30 agosto 2013

"Introducing Windows Server 2012 R2" free ebook

Download it from this link:  http://aka.ms/IntroWinServ2012R2Preview/PDFebook

29 agosto 2013

How to test network performance with Netperf

As we can read at the offcial webpage: "Netperf is a benchmark that can be used to measure the performance of many different types of networking. It provides tests for both unidirecitonal throughput, and end-to-end latency"

It´s so usefull to test network performance between two virtual machines , for example from a database server to the aplicacion client.

First, download Netperf for Linux or Windows O.S and install or unzip it:

    Linux:  http://www.netperf.org/netperf/DownloadNetperf.html

    Windows: https://i18n-zh.googlecode.com/files/NetPerf-2.4.5-w32.zip

See a Windows example:

-Start server side. You can specified a port with -p

-Start client side. With -h you can see all the options.

In this case, we get a test with the result 524,55 Mbit/s (Mbps) between two virtual machines.

The simple test run for 10seconds, but this can be changed to. Netperf -h:

E:\datos\NetPerf-2.4.5-w32>netperf -h

Usage: netperf [global options] -- [test options]

Global options:
    -a send,recv      Set the local send,recv buffer alignment
    -A send,recv      Set the remote send,recv buffer alignment
    -B brandstr       Specify a string to be emitted with brief output
    -c [cpu_rate]     Report local CPU usage
    -C [cpu_rate]     Report remote CPU usage
    -d                Increase debugging output
    -D [secs,units] * Display interim results at least every secs seconds
                      using units as the initial guess for units per second
    -f G|M|K|g|m|k    Set the output units
    -F fill_file      Pre-fill buffers with data from fill_file
    -h                Display this text
    -H name|ip,fam *  Specify the target machine and/or local ip and family
    -i max,min        Specify the max and min number of iterations (15,1)
    -I lvl[,intvl]    Specify confidence level (95 or 99) (99)
                      and confidence interval in percentage (10)
    -l testlen        Specify test duration (>0 secs) (<0 bytes="" font="" trans="">
    -L name|ip,fam *  Specify the local ip|name and address family
    -o send,recv      Set the local send,recv buffer offsets
    -O send,recv      Set the remote send,recv buffer offset
    -n numcpu         Set the number of processors for CPU util
    -N                Establish no control connection, do 'send' side only
    -p port,lport*    Specify netserver port number and/or local port
    -P 0|1            Don't/Do display test headers
    -r                Allow confidence to be hit on result only
    -t testname       Specify test to perform
    -T lcpu,rcpu      Request netperf/netserver be bound to local/remote cpu
    -v verbosity      Specify the verbosity level
    -W send,recv      Set the number of send,recv buffers
    -v level          Set the verbosity level (default 1, min 0)
    -V                Display the netperf version and exit

For those options taking two parms, at least one must be specified;
specifying one value without a comma will set both parms to that
value, specifying a value with a leading comma will set just the second
parm, a value with a trailing comma will set just the first. To set
each parm to unique values, specify both and separate them with a
* For these options taking two parms, specifying one value with no comma
will only set the first parms and will leave the second at the default
value. To set the second value it must be preceded with a comma or be a
comma-separated pair. This is to retain previous netperf behaviour.

Take care with the units (about caudal, no about velocity):

106 bit = 1 000 000 bit/s = 1 Mbit/s

1 megabyte/s = 8 megabit/s

1 megabit/s = 1000 kilobit/s = 125 kilobyte/s

UnitBitsBits / 1,000,000

26 agosto 2013

What’s New in VMware vSphere 5.5

La nueva version de vSphere 5.5 y de ESXi 5.5 duplica algunos de los
maximos de la version 5.1.
De especial interes los maximos del appliance de vCenter que ahora permite 500 host ESXi y 5000 virtual machines; mayor compatibilidad para los MSCS, discos VMDK y RDM de hasta 62 TB woooow!

El resumen de las mejoras:

Hot-pluggable SSDPCIe devices
Supportfor Reliable Memory Technology
Enhancements to CPUC-states
Virtual machine compatibility withVMware ESXi 5.5
Expanded supportfor hardware-accelerated graphics vendor
Graphic acceleration supportfor Linux guest operating systems
vCenter Single Sign-On Server security enhancements
vSphere Web Client platform support andUI improvements
vCenter ServerAppliance configuration maximum increases
Simplified vSphereAppHAapplication monitoring
vSphereDRS virtual machine–virtual machine affinity rule enhancements
vSphere BigData Extensions, a new feature that deploys and managesHadoop clusters on vSphere    
from within vCenter vSphere 5.5 also includes the following storage-related enhancements:
Supportfor 62TBVMDK
MSCS updates
vSphere 5.1 enhancements
16GB E2E support
vSphere Replication interoperability and multi-point-in-time snapshotretention
vSphere 5.5 also introduces the following networking-related enhancements:
Improved LACP capabilities
Traffic filtering
Quality of Service tagging

Mas info en el doc oficial:

16 agosto 2013

Como funcionan realmente las Snapshost de VMware

Muchos administradores de VMware no conocen "realmente" como funcionan las snapshots de Vmware y confunden conceptos sobre los puntos de restauracion, los vmdk que se crean al lanzar la snap, el significado de "borrar" o "consolidar" las snapshots...etc.

Este video del VMware explica de modo muy sencillo todo esto: