I am using to debug a performance issue - seems to be the cause of the issue. See note, with updated question, at end. I am ...
2
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2answers
279 views

Sendmail slow to accept emails

I have a PHP web app which is using SMTP to sendmail on localhost to send email. I would like sendmail to accept the mail request immediately and queue it for later sending, as I don't want to have ...
1
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0answers
25 views

Is it worthwhile, for performance reasons, to surround Apache mod_rewrite checks with Directives like Location, DirectoryMatch, etc?

I currently have a number of Apache rewrite rules using mod_rewrite (Apache 2.2). When I turn on rewrite logging I see a number of evaluations of rewrite conditions for files that have no chance of ...
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0answers
95 views

Boot disk with VMFS read/write driver

I want to rule out the ESXi kernel being the cause for my terrible 15MB/s write speed on the local VMFS datastore. I am using a Dell PERC H710 RAID controller, and would like to boot from a boot disk ...
2
votes
1answer
372 views

VMware Performance Monitor: How does aggregation work for VM Processor\% Processor Time

I'm monitoring a Windows Server 2008 R2 SP1 VM running on vSphere 5.1 for CPU bottlenecks. I'm using Performance Monitor and configured a few counters. Two of which are Processor\% Processor Time and ...
2
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3answers
2k views

Performance difference between compiled and binary linux distributions/packages

I was searching a lot on the internet and couldn't find an exact answer. There are distros like Gentoo (or FreeBSD) which does not come with binaries but only with source code for packages (ports). ...
1
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1answer
1k views

Slow Write Speed on ESXi host

I have an ESXi 5.0 free host with an internal datastore of 7.2K 5 disk RAID 5 using a PERC 710 mini RAID controller in a Dell Poweredge R620 Server with 32GB Ram and a 12 Core Xeon. I seem to get ...
3
votes
1answer
11k views

what is acceptable datastore latency on VMware ESXi host?

Looking at our performance figures on our existing VMware ESXi 4.1 host at the Datastore/Real-time performance data Write Latency Avg 14 ms Max 41 ms Read Latency Avg 4.5 ms Max 12 ms People ...
0
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3answers
975 views

Linux server became extremely slow

I have a file sharing website, and my files hosted in a server with those system specifications: 32GB RAM 12x3TB 2x Intel Quad Core E5620 I have files in this server up to 4gb for each file. 446gb ...
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0answers
145 views

How to find out which process is hogging the linux server?

We have a RHEL server. Today it suddenly became slow. Symptoms - It was responding slow to ping queries from other server. When I try to login using ssh, it was taking about 10 seconds to login. I was ...
3
votes
2answers
125 views

Can more memory than I need slow down my server?

We're about to install a memory intensive application and will purchase a server for it. The server will have at least 4 CPUs, with multiple cores. While the application is memory intensive, the ...
4
votes
4answers
2k views

Disk performance below expectations

this is a follow-up to a previous question that I asked (Two servers with inconsistent disk speed). I have a PowerEdge R510 server with a PERC H700 integrated RAID controller (call this Server B) ...
0
votes
1answer
2k views

Upgrading a PERC h310 to a PERC H710 mini RAID controller on a Dell R620

I have an ESXi 5.0 Free license host using an internal Datastore (RAID 5, 5 Disk) that was configured with a Dell PERC h310 RAID controller. The disk performance was very poor, so I upgraded to the ...
2
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0answers
74 views

IBM xSeries 306 CPU Speed

I have an IBM xSeries 306. The system has been flawless until a week ago. It's a Pentium 4 Dual Core CPU. The CPU speed is 3.20 gHz. Now, it shows 4.26 gHz or 2.16 gHz when the POST screen comes ...
3
votes
2answers
1k views

Large keepalive_requests values are severely slowing-down Nginx

When running a bacon (43-byte transparent pixel) load test on Nginx, we have tried several keepalive_requests values (from 10 to 100,000) and the optimal value seems to be 10. Here are the server ...
1
vote
1answer
682 views

How to erase a SSD to restore factory performance in Linux?

