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

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1
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2answers
350 views

Apache2 BufferedLogs On - anybody using it?

Greetings, I am wondering, whether anybody is using BufferedLogs On with Apache2 and found any issues ? Feature is marked as experimental, but for many years now, so I guess it's rather pretty stable. ...
3
votes
1answer
808 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
1answer
10 views

Perfmon % Processor Time unbalanced

I am somewhat of an accidental DBA, and I'm troubleshooting a SQL Server box where performance has been notoriously poor (as reported by the customer). I was not involved in the initial planning of ...
36
votes
10answers
10k 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. ...
5
votes
4answers
458 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, ...
0
votes
1answer
742 views

Performance Issue Between SQL and IIS on Seperate Machines

First time OP on serverfault, but an avid user of stackoverflow. We have two high-specification boxes, both running Windows Server 2008 R2 Standard. On one we have IIS 7.5, the other SQL Server 2008 ...
0
votes
2answers
32 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
18 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 ...
-1
votes
0answers
42 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 ...
10
votes
3answers
717 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 ...
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 ...
1
vote
3answers
249 views

VOIP and internet connection speeds [cable vs. fiber]

Our office is migrating to IP telephony. We have less than 10 employees that will be using the phones. We currently have cable internet, and they just bumped the speeds: There is a data center ...
1
vote
1answer
53 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
16 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 ...
2
votes
1answer
841 views

BackupExec 12 + RALUS - VERY slow backups

We use Backup Exec 12 and the Remote Agent for Linux/Unix Servers (RALUS) to backup a large RHEL5 system. For various reasons we need to do a daily working set job. These working-set jobs run ...
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 ...
12
votes
7answers
547 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 ...
0
votes
0answers
11 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
22 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 ...
2
votes
2answers
820 views

Changing memory allocator to Jemalloc Centos 6

After reading this blog post about the impact of memory allocators like jemalloc on highly threaded applications, I wanted to test things on a larger scale on some of our cluster of servers. We run ...
7
votes
3answers
2k views

Apache on Win32: Slow Transfers of single, static files in HTTP, fast in HTTPS

I have a weird problem with Apache 2.2.15 on Windows 2000 Server SP4. Basically, I am trying to serve larger static files, images, videos etc. The download seems to be capped at around 550kB/s even ...
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.
3
votes
2answers
228 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 ...
-4
votes
0answers
46 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 ...
2
votes
2answers
681 views

How to delete unknown user profiles remotely?

When user is deleted from Active Directory, it shows as an unknown user. System properties -> Advanced -> User Profile -> Settings... I have to delete it manually all the time. There are more than ...
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 ...
11
votes
6answers
15k views

How can I disable encryption on openssh?

I'm having performance problems using openshh(server) and putty(client) combination to use a remote webproxy. I'd like to disable encryption and test the results to see if it makes a difference. How ...
0
votes
0answers
72 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 ...
2
votes
3answers
115 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 ...
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
14 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 ...
1
vote
5answers
1k views

Windows Server 2008 R2 poor CPU performance

We have two identical servers with the following specs: 4 sockets containing AMD Opteron 6172 at 2.10 GHz each of which have 12 cores 64 GB RAM One runs Windows Server 2008 R2 Standard, which ...
0
votes
3answers
1k views

MySQL insert cause high disk i/o wait?

Im getting what appears a lot of wait time when performing large inserts in Mysql. Am I correct in assuming I have a disk I/O problem? Yes I am running Mysql on a VM. Innodb_buffer_pool hit rate is ...
13
votes
4answers
16k views

How to identify I/O bottlenecks on a Linux server?

How do you determine that the performance of your Linux server is I/O bound and, perhaps more importantly, what process or processes are casuing the problem?
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, ...
5
votes
2answers
355 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 ...
0
votes
3answers
291 views

SQL Server Monitoring [closed]

I am looking for some open source software which I can use to monitor Microsoft SQL server 2005 & 2008. The features that I would like include: Graphing Recording of CPU usage Recording of Disk ...
1
vote
1answer
109 views

Does taking EBS snapshots supposed to significantly slow down the performance of the EBS volume?

I'm trying to decide on the frequency of making snapshots. Is the AWS system designed in such a way that taking snapshots has a negligible effect on the performance of the volume, or can it ...
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
47 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?
2
votes
2answers
576 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 ...
-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 ...
1
vote
1answer
76 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 ...
3
votes
0answers
67 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 ...
22
votes
7answers
29k views

How can you know what is w3wp.exe doing? (or how to diagnose a performance problem)

I'm having a performance problem in a site we've made, and I'm not exactly sure how to start diagnosing it. The short description is: We have a very small site (http://hearablog.com) with very little ...
0
votes
1answer
104 views

PCI Extender and 1GB Ethernet Performance

One of my server has 2 PCI slots which has already plugged with 1GB Ethernet cards. I want to add two more 1GB NIC to this server. I've found on ebay this pci extender. I want to ask, because I ...
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 ...