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

learn more… | top users | synonyms (2)

8
votes
5answers
23k views

Does the DisablePagingExecutive registry change have any actual effect?

On a number of machines in the past, across different versions of Windows (2000, XP, and no Vista), I've enabled DisablePagingExecutive to try and improve performance. In each case, and I've had ...
2
votes
0answers
24 views

Calculation of Xeon server memory bandwidth

I am looking at a dual socket server based on the Intel(R) Xeon(R) CPU E5-2640 v3 @ 2.60GHz The configuration looks like this. 4 memory channels per socket DIMMs are 8x32 GB DDR4 2133/1866 modules ...
29
votes
6answers
83k views

High load average, low CPU usage - why?

We're seeing huge performance problems on a web application and we're trying to find the bottleneck. I am not a sysadmin so there is some stuff I don't quite get. Some basic investigation shows the ...
0
votes
0answers
7 views

Recommended Hardware for a school lab LTSP [duplicate]

currently I'm working on a project for a elementary school's computer room/lab. They have a lot of old computers (AMD Athlon CPU f.e.) with WinXP. The teachers are afraid of using that insecure ...
-1
votes
0answers
27 views

Why database performance decrease in different data centers? [on hold]

I'm trying to migrate all our infrastructure to the cloud. In order to do that, we need to ensure that our application performance would, at least, be the same. So we set 2 environment with our ...
1
vote
2answers
1k views

Ubuntu Server 14.04LTS Swappiness for server with 16GB memory

(don't worry I'm not asking what my setting should be, asking for the theory behind some conflicting advice I've read) My application is one that is lightweight and not under much load, but needs to ...
0
votes
1answer
43 views

Does the Dell backplane affect the speed of the drives?

I've already checked the following questions but couldn't find an answer: Does the backplane on an HP server have any impact on the speed of the drives? 3rd party SSD drive in HP Proliant server only ...
0
votes
0answers
15 views

How to check that VMWare virtual machine is receiving sufficient resources from the physical server?

We have VMWare virtual machine in data center but applications on it suddenly started to be slow after one weekend. We are considering possibility that data center has moved virtual machine to other ...
0
votes
0answers
8 views

Sar command “sar -n EDEV -f /var/log/sa/sa16 -s 11:00:00 -e 15:00:00”

sar -n EDEV -f /var/log/sa/sa16 -s 11:00:00 -e 15:00:00 I am using above command on Red Hat Enterprise Linux Server release 5.9, and below is the output to that:(Dev error form 11 am to 3 pm). I have ...
0
votes
1answer
2k 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 ...
3
votes
2answers
1k views

Files served from Apache are slower than other methods

I have a vps with a 1Gb/s line, when running apps on the server I can get (be it not full) reasonable speeds, but when downloading files through apache from this server I never reach close to my line ...
1
vote
1answer
2k views

interpreting IOPS these Bonnie++ and iostat results

I am looking to interpret the IOPS from a few runs of bonnie++ using iostat simultaneously and using the benchmarking from this post: Can I determine IOPS on a disk array using bonnie++? bonnie++ ...
-1
votes
0answers
15 views

Optimizing Backup Server for Transfer Speed

We’ve built a backup server with both internal and external arrays for hosting our SQL and file server backups. The internal array is humming along but the external array is 10x slower to back up the ...
8
votes
6answers
5k views

How to identify heavy write to disk?

I have this problem with server running CakePHP application. The server is insanely slow, I first thought that it's application problem, but then I found constant 5-6MB/s write to disk. What is the ...
1
vote
0answers
49 views

Poor performance with docker internal DNS

I have a problem with docker internal DNS. On one of docker container dns server is so slow that it time out most of the queries. Docker is installed in KVM virtual machine and I have several ...
0
votes
1answer
29 views

Performance comparison of single RAID vs multiple filesystems

I'm trying to get maximum sequential disk throughput for an application on my Linux server. It has 7 SATA disks that I could put in one RAID0 or RAID5 using a hardware RAID controller (HP P420i). Or, ...
0
votes
2answers
60 views

Confused about Azure Storage Performance

In my experience so far with Azure the biggest bottleneck seems to be Storage performance. I did a few tests with Crystal Disk Mark and as you can see below the performance is very poor. Especially ...
12
votes
4answers
8k views

LVM Performance overhead?

