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

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1
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0answers
14 views

Redis parent process smashing disk despite appendfsync = no

We are seeing loads of IO from redis-server despite our save operations being set to occur once every 15 minutes only. The workload is a "full page cache"; we store blobs of compressed HTML. The HTML ...
1
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0answers
24 views

Slow file io performance after large network copy on Win7

In a step of our build process we run a tool that generates about 125,000 files. When generation is complete we copy them up to a network share so other systems can copy them down to process further. ...
3
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4answers
537 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 ...
1
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2answers
111 views

ZFS reads on FreeBSD incredibly slow

I have a FreeBSD 10.0 system on which I have MySQL running with its InnoDB database files stored on ZFS. It seemed to have been going fine for months, but lately, and seemingly suddenly, performance ...
4
votes
1answer
947 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 ...
1
vote
1answer
27 views

Debugging slow server response time [on hold]

I'm testing response time of my VPS server: curl -s -w %{time_total}\\n -o /dev/null http://www.example.com The values are typically round 300ms, Google suggests that it should be lower than 200. ...
0
votes
2answers
854 views

Optimizing disk performance on KVM VM configuration

I have a KVM host server running Ubuntu 12.04 LTS, bare bones installation with only KVM installed. The server has an 8 Core Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GHz CPU with 32GB of RAM and SATA ...
3
votes
1answer
63 views

Linux: Why does the CPU frequency fluctuate when using the performance governor?

I'm using a Debian 8 amd64 machine for benchmarking. During experimentation, I would like the CPU to operate at a fixed frequency (preferably the maximum possible). This will rule out the CPU clock ...
2
votes
1answer
22 views

Can idle NFS mounts on several clients impact performance

We had a NFS server at work which was working with slight lag. However as more mount points were getting created at several clients(serviced by the same server) we noticed the performance coming to a ...
-5
votes
0answers
19 views

Software Developers Learning Path To A System Architect [closed]

I am a system developer with 10 years of development experience my aim is to be a solution architect, typically responsible of 1) designing the enterprise software, seeing through the implementation ...
-2
votes
2answers
50 views

Compare performance of servers [closed]

We have 6 Windows Servers running as VMWare instances on 3 different providers. We a planning to shut down two of them, so my wish is to find out which provider has the worst performance (and ...
4
votes
0answers
18 views

HP MSA P2000 G3 Disk Scrubbing performance?

I have a HP P2000 G3 array with two 10Gbit iSCSI controllers in it that presents storage to my virtualisation cluster. It is soon to be expanded with two D2700 shelves each loaded with 25 10k RPM ...
7
votes
1answer
1k views

ext3 file system performance tuning: what metrics to monitor

I have a high-IO application that is working, and scaling well to date. Over the past few months we've been trying to look down the road and predict where our next bottlenecks will occur. One of ...
0
votes
0answers
26 views

apache 2.2 to 2.4 sporadic performance drop

I updated apache from 2.2 to 2.4 and php from 5.3 to 5.4. For some reason I am experiencing huge performance drops in around 5% of requests to the server. On average, sites load in less than 2 seconds ...
3
votes
3answers
2k views

How can I check if my DB needs more RAM?

How would you check if your postgresql DB instance needs more RAM memory to handle their current working data?
-1
votes
2answers
42 views

how to detect remote switch speed and duplex?

We have a linux (RHEL) system which will be deployed in unknown networks. To support old networks we want to have autoneg configurable. how do you how detect if remote switch is autoneg on|off, and ...
0
votes
0answers
14 views

Conservative Azure Windows VM to Run SQL Server 2008 R2 [duplicate]

For testing purposes I need to set up three Azure Windows VMs to each run an instance of SQL Server 2008 R2 each holding one DB of approx 100GB. There will be quite a few complex stored ...
0
votes
0answers
14 views

Performance monitors

I would need to create a performance monitor on windows server 2012 R2 to monitor the following for a particular period(may be one hour) CPU usage Memory usage Network bandwidth I'm little ...
14
votes
3answers
599 views

NFS poor write performance

I have two machines connected with 10Gbit Ethernet. Let one of them be NFS server and another will be NFs client. Testing network speed over TCP with iperf shows ~9.8 Gbit/s throughput in both ...
2
votes
2answers
58 views

Apache - drawback to high number of httpd processes always running

Is there any issue with having a high number of spare httpd processes always running? I ran a test where I increased StartServers and MinSpareServers by 1,000 and measured the increase in memory ...
0
votes
0answers
17 views

Sudden increase in my CPU usage during random moments(Win Server 2012)

At random times, no matter if I am online or not I see that my server having increased Process usage spikes, as you can see in the picture: So I go inside the Dashboard on the Server Manager, look ...
3
votes
1answer
1k 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 ...
1
vote
1answer
1k views

Unexplicable extreme slowness on Dell PowerEdge R320, fixed only by cold reboot

At this customer's site, there are two new Dell PowerEdge R320 servers with the following configuration: A single 6-core CPU 16 GB of RAM 2x500 GB SATA disks in a RAID 1 array The O.S. is Windows ...
4
votes
1answer
7k views

MySQL high CPU usage on small website

I have a small website hosted on a dedicated server (FreeBSD 9.2, MySQL 5.6.1 and php 5.5.5). The problem is that MySQL eats a lot of cpu resources even if the website have a few visitors. The ...
1
vote
1answer
1k 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
1answer
23 views

Is there a way to determine what impact an upgrade will make other than benchmarking it myself? [closed]

Several posts on capacity planning tells me that the only way for me to determine what hardware I need is to test it myself and benchmark it. Benchmark your code on hardware similar to what you'll ...
1
vote
0answers
39 views

Nginx performance when running multiple instances on the same machine

I'm trying to understand the performance impact of having multiple nginx instances (masters) running on the same machine, rather than having them all load into a single instance using different server ...
1
vote
0answers
31 views

VMWare ESXi and iSCSI via FreeNAS

I've recently been setting up a sandbox ESXi environment with a VM running FreeNAS providing a volume which is connected as a datastore on the host via iSCSI. I've created a VM on this datastore and ...
1
vote
1answer
33 views

RAID1 write penalty using mdadm - what's the cause?

