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

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5
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0answers
43 views

Fast distributed filesystem for a large amounts of data with metadata in database

My project uses several processing machines and one storage machine. Currently storage organized with a MSSQL filetable shared folder. Every file in storage have some metadata in database. Processing ...
3
votes
0answers
1k views

Use perfmon to monitor a specific ASP.NET webapp across worker process restarts, IIS restarts, etc.?

I have a few perfmon performance counters that I'd like to track for a specific ASP.NET application over an extended period of time, say a week or a month. The trouble is that perfmon counters are ...
2
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0answers
51 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
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0answers
523 views

Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
2
votes
0answers
75 views

How to debug sluggish process performance

I have a test application which writes a string to a file 10000 times. I run this on two servers and I get totally different results. [SYSTEM 1] $ time ./test_depth real 0m0.152s user ...
2
votes
0answers
126 views

mdadm raid10 or nfs performance issues?

I have a fresh mdadm RAID10 device which is healthy, built from 4 x 7200rpm SATA 3 drives: # cat /proc/mdstat Personalities : [raid10] [raid1] md2 : active raid10 sdc3[5] sda3[4] sdb3[1] sdd3[3] ...
2
votes
0answers
80 views

Infiniband link is at 4X SDR with DDR HCAs; has anyone seen this before?

I've recently upgraded my Infiniband HCAs from SDR to DDR, however upon upgrading, it has not improved the link speed at all. Receiving the following output from 'iblinkinfo': CA: ip-san-1-au3a ...
2
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0answers
69 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 ...
2
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0answers
53 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 ...
2
votes
0answers
57 views

Item count limit in Public Folders?

I'm in the planning phase for a product that is based around an Exchange 2010 (SP2) server, where our items will be stored in public folders. There could be hundreds of thousands of items, and I want ...
2
votes
0answers
166 views

High %soft CPU usage during high network load on ixgbe

We have an Intel 82598EB 10GBE NIC. The network load is composed of lot of small sized UDP packets. To simulate a DDoS, from another server we pushed ~100k pps small UDP packet (just some Mbit of ...
2
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0answers
216 views

Slow Transfer Speeds from KVM host to client

I am trying to isolate the root cause of slow transfer speeds from my host OS to a KVM client. Both are Ubuntu 12.04 LTS Linux. Rsync on the host 192.168.1.72 rsync -auv --progress rut3.img /tmp/ ...
2
votes
0answers
433 views

Troubleshooting Redmine performance

I've got a Redmine instance (Bitnami Stack) that's unusually slow. Because I'm just trying to get to the bottom of this, I have some theories which I'd like to discuss here. So, if anybody has any ...
2
votes
0answers
130 views

Full Text Search query elapsed time varying wildly

Database Version: Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86) Nov 24 2008 13:01:59 Copyright (c) 1988-2005 Microsoft Corporation Express Edition with Advanced Services on Windows NT 5.1 ...
2
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0answers
77 views

Benchmarking a file server

I'm working on building a new file server... a simple Windows Server box with a few terabytes of disk space to share on the LAN. Pain for current hard drive prices aside :( -- I would like to get ...
2
votes
0answers
395 views

MySQL INSERT … SELECT renders server unresponsive

Solution: Although I haven't found a proper solution yet I'm at least sure that this is purely a disk I/O problem and has nothing to do with MySQL... I have a MySQL server (5.1.54-1ubuntu4-log) ...
2
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0answers
64 views

Text entry out of order during slowness Windows Server 2003 terminal server

When the server is running slowly, anything I type in any text entry box comes in out of order. For example, IPCONFIG might become IPFIGCON. Basically, our Windows Server 2003 R2 x64 Terminal Server ...
2
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0answers
646 views

ejabberd benchmarks and performance

I'm considering to use XMPP for messaging platform (not a chat, I'd rather use it as a transport protocol) for communicating one to one, one to many between custom clients and I think I will ...
2
votes
0answers
972 views

How can I improve performance over SMB/CIFS for an application that has poor write speeds?

I have a third party application that reads several large files and generates a third large file. Its performance is quite good when the generated file is stored on "local storage", i.e. either a ...
1
vote
0answers
33 views

Network Performance / SMB-CIFS / Guidance

I'm an IT professional working out of my home office. I'm having some performance problems (NAS file copies) which I'm trying to isolate, using iperf. My question is on iperf. Infrastructure - ...
1
vote
0answers
51 views

Sizing of journal disks with Microsoft Storage Spaces parity volume

I'm currently speccing out a new backup server. It's going to be running Windows Server 2012 R2 with Direct Attached Storage, and I'm considering using Storage Spaces rather than using a RAID card. ...
1
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0answers
33 views

slow copy due to disk write issue

I am trying to copy a file from /backup/ folder to /backup/abc/ and it is taking a lot of time. The copy operation on performed on other server is pretty fast. # df -HP Filesystem Size Used ...
1
vote
0answers
23 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
0answers
44 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; ...
1
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0answers
186 views

apache performance static file

I have a fairly low-budget VPS (1GB RAM + 2 CPU's) to run a few (5 - 10) different small websites (both static and dynamic). These websites have (very) low traffic (average of 500 unique visits for ...
1
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0answers
33 views

Frequent CPU spikes on fresh install

I just reinstalled my Server (Windows Server 2008 R2) and after installing MySQL 5.6, the CPU spikes every few seconds: http://s15.postimg.org/dno7ztfjf/cpuspikes.png Even worse than the higher CPU ...
1
vote
0answers
135 views

SSD+MDRAID+LVM+KVM results in lower performance than expected

We use kvm for virtualization, the disk images are stored as logical volumes. The logical volumes are stored on a bunch of software-RAID1 (mdadm) arrays composed of Intel DCS3500 SSDs (each array is a ...
1
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0answers
99 views

Postfix performance and how to increase my throughput?

