Posts Tagged ‘deal’

Start Event Viewer from Command Line (Prompt) – eventvwr.msc to Debug Windows server issues

Friday, November 6th, 2015

eventvwrmsc-event-viewer-windows-7-screenshot-view-windows-log-and-dianose-errors

If you’re a sysadmin which needs to deal with Microsoft Windows servers locally or remotely via Remote Desktop RDP client (MSTSC.EXE) or inside a Windows Domain Controller, you will have to frequently debug Windows isseus or Application caused errors by reviewing debug information stored in Event Logs.

Event Viewer is a precious tool to debug often errors with missing libraries or failing programs on Windows boot and thus on M$ Windows it is the Swiss Army knife of sysadmin.
However as staring Event Viewer using the GUI menus, takes a lot of step and looses you time, e.g., you have to navigate to menus:

1. Start button Picture of the Start button
2. clicking Control Panel
3. clicking System and Security
4. clicking Administrative Tools
5.then double-clicking Event Viewer.‌
6. Granting Administrator permission required If you’re prompted for an administrator password or confirmation

It is much handier to just start it with a shortcut:

Press Windows (Button) + R
– To invoke run prompt

and type:

eventvwr.msc

In case if you’re running eventvwr.msc to connect to remote Windows Server run from command prompt (cmd.exe):

eventvwr-run-from-command-prompt-with-a-smart-shortcut-to-save-time-when-administrating-windows-servers

eventvwr.msc /computer=OTHER_Computer_Name

event-viewer-log-reader-and-debug-tool-for-windows-PC-and-windows-servers-adminsitration

What is Vertical scaling and Horizontal scaling – Vertical and Horizontal hardware / services scaling

Friday, June 13th, 2014

horizontal-vs-vertical-scaling-vertical-and-horizontal-scaling-explained-diagram

If you're coming from a small or middle-sized company to a corporations like HP or IBM probably you will not a clear defined idea on the 2 types (2 dimensions) of system Scaling (Horizontal and Vertical scaling). I know from my pesronal experience that in small companies – all needed is to guarantee a model for as less probels as possible without too much of defining things and with much less planning. Other thing is being a sysadmin in middle-sized companies, often doesn't give you opportunity to discuss issues to solve with other admins but you have to deal as "one man (machine) for all" and thus often to solve office server and services tasks you do some custom solution.
hence for novice system administrators probably it will be probably unclear what is the difference between Horizontal and Vertical Scaling?

horizontal-vertical-scaling-scale-up-and-scale-out-server-infrastructure-diagram

 

Vertical Scaling (scale vertically or scale up) :- adding more resources(CPU/RAM/DISK) to your server (database or application server is still remains one).
Vertical Scaling is much more used in small and middle-sized companies and in applications and products of middle-range. Very common example for Virtual Scaling nowdays is to buy an expensive hardware and use it as a Virtual Machine hypervisor (VMWare ESX). Where a database is involved using Vertical Scaling without use of multiple virtual machines might be not the best solution, as even though hardware might suffice (creation of database locks might impose problems). Reasons to scale vertically include increasing IOPS (Input / Ouput Operations), increasing CPU/RAM capacity, and increasing disk capacity.
Because Vertical Scaling usually means upgrade of server hardware – whenever an improved performance is targeted, even though if Virtualization is used, the risk for downtimes with it is much higher than whenever horizontal scaling.

Horizontal Scaling (scale horizontally or scale out):- adding more processing units (phyiscal machine) to your server (infrastructure be it application web/server or database).
Horizontal scaling, means increasing  the number of nodes in the cluster, reduces the responsibilities of each member node by spreading the keyspace wider and providing additional end-points for client connections. The capacity of each individual node does not change, but its load is decreased (because load is distributed between separate server nodes). Reasons to scale horizontally include increasing I/O concurrency, reducing the load on existing nodes, and increasing disk capacity.
Horizontal Scaling has been historically much more used for high level of computing and for application and services. The Internet and particular web services gave a boom of Horizontal Scaling use, most companies nowadays that provide well known web services like Google (Gmail, Youtube), Yahoo, Facebook, Ebay, Amazon etc. are using heavily horizontal scaling. Horizontal Scaling is a must use technology – whenever a high availability of (server) services are required.

Apache SSLCertificateChainFile adding SSL with Certificate Chain / What is Certificate Chain

Friday, January 31st, 2014

configure-apache-ssl-certificate-chain-ssl-certificate-keychain-each-signing-each-other

If you work in a big company with large network infrastructure who has to deal with SSL Certificates you will sooner or later will have to learn about existence of SSL Certificate Chains.
Its worthy thus to know what is SSL Certificate Chains and how such a chain is configured in Apache?

Personal SSL certificates (certificates issued to an individual or a company) can be used by clients to uniquely identify themselves when they are involved in starting an SSL connection.
SSL Certificate file contains X.509 certificate, which, in turn, contains a public key used for encryption.
Each personal certificate has zero or more certificate chains of certification authority certificates that extend back to the root certification authority.
 

Certificate R (Root Certification Authority)
    |
    | represents issuer of
    V
Certificate I1 (Intermediate Certification Authority)
    |
    | represents issuer of
    V
Certificate I2 (A subsidiary Intermediate Certification Authority)
    |
    | represents issuer of
    V
Certificate I3 (A further subsidiary Intermediate Certification Authority)
    |
    | represents issuer of
    V
Certificate P (A personal certificate that is used to identify its owner 
               on an SSL handshake)

Certificate chains are used to verify the authenticity of each certificate in that chain, including the personal certificate. Each certificate in the chain is validated using its 'parent' certificate, which in turn is validated using the next certificate up the chain, and so on, from the personal certificate up to the root certification authority certificate.

Now after explaining thoroughfully what is SSL Certificate Chain, here is how to configure a SSL Certificate in Apache Webserver.

Open apache2.conf or httpd.conf (depending on GNU / Linux distribution) and add to it;

  SSLEngine On
   SSLCertificateFile conf/cert/webserver-host.crt
   SSLCertificateKeyFile conf/cert/webserver-host.key
   SSLCertificateChainFile conf/cert/internet-v4.crt
   # SSLCertificateChainFile conf/cert/intranet-v3.crt
   SSLOptions +StdEnvVars +OptRenegotiate +ExportCertData

SSLCertificateChainFile conf/cert/chain-cert.crt
loads a chain of separate Personal SSL certificates each signing each other on different levels, chain is leading to top ROOT CA (Certificate Authority).

Windows Explorer (Open directory in command prompt preserving dir PATH) – Add Dos Prompt Here feature via tiny registry tweak

Friday, January 10th, 2014

Windows explorer dos prompt here open directory in windows command line

If you have to use Windows on system administration level, you had to use command prompt daily, thus its useful to be able to be able to open Command Line starting from desired directory with no need to copy directory Path by hand and CD to it manually.

By default Command Prompt, cmd.exe always opens itself setting a path to user home directory, reading what is defined by win system variable %USERPROFILE% or %HOMEPATH% – MS Windows equivalent of UNIX's $HOME shell variable.

To add open in  DOS Prompt Here Command Prompt option to Windows Explorer menus its necessary to apply few rules to Windows registry DB
Use above Download link and launch it and from there on clicking with right Mouse button to any directory will enable you to open directory in CMD.EXE.

Here is content of little registry tweak adding the new menu Dos Prompt Here button
Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\DosHere]
@="Dos &Prompt Here"

[HKEY_CLASSES_ROOT\Directory\shell\DosHere\Command]
@="cmd.exe /k cd %1"

[HKEY_CLASSES_ROOT\Drive\shell\DosHere]
@="Dos &Prompt Here"

[HKEY_CLASSES_ROOT\Drive\shell\DosHere\Command]
@="cmd.exe /k cd %1"

Windows explorer open program files or any specific directory in windows command line

windows opening directory in command line program files screenshot win 7

This little registry code is originally for Windows 2000, anyways it is compatible with all NT technology based Windowses, Add DOS Prompt Here tweak works fine on Windows XP, Windows 7 and Windows 8 (Home, Pro and Business editions).

