VMware Vcenter corruption

By , March 3, 2014 4:27 PM

mount -n -o remount,rw /

e2fsck -f /dev/sda3

DELL WIRING

By , February 10, 2014 1:50 PM

0 VMN A0
1 VMN A1
2 SCSI A0
3 SCSI A1
4 SCSI B0
5 SCSI B1
6 VMN B0
7 VMN B1

Duplicate Outlook 2013 Calendars and how to remove them

By , January 30, 2014 6:23 PM

Can you restore the .pst? It needs unloading from outlook before just deleting it.

If not:

You can solve the errors rather easily – just remove the data links in ‘Control Panel’/'Mail’/[Data Files]. Don’t do this yet.

See if you have options to remove the calendars there (probably not – now would be a good time to backup/export the working PST+calendar) and do so.

If you can still expand the contents of the deleted .pst in the Navigation pane then goto the folder view and right click and delete the offending calendar. More than likely you won’t have this option so just remove the data files from the Account window (as mentioned above).

If the calendars are still showing, do you have the option of unselecting them from the Calendar window?

Kanel and Moxa

By , January 19, 2014 10:26 AM

Hi

I use terminal servers since over 5 years with no problems.

As Cezary said, you should use rawtcp or telnet mode to conect to the
modems connected to your moxa device. Therefore no need to install any
driver nor kernel module. That is only needed if you want your OS to
show ethernet port as a virtual local serial port and then have kannel
connected to the local virtual serial port.

You should define each of your modems with its IP and port so kannel
will connect directly to it via TCP/IP:

group = smsc
smsc = at
smsc-id = modem1
log-level = 0
modemtype = auto
speed = 115200
log-file = “/var/log/kannel/modem1.log”
allowed-smsc-id = modem1;modem3
sim-buffering = true
keepalive = 60
max-error-count = 8
################################
#### SETTINGS PARA ACCESO VIA
#### TERMINAL SERVER
device = rawtcp <<<<<<<<< THIS SETUP WILL ALLOW YOU TO
host = 10.10.5.3 <<<<<<<<< CONECT DIRECTLY TO YOUR MODEM
port = 2100 <<<<<<<<<< ON THE MOXA DEVICE

Hope helps

Regards

Alvaro

On 6/1/12, Cezary Siwek wrote:
> Hi,
>
> Long time ago I’ve been playing with a regular serial modems + terminal
> server.
> The terminal server exposes each modem on a different tcp port. In the
> kannel you use either ‘rawtcp’ or ‘telnet’ smsc type.
> It worked fine for a several years.
>
>
>
> Regards,
> Cezary
>
>
> On 01/06/2012 10:57, Peter Valdemar Mørch wrote:
>> Hi,
>>
>> We’ve been using Falcom and Tango modems in the past, but they’ve been
>> difficult to buy lately. Instead we’re considering buying “Moxa
>> OnCell” or “Siemens MC35i” (which appears to be identical to
>> “Cinterion MC35i”).
>>
>> Now that we’re looking to test and buy new modems anyway, we’d love
>> some that work better in VMware ESX environments where access to
>> serial ports isn’t possible. All the above modems except the “Moxa
>> OnCell” are accessed via a serial port.
>>
>> E.g. something that holds a SIM card, has an IP address and provides
>> an SMPP interface would be perfect, but I realise I’m a novice in this
>> field.
>>
>> So far in VMware, we’ve been setting up Moxa Serial Device Servers (
>> http://www.moxa.com/product/Serial_Device_Servers.htm ) that via a
>> kernel module in the ESXi virtual host provide access to a
>> pseudo-serial port. That is flaky at best. The “Moxa OnCell” also
>> needs a kernel module, and we haven’t yet had success with it.
>>
>> I’ve read http://kannel.org/compatibility.shtml but I haven’t been
>> able to find a vendor for any of the “Phones that works as SMSC’s with
>> Kannel”. At least two of the three are no longer being produced, but I
>> think they all used serial port access, and so don’t work so well
>> under VMware.
>>
>> So in short, I’m looking equipment/solutions recommendations that
>> allow us to send SMSes from both real hardware and VMware ESX guests
>> using our own SIM card (not a remote hosted solution), using hardware
>> that is still current and in production and without kernel
>> modules/patches.
>>
>> Does such equipment exist? What do you recommend?
>>
>> Thank you for reading this far.
>>
>> Peter
>
>

SMS Servers

By , January 9, 2014 4:02 PM

SMS Tools

http://blog.biolizards.be/setting-up-a-smsgateway-part1/

http://smstools3.kekekasvi.com

PLAY SMS

http://playsms.org/

KANNEL

http://inuits.eu/blog/sms-server-using-centos-kannel-and-playsms

GOIP

http://blog.voptech.com/install-goip-sms-manager-server/#.Us45lvvhd8E

http://www.dbltek.com/pdf/GOIP_SMS_Server_English_Manual.pdf

http://www.ozekisms.com/index.php?owpn=697

GOIP

http://www.ultrative.com/down/UTT-GoIP_Manual.pdf

https://github.com/tangaza/Tangaza/wiki/Connecting-a-GoIP-GSM-VoIP-gateway-to-an-Asterisk-AGI

By , December 30, 2013 12:39 PM

thread_cache_size: Thread creation/destructions can be expensive, which happen at each connect/disconnect. I normally set this value to at least 16. If application has large jumps in amount of concurrent connections and I see fast growth of Threads_Created variable I boost it higher. The goal is not to have threads created in normal operation. See http://www.mysqlperformanceblog.com/2006/09/29/what-to-tune-in-mysql-server-after-installation/

The number of threads that are kept in the cache for reuse. This variable can be increased to improve performance if you have a lot of new connections. Increasing this value increases the number of file descriptors that mysqld requires. See http://www.interworx.com/support/docs/nodeworx/mysql/howto-mysql-options

thread_cache_size: How many threads the server should cache for reuse. When a client disconnects, the client’s threads are put in the cache if there are fewer than thread_cache_size threads there. Requests for threads are satisfied by reusing threads taken from the cache if possible, and only when the cache is empty is a new thread created. This variable can be increased to improve performance if you have a lot of new connections. Normally, this does not provide a notable performance improvement if you have a good thread implementation. However, if your server sees hundreds of connections per second you should normally set thread_cache_size high enough so that most new connections use cached threads. By examining the difference between the Connections and Threads_created status variables, you can see how efficient the thread cache is.

