Unable to start Vcenter service due to DB Error “Suspect vCenter database on SQL Express”.


Error:

We unable to start Vcenter and their dependency service which throws an error in Event viewer Event-ID 7031 and 7024. Also we check the ODBC connectivity for the Vcenter DB where the test is not successful.

When we check the Vcenter DB in the SQL management studio it displays with yellow asterisk  and the error as VIM_VCDB(Suspect) as shown in the image below.

 

 

 

 

 

Root cause:

There can be many reasons for a SQL Server database to go in a suspect mode when you connect to it – such as the device going offline, unavailability of database files, improper shutdown etc..

Solution:

In order to have more information on why the database is Suspect, you just need to execute the following SQL command

Step -1: DBCC CHECKDB (‘YourDBname’) WITH NO_INFOMSGS, ALL_ERRORMSGS

In order to repair the database, we need to run some SQL command :

Step – 2: EXEC sp_resetstatus ‘VIM_VCDB’

Step -3: ALTER DATABASE VIM_VCDB SET EMERGENCY

Step -4: ALTER DATABASE VIM_VCDB SET SINGLE_USER WITH ROLLBACK IMMEDIATE

The stored procedure sp_resetstatus turns off the suspect flag on a database. This procedure updates the mode and status columns of the named database in sys.databases

The EMERGENCY mode marks the database READ_ONLY, logging is disabled, and access is limited to members of the sysadmin fixed server role.

The SINGLE_USER specifies that only one user at a time can access the database (mandatory for repair with DBCC CheckDB)

Step -5: DBCC CheckDB ('VIM_VCDB', REPAIR_ALLOW_DATA_LOSS)

This command will try to repair errors. Theses repair could cause data loss.

Step -6: ALTER DATABASE VIM_VCDB SET MULTI_USER

We put database in production state. It has no longer the Suspect flag and can be accessed as usual.

 

 

 

 

 

 

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Windows Calculator vs. Qalculator


  1. In normal Windows calculator conversion of Money rates is not possible and also there is no plugin available to fetch the data from internet, but qalculator does this. It requires internet to fetch the data.
  2. Microsoft mathematics is also a very good tool which competes with qalculator.
  3. Electrical and many Engineering calculation is available in Qcalculator, but windows OS calculator no option available and Microsoft mathematics minimum is available.
  4. Qcalculate is very simple whatever calculation we require we simply type and get the result.

Download for Microsoft mathematics url : http://www.microsoft.com/en-us/download/details.aspx?id=15702

For Qalculate : $ sudo apt-get install qalculate ( Qalculate supports in Linux os only)

This calculator will be more useful for Engineering calculation, design and other complex calculation.

Some of the screenshots are shared below.

I. Qalculate

 

 

 

 

 

 

 

 

 

 

 

 

 

II. Windows Mathematics

 

 

 

 

 

Problem Steps recording


Today I come across an interesting tool in windows 7, which is very useful when you need to create continuous screen shot documentation. This will be very useful for those who find root cause analysis to a problem or to a QA team.

It’s intended for users to capture step by step actions and screenshots to illustrate a problem and can save you a lot of time.

To run this command go to command prompt and type as below

C:\> psr  (or) Go to start and select run type psr

 

 

Cool options in NMAP command


1.To identify how many Windows and Linux OS in a LAN environment.

Eg:

# nmap -F -O 192.168.1.1-15 | grep “Running: ” > /tmp/os; echo “$(cat /tmp/os | grep Linux | wc -l) Linux device(s)”; echo “$(cat /tmp/os | grep Windows | wc -l) Window(s) devices”

Output will be displayed like

0 Linux device(s)
1 Window(s) devices
#

2.To do an IDS scan or attack which gives a brief report such as

a.OSversion
b.Open ports
c.Network distance (How many hops to reach a particular server or pc)
d.Uptime of the server

Eg:
# nmap -T Aggressive -A –v IP Address or hostname

Customized output

Discovered open port 3389/tcp on IP Address
Discovered open port 5900/tcp on IP Address
Discovered open port 135/tcp on IP Address
Discovered open port 5800/tcp on IP Address
Initiating OS detection (try #1) against  Hostname or IP address
Host is up (0.0012s latency).
Device type: general purpose
Running: Microsoft Windows 7|2008
OS CPE: cpe:/o:microsoft:windows_7 cpe:/o:microsoft:windows_server_2008::sp1
OS details: Microsoft Windows 7 or Windows Server 2008 SP1
Uptime guess: 0.097 days (since Fri Nov  9 09:24:21 2012)
Network Distance: 2 hops

How to identify the remote machine mac address in windows


There are n numbers of tools available to identify the mac address of windows machine. But interestingly there is also a command available in windows to identify MAC address of remote machine. The syntax is given below.

Eg:

C:\> getmac /S  hostname or IP address

Physical Address    Transport Name

=================== ==========================================================

6C-62-6D-CF-BF-99   \Device\Tcpip_{E288B8E7-55F9-45AD-B292-08C9066EF878}

N/A                 Hardware not present

My OS Environment: Win7 Professional.

YouTube-dl Proxy configuration


To my subsequent topic on youtube-dl, I am posting an update on this topic (i.e.) when you get a below error message when you try download videos from Youtube-dl.

Error: – “urllib2.URLError: <urlopen error [Errno 110] Connection timed out>

Trace back (most recent call last):

urllib2.URLError: <urlopen error [Errno 110] Connection timed out>

Warning: unable to set language: <urlopen error [Errno 101] Network is unreachable>”

I reduced the above error messages and posted  only vital error message.

Root cause:

  1. If your computer is connected with direct internet connection and you are getting the above error message, you need to check with ISP DNS address or network.
  2. If you access the internet through network proxy and you are getting an above error message then you miss the proxy configuration in .bashrc file.

Solution:

Please do the proxy configuration in your .bashrc file available in /home/user/.bashrc ; for  root user /root/.bashrc

export http_proxy=http://127.0.0.1:3128

export https_proxy=https://127.0.0.1:3128

export ftp_proxy=ftp://127.0.0.1:3128

export http_proxy=$http_proxy

export https_proxy=$https_proxy

export ftp_proxy=$ftp_proxy

This solves the problem.