Switch 10g-40g buying guide

here :
on arpaware
linkedin article

TCO open switch - Cumulus Network

Here:
The Facts Behind the Myth

Hyperconvergence vs SAN

here:
Hyperconvergence vs SAN: A Comparative Analysis

Future of sun sparc and sun solaris

After oracle acquisition of sun, the development of sun sparc processor also sun solaris operating system until now need time to make more better progress.

These two articles simply explain:

http://www.networkworld.com/article/3160176/hardware/game-over-for-solaris-and-sparc.html

https://www.theregister.co.uk/2017/01/18/solaris_12_disappears_from_oracles_roadmap/

Eliminating toil

Toil is not just "work I don’t like to do." It’s also not simply equivalent to administrative chores or grungy work. Preferences as to what types of work are satisfying and enjoyable vary from person to person, and some people even enjoy manual, repetitive work. There are also administrative chores that have to get done, but should not be categorized as toil: this is overhead. Overhead is often work not directly tied to running a production service, and includes tasks like team meetings, setting and grading goals,19 snippets,20 and HR paperwork. Grungy work can sometimes have long-term value, and in that case, it’s not toil, either. Cleaning up the entire alerting configuration for your service and removing clutter may be grungy, but it’s not toil.

So what is toil? Toil is the kind of work tied to running a production service that tends to be manual, repetitive, automatable, tactical, devoid of enduring value, and that scales linearly as a service grows. Not every task deemed toil has all these attributes, but the more closely work matches one or more of the following descriptions, the more likely it is to be toil: Manual, Repetitive, Automatable, Tactical, No enduring value, O(n) with service growth

references:
https://landing.google.com/sre/book/chapters/eliminating-toil.html
https://medium.com/production-ready/toil-a-word-every-engineer-should-know-f0b676e41c86

Limiting bandwidth usage on linux centos

Sometimes want to limit the use of bandwidth by the server, so that other servers also get enough bandwidth.
There are several ways, but the quick way to use wondershaper :
terkadang ingin membatasi penggunaan bandwith oleh server, agar server lairikut :

#yum install wondershaper -y

#wondershaper eth0  128 128  ( for 128 kbps in and 128 out )


tested in : CentOS release 6.8

Check patch / update level on solaris


to find what update level from o/s solaris are installed as follows:


# cat /etc/release
                   Oracle Solaris 10 8/11 s10s_u10wos_17b SPARC
  Copyright (c) 1983, 2011, Oracle and/or its affiliates. All rights reserved.
                        Assembled 23 August 2011



s10s_u10wos_17b the u<#> is the update version. So that is Solaris 10 Update 10

reference :

https://serverfault.com/questions/524883/what-part-of-solaris-version-string-ids-the-update

How to find oracle weblogic Version

When performing a problem analysis on the weblogic server one of the required is to look at its weblogic version. Here's how to check the weblogic version installed on the server:

1. From registry.xml in MW_HOME

Go to the home directory of the weblogic user:


  # find ./ -name registry.xml


  # more ./Oracle/Middleware/registry.xml | Grep version


A line appears like this:

Name = "WebLogic Server" "version =" 10.3.3.0 "(variable version next to this will tell you weblogic version)

2. From WebLogic Admin Server logfile at $ DOMAIN_HOME / servers / AdminServer / admin / AdminServer.log and search for "WebLogic Server".


  #cd / home / weblogic /


  #grep "WebLogic Server" ./nameofDomain/servers/AdminServer/logs/AdminServer.log | More


Tested in CentOS release 6.5

Reference:
http://onlineappsdba.com/index.php/2011/04/28/how-to-find-oracle-weblogic-server-version/

Flush or Clear ram memory or buffer memory in linux Centos

Sometimes the use of applications on the linux server is very high, either because of high server load or anything else caused by the application. 
But to be able to restart the operating system is not possible or many things to consider such as downtime or coordination with other parties.

Here's how to make the linux server memory free again:

1. Clear PageCache only
#sync; echo 1 > /proc/sys/vm/drop_caches

Clear dentries and inodes.
#sync; echo 2 > /proc/sys/vm/drop_caches

3. Clear PageCache, dentries and inodes.
#sync; echo 3 > /proc/sys/vm/drop_caches

Tested on CentOS release 6.7

References: 
https://tecadmin.net/flush-memory-cache-on-linux-server/
https://www.tecmint.com/clear-ram-memory-cache-buffer-and-swap-space-on-linux/ 
https://unix.stackexchange.com/questions/87908/how-do-you-empty-the-buffers-and-cache-on-a-linux-system