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

learn more… | top users | synonyms (2)

2
votes
1answer
161 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] ...
-1
votes
1answer
134 views

Innodb performs IO Operation when idle

I am currently doing some stress testing where I am pushing inserts to the database as fast as I can. The simulation inserts 10000 records per second. After inserting around 200 million records I ...
4
votes
3answers
1k views

Why do servers have SAS instead of SSDs? [closed]

I was wondering why do servers still come with SAS disks instead of SSD disks? I know that SAS are faster than normal hard drives but they are still much slower than SSDs. I think they are more ...
0
votes
1answer
680 views

SCOM alert: The threshold for the Logical Disk\Avg. Disk sec/Transfer performance counter has been exceeded

We are monitoring several Windows Server 2012 R2 VMs running on Hyper-V. Now SCOM (2012 R2 UR2) reports: The threshold for the Logical Disk\Avg. Disk sec/Transfer performance counter has been ...
0
votes
1answer
27 views

How do I know website slowness is related to network or my server

I do know that my php pages generate in less than 0.1 seconds. And also I do know that apache max clients has not been ran out. And website is slowness is confirmed by testing from different ...
0
votes
0answers
79 views

Nginx : Images takes too long to load. (1sec to download a 50KB image)

I just switched from Apache to debian 7.6 nginx php-fpm and after running all kind of optimisations it seems that it takes a lot longer than usual to display images : The application is extremely ...
-1
votes
1answer
39 views

Child process runs in normal priority only. Why? [closed]

I run a scheduled task in Windows Server 2008 R2. I used the technique described here to set its priority to high priority (level 1 of 7). My task runs a process (an EXE file) that creates child ...
0
votes
1answer
423 views

How to speed up QEMU on Windows host?

We want to run our Ubuntu 64bit web server virtualized/emulated on a Windows 64bit host. Intended use is to distribute the VM to customers who might not have "elevated" or "admin" rights on the ...
0
votes
0answers
49 views

clonehd takes 2 hours for a 100GB disk. Expected?

I have a VirtualBox image using VDI and flexible size. Right now the physical DVI file 94GB. The host is an Ubuntu server and the guest is a CentOS 6.4 with ext4 partition. The host is using a sata ...
0
votes
0answers
115 views

Tunning nginx/php5-fpm : why low memory usage with 800 users?

I did optimize nginx with what I found on the internet My specs are 2 servers load balanced : Intel Xeon E5-1620v2 (4c/8t 3,7 GHz+/3,9 GHz+) 32 Go DDR3 ECC 1600MHz 3x 160Go SSD Intel DC S3500 SATA3 ...
13
votes
4answers
6k views

Why VM snapshots are affecting performance?

I read in one of the VMware KB article says that snapshots will directly proportional to VM performance. But my team keep asking me how snapshots can affect performance. I would like to give them ...
3
votes
2answers
128 views

Performance associated with storing millions of files on NTFS

Does anyone have a method / formula, etc that I could use - hopefully based on both current and projected numbers of files - to project the 'right' length of the split and the number of nested ...
5
votes
4answers
7k views

How can I find out what is causing interrupts on Windows?

Occasionally I come across servers (Windows 2003 and 2008) with high processor % interrupt time. Is there a way to see what program or device is causing the interrupts?
6
votes
0answers
61 views

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

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 ...
5
votes
1answer
238 views

How to distribute files and folders to handle large number of files

I want to manage a huge number of files on my server (say millions). It is needed to save files in two or three levels of folders to keep the number of files in each folder low. On the other hand, it ...
-1
votes
2answers
223 views

High CPU usage on Linux machine

I have a piece of java code running on two different machines, but on one of the linux machines, the code uses a lot of CPU (close to 100% cpu usage). On the other machine the same code uses less cpu ...
1
vote
6answers
4k views

MySQL performance over a (local) network much slower than I would expect

MySQL queries in my production environment are taking much longer than I would expect them too. The site in question is a fairly large Drupal site, with many modules installed. The webserver (Nginx) ...
3
votes
1answer
431 views

Quantifying the effects of partition mis-alignment

I'm experiencing some significant performance issues on an NFS server. I've been reading up a bit on partition alignment, and I think I have my partitions mis-aligned. I can't find anything that ...
0
votes
2answers
2k views

Is it possible to use SSD for storage on Windows Azure?

There is some marketing-speak suggesting that it may be possible ..: http://gigaom.com/2012/06/05/new-windows-azure-goes-all-ssd-to-one-up-amazon-in-the-cloud/ .. but I couldn't find any way to ...
7
votes
5answers
5k views

Freebsd or Linux? as BGP router over 100mbps

I am building a server to act as a BGP border router for my 100mbps uplink in ISP. I needs these feature: 1) Dual stack BGP peering/routing (at least 100Mbps, maybe more). 2) Potential full internet ...
3
votes
1answer
142 views

Why would zfs performance be bad for moving files within an fs?

On my FreeNAS NAS (9.1.1 running zfs v28), I am getting terrible performance for file moves between two directories in the same raidz fs. Is this expected? How can I fault-find this, if not? The ...
63
votes
13answers
13k views

Are networks now faster than disks?

This is a software design question I used to work on the following rule for speed cache memory > memory > disk > network With each step being 5-10 times the previous step (e.g. cache ...
6
votes
9answers
6k views

How do I benchmark performance of external DNS lookups?