When doing some performance tests writing to a SSD-based 3-way RAID 1 mirror powered by mdadm, it appears we suffer a significant write penalty of about 2.2x slower than doing the same test on just ...
17
votes
4answers
10k views

Why VM snapshots are affecting performance?

I read in one of the VMware KB articles that snapshots will directly affect VM performance. But my team keeps asking me how snapshots can affect performance. I would like to give them solid reason ...
0
votes
1answer
2k views

Why is hash join slow in postgresql 9.1?

I transfered my DB from Postgresql 8.4 to new server with Postgresql 9.1. Size of DB is 9.9GB Data directory is situated on ssd 60GB disk. And server has 16GB RAM and 16 proccessor cores. But today ...
5
votes
2answers
356 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. ...
1
vote
2answers
487 views

Can one root server handle over 50M requests per month? [duplicate]

I am running a LAMP Application installed on one server, happily serving about 1M PI per month. Now I am looking into a potential partnership where my app might serve around 50-80M requests per month. ...
3
votes
2answers
96 views

Performance azure disks, high average queue length

I'm having a classic developer-system admin battle where I am stating that there is an IO problem on the disk of the shared sql server while the system admin tells me that the capacity hasn't been ...
1
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0answers
92 views

100% CPU, load average 0 - how is this possible?

Here's the top output: top - 19:20:47 up 1 day, 4:30, 1 user, load average: 0.01, 0.07, 0.12 Tasks: 170 total, 1 running, 169 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.6 us, 0.9 sy, 0.0 ...
3
votes
1answer
1k views

How to achieve multiple NFS/TCP connections to the same server?

I'm trying to maximize the NFS/TCP bandwidth between a Linux client and a single NFS server over a 10Gbps link. Although each NFS mount has its own device (major/minor), everything comes down to a ...
3
votes
4answers
1k views

How to troubleshoot performance issues of PHP, MySQL and generic I/O

I have a WordPress based website running on a shared hosting. Its response time is very decent (around 2s to retrieve the HTML page and 5s to load all the resources). I was planning to move it to a ...
3
votes
1answer
1k views

CentOS Tuned Equivalent For Debian

Running a few systems, a few are Debian which have been great. I have on the CentOS boxes tuned(tuned-adm) installed and setup for throughput. I searched all over Google and only found some articles ...
1
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2answers
1k views

Horrible PHP/MySQL Query Performance On Ubuntu Server 10.04

I just did a clear install of Ubuntu Server 10.04 with the standard LAMP config.. Then I made a small script to test insert speeds into a table with 3 columns. When I run the script on any of my ...
20
votes
5answers
4k views

Software vs hardware RAID performance and cache usage

I've been reading a lot on RAID controllers/setups and one thing that comes up a lot is how hardware controllers without cache offer the same performance as software RAID. Is this really the case? I ...
1
vote
0answers
13 views

Force disk cache even if guest uses direct i/o

Have IBM db2 on Rhel on Hyper-V on Windows Server. The *.vhdx file is on CSV. e.g. C:\ClusterStorage\volume1\hyper-v\oktest-lb1\oktest-lb1.vhdx. db2 uses O_DIRECT flag (uncached i/o) for its database ...
0
votes
2answers
1k views

Troubleshooting MySQL Performance Issues

Environment: 1 physical machine 8GB RAM some older Core2Duo CPU 1 HDD Windows Vista 64 bit 1 Virtual Machine 16 GB RAM 2 vCPUs Windows 7 64bit Both machines running MySQL 5.5.28 (64Bit) with ...
1
vote
1answer
34 views

Different network speeds from servers on same subnet

I have a pretty strange issue, I'm looking for advice on how I can debug it. I have two servers (A) and (B) on the same subnet and switch. Server A->B transfers at a full 12MB/s and vice-versa. ...
1
vote
0answers
24 views

How to track down bad performance on an api-server

If my api-server shows bad performance, such as high cpu - can this be blamed on the service or on the server? If a regular app-server shows bad performance, all I can do is track down the methods ...
0
votes
0answers
22 views

SSD vs RAM - Optimal ratio for different data sets / databases [duplicate]

I am looking for an advice or even better some studies / benchmarks to read for different scenarios (data sets) when it comes to the best ratio between actual RAM and SSDs. I know that fitting the ...
0
votes
1answer
1k 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
0answers
31 views

vSphere | VMs are balooning and swapping | sched.mem.max paratmetar does not exist

I have two VMs in ESXi5.5 environment that are swapping memory. After a long research I found out the below two articles where it is explained that one must compare the values of memsize and ...
2
votes
2answers
52 views

Migrating Vmware to Hyper-V - number of Virtual CPU

I'm performing a migration from VmWare to Hyper-V and the Virtual CPU that you are assigning to a Virtual Machine is different and I'd like to know what should be the equivalent values when we move a ...
0
votes
0answers
12 views

How can I adjust buffer settings when using xbootmgr?

I am trying to analyze our clients which suffer from long boot & logon delays, so I installed Windows Performance Toolkit. This is the command line I have used to capture a startup: xbootmgr ...
0
votes
0answers
15 views

How to estimate max request per second of web servers? [duplicate]

I'm planning on a system that handles quite a huge amount of requests per second (say 500,000 requests / second). How to estimate maximum request per second of my web server can handle (so that I can ...