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

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0
votes
2answers
31 views

Very high First Byte Time

A client of mine which I will be completely re-building the site for, is having some major speed issues with the current site. It takes on average 4.4 to 4.8 seconds before the First Byte Time to ...
0
votes
0answers
17 views

How to find out what is blocking requests on Apache2

I'm running a website on Apache 2.4.9 that creates thumbnails of images a lot and when users browse the website they create cca 100 requests per page. Thumbnails are returned by PHP script that has to ...
29
votes
9answers
7k views

How to [politely?] tell software vendor they don't know what they're talking about

Not a technical question, but a valid one nonetheless. Scenario: HP ProLiant DL380 Gen 8 with 2 x 8-core Xeon E5-2667 CPUs and 256GB RAM running ESXi 5.5. Eight VMs for a given vendor's system. ...
-1
votes
0answers
39 views

Reduce Nginx's response times

I'm running a VPS with 1GB with Debian 7. Nginx's response time for static HTML files are around 300-500ms, which seems relatively high, because other static files (CSS/JS) are served in 75-125ms. Is ...
2
votes
1answer
32 views

What is the correct way to track and monitor Exchange DB replication “pressure” over time?

I want to determine if some databases are overloaded or unbalanced, and think that looking at the transaction logs created per database over time would tell me which DB is at risk of missing RPO ...
9
votes
3answers
703 views

Why is my RAID1 read access slower than write access?

I have done some simple performance tests and it seems that reading from my RAID1 is slower than writing: root@dss0:~# for i in 1 2 3; do dd if=/dev/zero of=/dev/sda bs=1048576 count=131072; done ...
1
vote
1answer
49 views

6 times slower disk write in RAID10 on Ubuntu 14.04 after rebuild

OS: Ubuntu 14.04 LTS Software Raid 10: 4x120Gb Intel 530 SSDs Initial tests: 1.2 GB/s Write 5.2 GB/s Read I did some tests to check if everything will go alright with a failed disk: I set as ...
0
votes
0answers
15 views

MySQL Workbench InnoDB Buffer Usage at 100%, always

The InnoDB Buffer Usage graph is always at 100%. I believe this started to happen when I changed MySQL's temp folder to a much bigger drive, does that make sense? I suppose the thing to do in this ...
12
votes
7answers
542 views

How do storage IOPS change in response to disk capacity?

All other things being equal, how would a storage array's IOPS performance change if one used larger disks. For example, take an array with 10 X 100GB disks. Measure IOPS for sequential 256kb block ...
-8
votes
0answers
29 views

How to improve site performance [closed]

I have an online store. My question is, how can I optimize the performance of the site, and to keep it up and running when I have many users sending requests at the same time ? How can I make my site ...
0
votes
0answers
10 views

sar -b reports much too high statistics, are the I/O counted twice?

On a Linux server sar -b reports much too high read block statistics, sometimes 3.500.000 readb/s peak and around 2.500.000 readb/s sustain, which makes more that 1 gigabyte/s (according to the sar ...
0
votes
1answer
21 views

pagefile and disk space monitoring on server 2012

I have had a server crash recently because of the disk space. Here is what I have: a Hyper-V 2012 server with 1 win 2012 image physical disk is 500GB server uses 800GB It was OK for half a year but ...
3
votes
1answer
157 views

Upstart: Why two processes when running as a different user?

I want to keep a nodejs app running, so I followed this: http://howtonode.org/deploying-node-upstart-monit and installed Monit and Upstart which have been working perfectly for a couple of months. I ...
3
votes
1answer
60 views

Can rsync display current average speed?

When I'm transferring large quantities of data using rsync, it would be helpful if I could have the average speed up until now at a glance, rather than a bunch of different speeds for each file.
-4
votes
0answers
43 views

Make a WHM server handle 10k users at once [duplicate]

How do you get a Level 4, Media Temple Developer VPS, running WHM/Cpanel to handle 10k users at once? Our ole' HostGator Dedicated was able to handle it, but this one can't even handle 2k, probably ...
0
votes
1answer
17 views

Performance Monitor for ASP.Net applications

I have an IIS hosted ASP.Net site which is experiencing timeouts. I would like to be able to monitor it from every angle but I'm not sure where to start with configuring PerfMon counters. Does anyone ...
0
votes
0answers
69 views

Server 2012 slow performance on ESXi 5.5

I'm having performance issues with a virtual Server 2012 that is installed on an ESXi 5.5 (HP-ESXi-5.5.0-iso-5.71.3). The hardware server is an HP ProLiant DL380p Gen8. The server 2012 is acting as ...
3
votes
1answer
31 views

Optimal RAID10 configuration for 8 disks and two volumes?