What I've read so far: Postfix Tunning Postfix Bottle Neck Analisys The Book of Postfix (chapter 22) I have similar specs to this guy but I'm only able to send about ~1300 emails/hour What I've ...
1
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0answers
33 views

How do I reduce server load for a dormant WordPress site using W3 Total Cache?

My current host who did all performance optimization for me has jacked up their price to $1,000/month, so I was forced to move to a new host. The new host charges only $150/month. They give you W3 ...
1
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0answers
140 views

Why are pgpgin/s and majflt/s inconsistent in sar -B?

In sar -B ouptut, I would naively expect pgpgin/s to equal majflt/s multiplied by the system page size. From man sar: pgpgin/s Total number of kilobytes the system paged in ...
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0answers
149 views

Apache AB results: why does adding concurrency not increase requests processed per second?

So I've been trying to use apache ab to benchmark performance, but I'm having trouble understanding why I'm getting these results. FYI, its a PHP app using Zend Framework, mySQL database, and mostly ...
1
vote
0answers
297 views

windows2012 failover cluster + storage. Considerations

We plan to build a failover storage with Windows2012r2. There will be 2 or 3 physical machines with 2 virtual machines on each server. One virtual machine building a failover, second one being storage ...
1
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0answers
137 views

Reason for high CPU time when executing fio

After weeks of troubleshooting some performance issues I have on my VPS running Ubuntu 12.04 LTS, I am getting closer to the conclusion that the problem is related to IO. When I have a considerable ...
1
vote
0answers
119 views

best setup for fast sustained streaming (sequential?) disk writes

i am setting up a high speed/high resolution scientific image acquisition system. i need data write rates of ~1 GB/sec sustained for ~1 hour. i don't have experience with raid, but my plan is to ...
1
vote
0answers
126 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 ...
1
vote
0answers
24 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 ...
1
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0answers
100 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 ...
1
vote
0answers
380 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 ...
1
vote
0answers
23 views

Performance difference between multiple people requesting one file VS multiple identical files in different paths

Suppose I have X amount of users requesting http://mydomain.com/myfile.php Now consider a different scenario where the same X amount of users are requesting myfile.php, except instead of being ...
1
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0answers
82 views

File I/O Throughput

I have an IBM x3650 M4 server (64-bit) running Ubuntu 13.04 Desktop (32-bit). I realize that this is a non-standard setup by it's being driven by other requirements. I am seeing slow file writes ...
1
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0answers
106 views

IIS 7 configuration does not lead to expected performances/thread count

I have a Windows Server 2008 R2 server running some web services through IIS 7. The web services run in integration mode with .NET Framework 2.0. The web services communicate with each other and with ...
1
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0answers
120 views

Stunnel + Varnish + Apache questions

I am currently running Varnish in front of apache for all http traffic. I added stunnel so as to take advantage of the cache for https connections as well. So, for https, stunnel talks to varnish ...
1
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0answers
63 views

Is there any gain in removing old unused Handler Mappings in IIS 7?

I want to clean up my live server after removing a Classic ASP subset from a live web application. Other than cleaning up configuration, is there any other gains from disabling unused mappings in ...
1
vote
0answers
186 views

Postfix, Attachments and Virus scanning, difference between Milters AND Filters? Efficiency and Performance

I'm re-implementing an overloaded Postfix cluster, which beyond its many problems, has major efficiency concerns. The cluster is a dedicated MX Gateway, so mailboxes are not a consideration. ...
1
vote
0answers
47 views

Sluggish Sharepoint Application

I have Sharepoint 2010 application on a VM with 4GB RAM. There is no search crawl schedule setup on it. it runs smoothly during certain times of day however, whenever it feels like: the CPU usage hits ...
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vote
0answers
97 views

iptable DNAT poor performance

I have the following rule for PORT FORWARDING: root@foo:~# iptables -t nat -S -P PREROUTING ACCEPT -P INPUT ACCEPT -P OUTPUT ACCEPT -P POSTROUTING ACCEPT -A PREROUTING -p udp -m udp --dport 1:1024 ...
1
vote
0answers
62 views

% segments retransmitted above threshold

I've been doing some monitoring on our servers and we get warnings that the TCPv4 / % Segments Retransmitted is above acceptable threshold: http://imgur.com/b8RNm Is there any way to tell what the ...
1
vote
0answers
46 views

Chrooted from LiveCD: Bad IO performace

my Ubuntu Server installation is broken, so I grabbed a Ubuntu Desktop CD, mounted my Ubuntu installtion on my hard disk and chrooted into it. But now my IO performance is really bad: # time dd ...
1
vote
0answers
148 views

Apache serving Samba share leads to poor performance?

This is a question about a problematic interaction between Apache and Samba. Our Linux server (on a private intranet) mounts a Windows share, which is physically thousands of miles away, and serves ...
1
vote
0answers
85 views

Getting the virtual memory address for (major) page faults

On a Linux (Cent OS 5) system, I have a process that accesses a large amount of memory mapped files. The process is generating a large amount of page faults because the aggregated size of the mapped ...