Due to big performance issues with an mdraid-1 array I'd like to pull down from the array one of the devices (Samsung 840 Pro), erase it to restore factory performance and re-add it to the array. The ...
1
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0answers
117 views

big speed difference on a network link with and without VPN tunnel

Scenario: We have a network link between two offices. The link is provided by a third party company through a VLAN on their network, but to us it is totally transparent -as if we had a simple ...
0
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2answers
56 views

Recommended Setup

I have been running into issue with my MSSQL Database setup with speed. Here is my scenario. About 100M Rows Average: 1k Updates Per Second Hard Drives: RAID 10 SSD MDF --Active Time: 0 Log ...
1
vote
1answer
254 views

KVM Slow performance on XP Guest

The system is very slow to do anything, even browse a local folder, and CPU sits at 100% frequently. Guest is XP 32 bit. Host is Scientific Linux 6.2, Libvirt 0.10, Guest XP OS shows ACPI ...
1
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1answer
478 views

Various problems with software raid1 array built with Samsung 840 Pro SSDs

I am bringing to ServerFault a problem that is tormenting me for 6+ months. I have a CentOS 6 (64bit) server with an md software raid-1 array with 2 x Samsung 840 Pro SSDs (512GB). Problems: ...
3
votes
3answers
305 views

MySQL hangs if connection comes from outside the LAN

I have a MySQL Server operating just fine if I access him from his local LAN (192.168.100.0/24). If I try to access hin from another LAN (192.168.113.0/24 in this case) it hangs for a really long time ...
2
votes
1answer
84 views

Understanding %DiskTime in Perfmon

I have a server that's been jumping around 100-700 %DiskTime for the past few days. I understand this indicates an I/O bottleneck -- but what do I do from here? What do I need to check or change in ...
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1answer
156 views

How strongly does the number of processors influence on the performance? [closed]

I use Windows Server 2008 R2 with Hyper-V. I can increase the number of processors in Hyper-V settings (http://www.youtube.com/watch?v=NQCMT-O6bMM). How strongly it will increase the performance? ...
5
votes
2answers
467 views

vCenter Cluster CPU utilisation data inaccurate

We have quite a reasonably sized vSphere 'estate', with 80% of our Windows/Linux servers virtualised, running across six Datacentres. One of my challenges is medium to long term capacity planning, ...
2
votes
1answer
118 views

App slow on Server 2008 r2 but fast on Windows 7

I have an app that runs fast on windows 7, but when I host it on windows server 2008 r2, it's much slower. I've turned power power options to 'Hi Performance' and set optimization to programs rather ...
2
votes
1answer
7k views

Improving OpenVPN Performance

I've been trying to improve my OpenVPN performance and this is my current setup: cat /etc/openvpn/server.conf port 443 #- port proto tcp #- protocol dev tun #tun-mtu 1500 tun-mtu-extra 32 #mssfix ...
0
votes
1answer
97 views

OpenVPN and Performance [closed]

From my understanding RDP is encrypted and so is the OpenVPN connection so that is an encryption in an encryption. My Setup: LAPTOP <---> REMOTE SERVER <---> OFFICE SYSTEM Due to ...
2
votes
2answers
423 views

Strange performance issue with Dell R7610 and LSI 2208 RAID controller

Connecting controller to any of the three PCIe x16 slots yield choppy read performance around 750 MB/sec Lowly PCIe x4 slot yields steady 1.2 GB/sec read Given same files, same Windows Server 2008 ...
2
votes
2answers
1k views

Disk latency within a virtual machine

I've been looking at some performance issues on a clustered virtual machine in our organisation. Actually this problem seems to affect most of the virtual machines I have looked at. Both host and VM ...
1
vote
1answer
168 views

Why does my program run 2-4 times slower on a VPS?

I have a program (Node.js web application on Ubuntu) that loads in about 7 seconds on my home computer. Recently I copied it to a VPS, and there, it loads in 15-30 seconds. I am trying to find out ...
0
votes
1answer
35 views

Is it bad to have two webapps each on different servlet container than both on same, on a production server?