I have an Open-E file server with 8 SAS disks and a MegaRAID 9271-8i controller and I want to configure two logical RAID10 volumes of identical size. One volume has about 66% write access and 33% read ...
2
votes
0answers
32 views

actual disk iops and write merging

/dev/sdb has LVM and exposes a single logical volume, dm-0. While writing to dm-0, /proc/diskstats reports: # of writes completed sdb 29646717 dm-0 131315099 # of writes merged: sdb 101668283 dm-0 ...
3
votes
1answer
31 views

Is it possible to view average system performance/load over time on a default installation of Windows Server?

Without previously configuring collector sets, is there any record of performance metrics kept on a default installation of Windows Server? I have been tasked to evaluate the load on a particular ...
0
votes
0answers
12 views

SMI generation / detection in GRUB / real mode vs. in Linux

I'm trying to get an idea of the frequency and duration of SMI events on a Supermicro X10SAE C226 board (2.0a BIOS) with E3-1245v3 Haswell CPU. The Intel BIOS Implementation Test Suite (BITS) SMI ...
0
votes
0answers
64 views

Strange ASP.NET Queue Performance Counters Behavior?

We have an ASP.NET 2.0 site running in classic mode. I am seeing very strange behavior in the performance counter values. Perhaps these are bugs (I've been all over Google trying to verify this, ...
2
votes
3answers
107 views

Mysql crashing, oom-killer, out of memory, tuning issues?

I just moved all of my websites to a new server with 4GB RAM. Almost immediately, mysql started crashing, and at one point, didn't reboot which caused a major outage (since I didn't notice until ...
0
votes
1answer
27 views

How to measure TCP connection time in Linux

I want to measure the overhead in creating a TCP connection. I know of many tools like hping and netperf, but they seem oriented at measuring latency. I want to know how long the 3-way handshake ...
-1
votes
2answers
67 views

Count of Unix users: how many is too much? [closed]

I know about Postfix MTA configuration concepts: there's tree of them and the last one is most-appropriate only because it doesn't require new Unix user to be created for new mailbox creation. From ...
0
votes
1answer
46 views

Install Winsat on server 2012? Windows System Assesment Tool

I use winsat disk to see my disk read / write speed windows 8 and it works great: cmd : winsat disk -drive c Can this be used on windows server 2012?
1
vote
1answer
75 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 ...
5
votes
2answers
346 views

Why would Linux VM in vSphere ESXi 5.5 show dramatically increased disk i/o latency?

I'm stumped and I hope someone else will recognize the symptoms of this problem. Hardware: new Dell T110 II, dual-core Pentium G850 2.9 GHz, onboard SATA controller, one new 500 GB 7200 RPM cabled ...
-4
votes
2answers
59 views

How can I optimize my ajax calls to deliver at 60ms.

I am building an autocomplete functionality for my site and the Google instant results are my benchmark. When I look at Google, the 50-60 ms response time baffle me. They look insane. In ...
3
votes
2answers
227 views

Best practice on Linux servers and CPU/power throttling?

I am running a couple of Debian 6 (2.6.32) and 7 (3.2) Linux servers and all of them have energy saving settings enabled in their BIOS. Furthermore Linux shows that the CPUs are throttled if the ...
3
votes
0answers
66 views

Nginx + unicorn + spdy + performance testing

I have a ruby on rails website that is hosted on unicorn webserver behind a nginx reverse proxy. I want to evaluate if using spdy will enhance my performance under this setup. Specifically, I need ...
0
votes
1answer
45 views

S/W RAID6 and 4k sector format — slow resync

I'm looking for reason why Linux software RAID-6 re-sync is much slower than I expected. I have used 6 WDC WD40EFRX HDDs (with 4k physical sectors) to create RAID-6 array. $ sudo mdadm -v -C ...
0
votes
2answers
76 views

How can I find my peak bandwidth usage over a period of time?