I'm considering Google's public DNS servers as the external DNS for my network. Currently I'm using the DNS servers from my ISP. I've also considered OpenDNS in the past, but ultimately decided not ...
0
votes
2answers
231 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, ...
-1
votes
1answer
72 views

Google Compute Engine VM performance issue [closed]

we have deployed our portal on Google Compute Engine's VM instance. This is a 2 CPU 13 GB Ram with Debian OS. The link to the deployed site is http://www.beawel.com/UGC (Cloud VM). Our testing server ...
0
votes
0answers
295 views

When I should ignore apr_socket_recv: Connection reset by peer (104) in ab test?

I encountered the well-known apr_socket_recv: Connection reset by peer (104) error during my ab test against my server. But I noticed there is a '-r' option in ab which means Don't exit on ...
2
votes
2answers
3k views

Testing SSL performance on Nginx

I'm running nginx 1.0.0 on CentOS 6 x86_64 with stock OpenSSL. Below are results of openssl benchmarking. sh# openssl speed aes-256-cbc OpenSSL 1.0.0-fips 29 Mar 2010 built on: Sat Jun 25 04:58:15 ...
0
votes
0answers
340 views

XenServer 6.2 Read Only and Slow Disk I/O

I virtualized a datacenter a few months back and we have a pool of 3 HP DL360 G5 servers, each with 32GB of Memory and dual Intel Xeons. Recently we have been experiencing 2 issues, the first of which ...
0
votes
0answers
33 views

does the number of lvm logical volumes affect ssd performance

Please let me know what your thought are on this. I've installed Ubuntu multiple times on a msata ssd mS200S3 120GB. There is a noticeable decrease of read performance on the exact same hardware for ...
0
votes
0answers
12 views

How to monitor and alert on a program's resource usage Server 2008?

We have a program that at various times utilizes very high CPU and memory. I would like to create a collection of performance logs of this particular application to see a historical trend over time ...
1
vote
0answers
170 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
291 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. ...
2
votes
3answers
649 views

sudden peak in cpu usage

We are running a 4 node/machine elastic search cluster on 12 core, 96gb RAM, 4 spinning disk machines. under normal operation most cpu usage is user and around 5-10%. Every few days, one of the ...
6
votes
6answers
2k views

Windows 2008 Server on mixed ethernet speeds — download from share slow, but fast plain TCP

I have a Windows Server 2008 R2 x64 server that is AD controller and file server. I have a problem that Windows XP clients experience terribly slow (less than 10Mbps, really less than ...
1
vote
0answers
65 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
4answers
4k views

Drawbacks of installing linux on usb stick?

I am setting up a router/nas/http/whatever server based on an ION mini-ITX board. I've installed Ubuntu Server on an old 160 GB drive, but it generates a lot more heat and vibrates more than my other ...
3
votes
1answer
266 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 ...
-1
votes
2answers
40 views

How to meassure disk access [closed]

How can I meassure the disk access on Windows Server 2012? We have some storages attached via iSCI one with SSD and the other not. I would like to compare the disk access speed. In order to figure out ...
5
votes
4answers
10k views

Howto check disk I/O utilisation per process

Im having a problem with a stalling Linux system and I have found sysstat/sar to report huge peaks in disk I/O utilization, average service time as well as average wait time at the time of the system ...
-2
votes
1answer
225 views

Why does a low level format take very long time?

I can write ~100MB/s on a particular 4TB SAS drive when it have a file system on it, but a low level format on this drive took >16 hours. That's ~70kB/s. Since there is not filesystem and only zeroes ...
1
vote
1answer
71 views

Poor performance executing “cp -al” over a NFS export

I am in the process of implementing a backup of a WD My Book Live Duo. This device is configured with software RAID0. The backup source directory is the root of the device, and the destination is a ...
0
votes
0answers
38 views

Why is my server so slow to accept connections?

I've noticed that my server seems to be very slow to accept connections - i.e. when analyzing the load time using the Chrome event map, it shows that some tasks can spend multiple seconds waiting for ...
2
votes
2answers
92 views

Lots of major page faults in CentOS

We have a fairly complicated PHP script that's generating a lot of minor and major page faults. $> ps -o min_flt,maj_flt,time,cmd,pid 4686 MINFL MAJFL TIME CMD ...
0
votes
2answers
165 views

Debugging slow transfer rate from server [duplicate]

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 ...
1
vote
1answer
75 views

MySQL suddenly taking 2000 ms per request, instead of 200

UPDATE: finally remembered to look at munin, and it seems that one of the HDDs is the root of the problem after all, unless I'm totally reading this wrong. Here's the munin output: ...
-1
votes
1answer
42 views

HDD performance testing over LAN [closed]

Do you know some utility that allow me for HDD performance testing over lan. The issue - I have a shared drive with shared file database. Performance of the database is low and I assume that ...
1
vote
1answer
193 views

How can I diagnose and speed up slow Linux puppet sync?

I'm running puppet and it functions okay, but it's taking about 15 minutes on a sync without any changes, and it seems to me that this shouldn't take more than a minute or two. Here are some stats: ...
1
vote
1answer
139 views

MongoDB - DB/collection fragmentation level

I recently had a performance issue with one of my collections. On a whim (and thanks to this article), I decided to try compacting (as written in the official documentation). This worked brilliantly. ...
0
votes
1answer
58 views

Is there anyway to find what php scripts consume more resources

I want to easily find load cause, Is there a way to display resource usage for php scripts like this. Cpu: index.php 30% something.php 10% ... memory: index.php 50% something.php 10% ..
0
votes
2answers
124 views

Unreasonable performance expectations for RAID 0 performance?

This is my first time building a machine with a hardware RAID card. We bought a Dell T620 with the H710P RAID controller (1GB NV Cache), a 160GB Solid State Drive (SATA Read Intensive MLC 3Gbps), and ...