I would be thankfull if someone who understands how LVM works, could tell me a rough estimate, how much slower using LVM (with a Software RAID1) will be. (What I do not want to know how much slower ...
0
votes
0answers
15 views

How can I launch graph500 benchmark on nVidia GPU with CUDA?

How can I launch graph500 benchmark on nVidia GPU with CUDA? There is written: https://devblogs.nvidia.com/parallelforall/gpus-graph-predictive-analytics/ At the IEEE Bigdata conference later in ...
0
votes
2answers
318 views

MAXDOP and Interesting Performance Experiences

i would like to receive an advice on the following topic. With one of our products from our company we "connect" to an existing database on customers side and import orders into our own SQL Server to ...
3
votes
3answers
1k views

It is possible move a specific file to the beginning of the disk?

It is possible move a specific file to the beginning of the disk? I want to move my virtual machine disk files (virtual disk) to the beginning of the disk to improve disk access performance. I believe ...
3
votes
5answers
618 views

Router limits network performance but its CPU load isn't 100%

I'm using a PC Engines APU device running FreeBSD as a NAT router. The setup is very usual: one WAN connection and one LAN connection. Theoretically, WAN connection is 800/40 Mbit/s and the LAN one ...
2
votes
1answer
59 views

MySQL performance problems after hardware upgrade and move to VM

Recently we've ran some (security) updates on our servers and rebooted the machines. Our development server did not came online anymore due to a problem with the GPU (integrated in CPU). We've ...
0
votes
0answers
8 views

What resources spent symlinks? [duplicate]

I'm working on a web application that makes use of symbolic links. It is a SaaS application where for each user generates symlinks of a core folder and serve them on a new hostname selected by the ...
0
votes
0answers
12 views

/proc/diskstats: No such file or directory

Trying to get some disk performance metrics (in particular, using munin), found that /proc/diskstats does not exist. Tried yum provides '*/diskstats' but nothing except munin was found. CentOS ...
0
votes
3answers
4k views

Squid proxy performing extremely slow and sometimes doesn't work at all

I recently installed Squid on my desktop machine for testing purposes. I didn't edit the config whatsoever, and just pointed firefox at the proxy to see if it was working. Pages take an insanely long ...
1
vote
1answer
59 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
vote
1answer
36 views

How to compare mainframe CPU performance?

I am working with an application that runs on tomcat in OMVS. It run terribly on one mainframe, and great another another. Is there a way I can compare the CPU of the two mainframes as a reference? ...
24
votes
5answers
20k views

Process runs slower as a scheduled task than it does interactively

I have a scheduled task which is very CPU- and IO-intensive, and takes about four hours to run (building source code, if you're curious). The task is a Powershell script which spawns various sub-...
0
votes
0answers
30 views

small client-server app & db install location

We're running Server 2008 R2 on dual 2.8 GHz processors with 32 GB memory and a partitioned 1 TB, 3-disc RAID. Seems plenty robust for our purposes. Our primary application, however, has been lagging ...
1
vote
0answers
23 views

Extremelly slow SMB download, normal SMB upload over LAN

I've been having an issue with a Windows 10 client experiencing very slow download speeds over SMB, but normal upload speeds. I'm able to demonstrate this using LAN Speed Test with the following ...
0
votes
1answer
91 views

High CPU Load on Synology by smbd

I have a Synology DS213j which I access through a VPN via the build-in VPN Server (I use OpenVPN) using Windows Explorer. Copying files to my local hard drive is very slow in the range of only ~170 ...
1
vote
1answer
25 views

Is there a way to configure sudo to not need to lookup group names / or speed up sssd group name resolution?