I am about to change Dedicated Server providers. My current provider says the uplink is 500M. The (potential) new host offers by default a 100M uplink and charges an extra $100/Month for a Gigabit ...
-1
votes
4answers
502 views

How to explain to users the difference between Xeon and i7/Consumer CPU [closed]

I know that these 2 CPUs, given the same clock speed are still different due to many different factors, but realized I didn't really have enough knowledge to explain it clearly. I assume caching and ...
-2
votes
1answer
65 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 ...
0
votes
0answers
104 views

On a system with 64GB mem the Linux Buffer run full while copying with dd to dev null and io stops till manual drop_caches

I am running a server with linux software raid 10. It is a dual CPU system with 64GB Ram. 2x16GB dimms related to each of the CPUs. I want to use dd to backup kvm virtual machines and run into a ...
2
votes
2answers
290 views

Windows Server 2003 r2 vs 2008 r2 - Performance for SQL Server [closed]

First off, I'm not a sys admin, just a programmer frustrated by poor server performance… We’re currently running a VM (I believe the host is Win Server 2008) on a newer E5-2650 CPU, 24 GB RAM, at ...
0
votes
0answers
14 views

How to compare and state performance on virtual server instance?

I want to report performance statistics about an algorithm that runs on a virtual server instance with Ubuntu on it. I measured runtime and maximum memory usage but I want to give a statement about ...
2
votes
2answers
168 views

Is there anything I can do to decrease waiting time for my static http requests (in chrome's network panel)?

I am running amazon aws ec2 micro instance on Ubuntu 14.04 with apache 2.4.9. The reason for having this instance is just to test and to solve some bugs before rolling up the project. Currently there ...
2
votes
2answers
86 views

Azure IO performance

We have a number of Windows Server virtual machines that we use for .NET and Java development and QA. I find Azure attractive for the obvious reasons but mainly for the opportunity to reduce ...
0
votes
2answers
87 views

Debugging slow transfer rate from server

I'm trying to explain this as simple but documented as possible. This is not exclusive to this server or my current ISP. I've seen the same exact issue over the years while being with different ISPs ...
8
votes
2answers
258 views

Do unused application pools in IIS affect performance?

Due to a major update in our architecture, we now have a few unused application pools under IIS (there are no web sites mapped to them). I understand how it can a good idea to remove them just to ...
0
votes
1answer
51 views

Ignore utm_* values with varnish?

Can I 'ignore' query string variables before pulling matching objects from the cache, but not actually remove them from the URL to the end-user? For example, all the marketing utm_source, ...
1
vote
2answers
181 views

NFS Over OpenVPN: Top Performance Boosters

I have two VPS's - One is running 2008 Server R2 and the other is a Ubuntu 12.04 installation. I am using the Windows VPS for RD sessions for Quickbooks and a couple other apps and using the Ubuntu ...
1
vote
0answers
39 views

IRQ not handled by all CPUs

I have a problem about balancing irq. I took irq numbers from /etc/interrupts and assigned each irq to each of 24 CPUs as this tutorial says for i in {143..166};do cat /proc/irq/${i}/smp_affinity; ...
0
votes
0answers
75 views

Trying to find bottleneck… 60k onsite visitors

I know this will be hard, but I'm willing to try the Q&A route. I have a Wordpress site that currently has 60,000 visitors on the site at once. I'm using an EC2 m3.xlarge, php/php-fpm 5.5.10, ...
3
votes
1answer
118 views

Filesystem performance degraded during RAID rebuilding

So quick question - our RAID6 array is currently rebuilding and there is a VERY noticeable filesystem performance hit (home directories are NFS mounted on the array). I'd sort of expect that, given ...
4
votes
1answer
136 views

Mail Server Storage Backend: Filesystem VS Database

I am trying to compare mail server software to decide which to use at the ISP where I work. I'm confused mainly about which storage backend is better for such use (again, at an ISP, i.e expected large ...
4
votes
6answers
356 views

When is it time to add more cores to your virtual server? [closed]

I have a Linux (RHEL 5.8) server with Java 7 and Tomcat 7. The performance is poor, and I am pretty sure it's the DB queries that are slow. We have 2 cores right now, and load average never exceeds ...
3
votes
1answer
86 views

iozone: 5 concurrent threads random read of 300K blocks does more ops/s than using only one thread, what could be the underlying reason?

The partition is in RAID1 using software RAID. Command line used: iozone -s 190g -r 300k -O -b test_file OPS Mode. Output is in operations per second. ...