I need to run two webapps on a ubuntu VPS but one(my own webapp) prefers to run in Tomcat & other(Solr webservice) is preferable in Jetty. But I think running a separate server for each webapp ...
1
vote
2answers
42 views

How to exclude requests from unwanted sources

Scenario: Client buys our analytics services and includes our analytics SDK in his mobile app. Users who download the app will start sending us lots of data. When the client stops paying for our ...
0
votes
0answers
15 views

Adding a servers to a domain affects GUI performance of the Server

A very strange situation, we have the following setup. 3 x Terminal servers ( two are 2003 and one 2008R2) 1 x App Server 1 X DC AD 1 X SQL Here's the funny part, all the servers seem to have ...
1
vote
3answers
1k views

slow website load and high memory usage

my site has been slowed down last couple of days ... some image doesn't show up ... i got 408 Request Time-out: Server timeout waiting for the HTTP request from the client couple of times which ...
2
votes
1answer
1k views

How to improve Varnish performance?

We're experiencing a strange problem with our current Varnish configuration. 4x Web Servers (IIS 6.5 on Windows 2003 Server, each installed on a Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Quad Core, 4GB ...
0
votes
2answers
429 views

Disk Cached IO very slow

I have two boxes with exactly same hardware configuration. Both having RAID0 (created using mdadm) over SATA disks. But I am getting different cached reads while testing using hdparm command. $ ...
-4
votes
1answer
236 views

Is it possible to manual change the WIFI link speed? [closed]

In my project, I have a Android smartphone and a router (can be a normal router or use a laptop running Linux or Windows). I need to emulate some traffic jam or signal degradation. I know the WIFI ...
4
votes
1answer
6k views

Poor Disk Performance on VMs; Host using PERC H310 RAID 5

I have a Dell R620 running 5 500GB 7.2K RPM SATA 3Gbps 2.5in Hot-plug Hard Drives in a PERC H310 controller (which I am beginning to regret buying). I am getting awful read/write speeds on Linux ...
2
votes
1answer
936 views

How to achieve multiple NFS/TCP connections to the same server?

I'm trying to maximize the NFS/TCP bandwidth between a Linux client and a single NFS server over a 10Gbps link. Although each NFS mount has its own device (major/minor), everything comes down to a ...
0
votes
1answer
412 views

How can I determine Breaking point of my Web application using JMeter?

How can I determine Breaking point of my Web application using JMeter? I have executed the JMeter Testplan with different concurrent users load. EX. 300 users(0% error), 400 users(7% error in a ...
0
votes
0answers
123 views

Apache Load Balancer With JBoss

I have Apache acting as a load balancer in front of 5 JBoss nodes. When I put a load of more than 200 concurrent users on the environment through my load testing tool, my response times are going ...
0
votes
1answer
4k views

Apache consuming too much CPU and memory

I am having some troubles with CPU loading an memory with Apache Web Server. We are running a Ubuntu Server 12.04 LTS on a Virtual Machine. Our server have the following specs: 8GB RAM; 4 vCPUs ...
1
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0answers
570 views

Amazon RDS: Sudden increase in Read IOPS and Throughput

I am using Amazon RDS to host the databases for my website. I am using the large instances for both my master and my read replica. Everything was running smoothly until suddenly the Read IOPS, Read ...
2
votes
0answers
76 views

IIS 6 About 5% of request are very slow

We have a IIS 6 web server on Win2003 The avg requests/sec = 200 The avg cpu utilization = 30% The memory 10% full HDD avg time = 5% I have turned on the logging to see time-taken for each request ...
1
vote
1answer
113 views

Best PostgreSQL HA strategy for 99% read scenario?

I'm in the process of building out a new PostgreSQL (9.3) environment in which traffic hovers around 99% read. We'll have 2 very powerful machines, connected via 1Gb ethernet. With the multitude of ...
0
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0answers
417 views

High disk usage in CSRSS.EXE

I recently started working on the server for a certain software (Tango). The users complained that it recently became extremely low, so I used an application (ProcessHacker) to see the resource usage ...
0
votes
0answers
79 views

Two servers with inconsistent disk speed

I have two servers of identical spec (bought at the same time), except for the drive configuration: Server A: C: and D: drives are partitions on the same 2 disk RAID 1 E: is a 2 disk RAID 0 ...
12
votes
1answer
452 views

ext4 listing of files very slow in one specific directory that contained lots of files before

Background I had a small logrotate misshap... Logrotate would rotate the archived logs by misstake causing a quadratic growth of files in my /var/log/. And by the time I caught wind that something ...