By Mentioning $HOME its interesting to say Windows equivalent of Linux's as it might be useful to know:

linux:~# echo $HOME
/home/hipo

is

C:\\> echo %USERPROFILE%
C:\\Users\\georgi

To list all Windows Command Prompt environment variable equivalent to Linux's bash shell env / setenv is SET command), here is example output from my Winblows;

C:\Users\georgi> SET
ALLUSERSPROFILE=C:\\ProgramData
APPDATA=C:\\Users\georgi\AppData\Roaming
CLASSPATH=.;C:\\Program Files (x86)\\Java\\jre6\\lib\\ext\\QTJava.zip
CommonProgramFiles=C:\\Program Files\Common Files
CommonProgramFiles(x86)=C:\\Program Files (x86)\\Common Files
CommonProgramW6432=C:\\Program Files\\Common Files
COMPUTERNAME=GEORGI
ComSpec=C:\\Windows\\system32\\cmd.exe
DEFLOGDIR=C:\\ProgramData\\McAfee\\DesktopProtection
FP_NO_HOST_CHECK=NO
HOMEDRIVE=C:
HOMEPATH=\\Users\\georgi
LOCALAPPDATA=C:\\Users\\georgi\\AppData\\Local
NUMBER_OF_PROCESSORS=4
OS=Windows_NT
Path=C:\\Program Files\\RA2HP\\;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\S
Wbem;C:\\Windows\\System32\\WindowsPowerShell\v1.0\;C:\\Program Files\\WIDCOM
oth Software\\;C:\\Program Files\\WIDCOMM\\Bluetooth Software\\syswow64;C:\\Pr
les (x86)\\Hewlett-Packard\\HP ProtectTools Security Manager\\Bin\\;C:\\Progr
\\ActivIdentity\\ActivClient\\;C:\\Program Files (x86)\\ActivIdentity\\ActivCl
\\Program Files (x86)\\QuickTime\\QTSystem\\
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
PROCESSOR_ARCHITECTURE=AMD64
PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 58 Stepping 9, GenuineIntel
PROCESSOR_LEVEL=6
PROCESSOR_REVISION=3a09
ProgramData=C:\\ProgramData
ProgramFiles=C:\\Program Files
ProgramFiles(x86)=C:\\Program Files (x86)
ProgramW6432=C:\\Program Files
PROMPT=$P$G
PSModulePath=C:\\Windows\\system32\\WindowsPowerShell\\v1.0\Modules\\
PTSMInstallPath_X86=C:\\Program Files (x86)\\Hewlett-Packard\\HP ProtectToo
ity Manager\\
PUBLIC=C:\\Users\\Public
QTJAVA=C:\\Program Files (x86)\\Java\\jre6\\lib\\ext\\QTJava.zip
SESSIONNAME=Console
SystemDrive=C:
SystemRoot=C:\\Windows
TEMP=C:\\Users\\georgi\\AppData\\Local\\Temp
TMP=C:\\Users\\georgi\\AppData\\Local\\Temp
USERDNSDOMAIN=EMEA.CPQCORP.NET
USERDOMAIN=EMEA
USERNAME=georgi
USERPROFILE=C:\\Users\\georgi
VSEDEFLOGDIR=C:\\ProgramData\\McAfee\\DesktopProtection
windir=C:\\Windows
windows_tracing_flags=3
windows_tracing_logfile=C:\\BVTBin\\Tests\\installpackage\\csilogfile.log

Hope this little trick hopes someone out there.
I will be glad to hear of other cool useful windows registry tweaks?

 

Checking I/O Hard Disk (Overhead) Read / Write operations on Microsoft Windows 7 – Resource Monitor

Friday, July 26th, 2013

I mainly have to deal with Linux servers. Today however I had to check for problems Microsoft Windows 7 server. The machine looked Okay but was reading from hard drive all the time. Hence I needed to check what is the Hard disk approximate read / write speed per second. I know on lInux tracking i/o hard disk server bottlenecks is done with iostat or dstat.