I've got a large number of Linux hosts that are connected using sssd to a windows active directory domain for user/group lookup. That mostly works fine except for one problem; sudo From what I'...
1
vote
2answers
1k views

Oracle: TRUNCATE sometimes takes ages

Usually, truncating a table takes 5-10 seconds. But when several people work on the same DB instance (but different tables), the operation can take more than an hour. How do I debug this?
11
votes
4answers
1k views

Load time impact of htaccess

There are in general two possibilities of handling stuff on Apache: make configurations for folders one by one using htaccess file to fully resign htaccess and put all the rules into the httpd.conf ...
2
votes
1answer
20 views

Is NUMA always completely NUMA or are there also hybrid systems?

I am working on a high-end server application where performance is critical. Given that servers are often employ NUMA-architectures, the server application also uses NUMA-aware memory allocation ...
1
vote
1answer
1k views

MySQL Extremely High Disk Activity (Read Operations)

I have 1GB Linode VPS with a standard LAMP stack. Apache is tuned fine but for some reason MySQL's disk usage is high. This is causing really slow site load times. RAM and CPU usage are fine. Can ...
0
votes
0answers
28 views

nginx / node server TTFB very high sometimes

I currently have 2 nodes app on a nginx server behind is a mongo db and a elastic search instance. I currently face serious performance issue, this is not related to an overload of number of user, ...
0
votes
0answers
22 views

How do I diagnose an intermittent ADSL issue

A few weeks ago, we started seeing brief intermittent outages of our connection to the internet. Our connection to the internet looks like this: Internet <---> DSL Provider <---> ADSL ...
0
votes
0answers
40 views

How to find which db/collection/query triggers disk read?

We're running a MongoDB 3.0 server with multiple users accessing it and we're experiencing very frequent disk reads by mongod process utilizing our SSD drives to 100% During these peaks the page ...
1
vote
1answer
216 views

Huge performance penalty in gbit link with ip forwarding / masquerade through clear VPN tunnel

I have a problem with IP forwarding between my home computer and a remote server (from online.net). My home connection is a 1 Gbit/s FTTH and the remote server has a 2.5 Gbit/s bandwidth. The context ...
2
votes
2answers
91 views

How can SSD write performance be dramatically different on two identical servers?

I am renting two identical physical servers (at Serverloft). These servers come with 2x512 GB SSD disks, and I've set them up with mdadm in a RAID1. The disks are locally installed in the server. The ...
1
vote
2answers
45 views

How to balance elasticsearch (java) on a very powerful machine?

On a 16 core XEON class, 128GB RAM RHEL server I want to deploy elasticsearch. What is preferable performance-wise? Have a huge elasticsearch process to use all resources on the native host? Break ...
0
votes
0answers
17 views

Gathering Performance Metrics (RAM, CPU, etc) AWS & Azure

We're developing a cross cloud plane performance metric harvester, to collect various performance metrics, but the top 3 being RAM usage, CPU Utilization and Disk Utilization. I know CloudWatch will ...
6
votes
3answers
10k views

Understanding RedHat's recommended tuned profiles

We are going to roll out tuned (and numad) on ~1000 servers, the majority of them being VMware servers either on NetApp or 3Par storage. According to RedHats documentation we should choose the ...
4
votes
0answers
2k 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
votes
0answers
8 views

Move htaccess rules to apache configuration files

I'm running a website with Joomla on a dedicated server (Debian), and i've read that moving .htaccess rules to apache2 configuration files may result in a good performance improvement (Apache HTTP ...
0
votes
0answers
122 views

MongoDB high page faults every 15 minutes, delayed readers

We have a relatively small MongoDB production replicaset. We do about 100 operations per second -- balanced reads and writes. Every 15 minutes or so we see a spike in response time on reads, and in ...
0
votes
0answers
23 views

We are constantly getting CPU Spikes and site slows down [duplicate]

Our website works fine and fast, then out of nowhere cpu spikes to 100% site becomes really slow and after 10 minutes it is back to normal, this is constantly happening. How would one diagnose this? ...