However I never did that on Windows, so I had to learn it by experience. Its actually pretty easy and you don't even need to install external program to see read / write hdd speed operations. Windows 7 is bundled with a Program called Resource Manager. Running Resource Manager's easiest method is from Windows Task Manager, i.e.:

Windows 7 Task Manager processes performance tab - how to check hard drive bottleneck windows server
Press Ctrl + Alt + Del (Choose Start Task Manager) and from Task Manager click on Resource Monitor Button.
Immediately resource Monitor pops up and selecting the Disk tab priovides information on HDD Read / Write speed per sec. Using Resource Monitor, you can quickly also see which process is creating the most HDD overhead for server.

microsoft windows 7 resource monitor screenshot

windows resource monitor disk tab hard disk show read write speed win7

Though I'm not Microsoft fan, I should admit Resource Manager does a great job.

 

12 разбойников / Жило 12 разбойников – Руская православно-народная песен

Monday, November 19th, 2012

12 разбойников / Жило 12 разбойников – Руская православно-народная песен On the Church service in Nijmegen in the Serbian Orthodox Church today, there were Rusian priest guests invited by on e Dutch orthodox person who sings in Russian Orthodox Church choire in Nijmegen. The priest came from saint Peterburg Russia. The serving priest was father Sergii, he came with a deacon. The usual Saint John of Crysostom holy liturgy was served by the Russian priest Father Sergii, who was also with a deacon (I think also from st. Peterburg). The church service as every Church service was a great experience for all orthodox. After the end of service in the traditional way as they do it here, all brothers from the Church had a sort of Agape small meal together. I traveled to Nijmegen with Father Dushan who was kind enough to take me with his car Wolkswagen to the Byzantine Capel Church in Nijmegen. As the serving priest and the deacon was guest priests, father sergii asked them to sing a traditional Russian-Church folklore song called 12 Robbars (Burglars)
I hear the song for a first time, and I found it quite beautiful and decided to reshare for people. It seems 12 Разбойников is a song well known by Russians, but maybe less known among non-Russians. Enjoy 🙂

Иван Ребров – Жило двенадцать разбойников Jilo 12 Razboinikov is a song telling a story about 12 Burglars, who killed a lot of Christian and stole a lot of treasures while stalking in the woods. But a big change happened in them as they repented and become monks and prayed to God asking for forgiveness of their sins and asking for mercy of them and the whole world. Really nice piece of Spiritual Song.

By the way the Spiritual Living of the Parohija (as Serbians call their parish) headed in Nijmegen here by Father Dushan is quite rich. Just two weeks ago there was a great deal happening as two Serbian Church Bishops came for the feast of birth of Saint Constantine and Remembrance of saint Constantine and Helena (which took place in Nish nowdays Serbia (ex-Yugoslavia).

I heard from Father (Hieromonk) Dushan who is serving in the 3 Serbian Orthodox Churches here in Holland (in Breda, Nijmegen and Amsterdam), that next month (December 2012) here in Serbian Orthodox Church Nijmegen a guest priest will come from Syriac orthodox Church (belonging to Antiochian Patriarchy) to serve a Holy Liturgy in Arabic! Will be interesting to see.
Deacon holding Holy Chastice

Father Sergii from St. Peterburg Holding Holy Chastice

Srpska cyrkva parohija eparchy all people after Church Service Holy Liturgy picture zaedno

All people from Eparchy Orthodox Serbian Church Nijmegen  picture in front of Alter wall

Serbian Chetec (Holy Bible reader) and ipodiakonus with Father Sergii blessing the in Holy Liturgy

 

Русская народная песня "Жило 12 разбойников" Ali Askerov

Don’t revoke GoDaddy SSL certificate. (Expired) Revoked SSL is impossible to revert

Thursday, April 12th, 2012

godaddy_logo
One of our company SSL (https) Certificates recently expired so I needed to renew the SSL certificate.

I was in a hurry doing plenty of other stuffs so it seemed logical for me to Revoke the Certificate. I thought revoking the certificate will simply cancel it and afterwards, in Godaddy's SSL (Manager Certificates) interface the Revoked – Cancelled certificate will re-appear in the menu, ready to be generated in the same way as earlier I initially generated the Godaddy's bought SSL certificate

Hence I proceeded and used Revoke button:

Godaddy SSL certificate manager browser certificate Screenshot

Well guess what my calculations, were wrong.
 Revoking, just cancel it. The  revoked domain SSL certificate did not show up again in Godaddy's Cert Manager and I have no way from their interface to revert the changes.

To deal with the situation, I contacted Godaddy Support immediately with the following inquiry:
 

Other : Revoked SSL Certificate
Issue :
Hello we have revoked the SSL certificate for our domain our.domain-name.com.
 Can we revert back the certificate as it was.
If not how to generate a new key for our domain https://our.domain-name.com
Thanks in Advance.
Kindest Regards

"My-Company-name" Tech Support

In 5 hours time I received the following tech support answer:
 

Dear Tech Support,

Thank you for contacting Online Support. It is not possible to reinstate a canceled certificate. You will need to purchase a new certificate. I have requested that a refund be applied to your account. Once the credit appears in your account, please allow 5-7 business days to see the funds applied to the associated payment method. Thank you for your patience and understanding in this matter.

Please let us know if we can help you in any other way.

Sincerely,

Christian P.
Online Support Team
Customer Inquiry
Name : Cadia Tech Support
Domain Name : our.domain-name.com
ShopperID : xxxxxxxxx
Phone : xxxxxxxx
Shopper Validated : Yes
Browser : Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3

Apparently Godaddy, can work out a bit on their tech support answering time 5 hours for a simple reply is quite long.

Now taking in consideration, above reply from Godady, my only options are to either wait for 5 to 7 (business days) or buy a new credit for SSL certificate.

Buying a new credit will probably not happen as our company is experiencing some financial troubles because of the crisis. So I guess we will have to wait for this 7 days at worst. So again if you wonder to REVOKE or not an SSL certificate. Think again …

Just a small note to make here, that Godaddy has a very straight forward way to just renew an expered certificate, which I succesfully later have done for 4 domains. Well, if only I knew earlier what REVOKE SSL cert really does I wouldn't have ended in this mess …

Back on the Road Again

Saturday, February 17th, 2007

Yesterday I’ve went through a depression. The depression is trying to hunt me periodically. Right now I feel soso.So Praise the Lord. Yesterday I found out I passed the Accounting exam this was a great deal (thanks LORD).Today since it’s Saturday I hoped I will be able to sleep until 2, 3 o’clock unfortunately Tisho came andwake me up. Tisho is a friend I borrowed some money a week and a half ago. I can’t communicate normally with thisguy I don’t know why … We went to Mitko to take him for a coffee. e was playing Mugen ( A StreetFighter likecool fighting game). We stayed their for 30 minutes probably and then went to the fountain for a coffee.It was boring as a whole we smoked some cigaretes then everybody went to his home. When I cameback I upgraded the PHP modules on two of the boxes of DBG and right now I upgraded the clamav release.Meanwhile My boss make some interviews for a new server admin in the firm. One friend Joro went on the Interviewand the Boss approved him for the Job. What I am wandering and feeling about is, will this be me substitutionin the firm or this will be just another local administrator for the office. Actually I hope this thing wouldhappen that God has thought about me. I wait for the Lord to direct my way to somewhere since I’m in theocean as and no Land can be seen, just like I dreamed in one of my dreams before few months.In 5 o’clock I’ll meet Joro to speak about him how his interview in DBG went and possibly what will behis exam. ( I’ll be the examiner :]). Static come home yesterday and told me the dream he had the previousnight. He dreamed the Lord Jesus Christ. Here is the dream.Our saviour was standing on a platform of a sort of cloudsand a lot of people were around him. He was all in light and everything around was light,there were 4 pillars ending in a sort of a sky. Jesus was all in white (white more whiter than any light in the world we can observe), he was with long White beard and Long white hair.Then my friend who dreamed this dream just thought in his mind “Oh Lord that’s you.”Then the Lord Jesus Christ pointed at him and he started ascending into the skies, full of very deep joy.After that he just woke up and prayed. Well Praise the Lord for giving to one of my brothers such a wonderfuldream. I hope his mercy will guard us all. Let Christ’s peace be in our hearts. AmenEND—–