**Threads_created (status variable): The number of threads created to handle connections. If Threads_created is big, you may want to increase the thread_cache_size value. The cache miss rate can be calculated as Threads_created/Connections. **

Connections (status variable): The number of connection attempts (successful or not) to the MySQL server.

Threads_connected: The number of clients currently connected to the server. If its value is often close to the value of max_connections, it might be good to increase the value of max_connections to allow more connections. If clients that should be able to connect frequently cannot, that too is an indication that max_connections is too small. Each active connection handler / thread requires some memory, so you don’t necessarily want to set max_connections to the number of threads allowed by the operating system.

Each thread that is used to manage client connections uses some thread-specific space. The following list indicates these and which variables control their size:

A stack (default 192KB, variable thread_stack)
A connection buffer (variable net_buffer_length)
A result buffer (variable net_buffer_length)

The connection buffer and result buffer both begin with a size given by net_buffer_length but are dynamically enlarged up to max_allowed_packet bytes as needed. The result buffer shrinks to net_buffer_length after each SQL statement. While a statement is running, a copy of the current statement string is also allocated. See http://www.learn-mysql-tutorial.com/TuneMySQL.cfm

MYSQL Tuning

By , December 30, 2013 12:39 PM

MyISAM Key Buffer Usage

 key_buffer_size

For MyISAM one of the most important variables is the Key Buffer.  The Key Buffer is sometimes called the Key Cache. It’s used as a buffer for the indices of MyISAM tables. There is some overhead in the buffer depending on the configured key block size.

Set up to 30-40% of available memory if you use MyISAM tables exclusively. 2-4 MB minimum; dedicating GBs can be a waste.

 

 

 

 

thread_cache_size:
Thread creation/destructions can be expensive, which happen at each connect/disconnect. I normally set this value to at least 16. If application has large jumps in amount of concurrent connections and I see fast growth of Threads_Created variable I boost it higher. The goal is not to have threads created in normal operation. See http://www.mysqlperformanceblog.com/2006/09/29/what-to-tune-in-mysql-server-after-installation/

The number of threads that are kept in the cache for reuse. This variable can be increased to improve performance if you have a lot of new connections. Increasing this value increases the number of file descriptors that mysqld requires. See http://www.interworx.com/support/docs/nodeworx/mysql/howto-mysql-options

thread_cache_size: How many threads the server should cache for reuse. When a client disconnects, the client’s threads are put in the cache if there are fewer than thread_cache_size threads there. Requests for threads are satisfied by reusing threads taken from the cache if possible, and only when the cache is empty is a new thread created. This variable can be increased to improve performance if you have a lot of new connections. Normally, this does not provide a notable performance improvement if you have a good thread implementation. However, if your server sees hundreds of connections per second you should normally set thread_cache_size high enough so that most new connections use cached threads. By examining the difference between the Connections and Threads_created status variables, you can see how efficient the thread cache is.

**Threads_created (status variable): The number of threads created to handle connections. If Threads_created is big, you may want to increase the thread_cache_size value. The cache miss rate can be calculated as Threads_created/Connections. **

Connections (status variable): The number of connection attempts (successful or not) to the MySQL server.

Threads_connected: The number of clients currently connected to the server. If its value is often close to the value of max_connections, it might be good to increase the value of max_connections to allow more connections. If clients that should be able to connect frequently cannot, that too is an indication that max_connections is too small. Each active connection handler / thread requires some memory, so you don’t necessarily want to set max_connections to the number of threads allowed by the operating system.

Each thread that is used to manage client connections uses some thread-specific space. The following list indicates these and which variables control their size:

  • A stack (default 192KB, variable thread_stack)
  • A connection buffer (variable net_buffer_length)
  • A result buffer (variable net_buffer_length)

The connection buffer and result buffer both begin with a size given by net_buffer_length but are dynamically enlarged up to max_allowed_packet bytes as needed. The result buffer shrinks to net_buffer_length after each SQL statement. While a statement is running, a copy of the current statement string is also allocated. See http://www.learn-mysql-tutorial.com/TuneMySQL.cfm

CENTOS ADDING VM TOOLS

By , November 24, 2013 2:44 PM

From the VM’s local console (not SSH, as the network changes will disconnect you):

yum install gcc kernel-devel
yum -y upgrade kernel kernel-devel
reboot

(In your VMware console, select VM -> Install VMware tools):
(Log back into the local console of your Centos VM and continue):

mount /dev/cdrom /mnt
ls /mnt

(make note of the name of the vmware tools tgz file you see in the listing, and replace [name of vmware tools file], below, with it.):

tar -C /tmp -zxvf /mnt/[name of vmware tools file]
cd /tmp/vmware-tools-distrib
./vmware-install.pl

“Y” on the first prompt, then defaults (just press enter) on the rest should be fine.
./vmware-install.pl  # add -d to auto accept defaults
Important:
Follow the instructions that vmware-install.pl will give you at the very end of its run for updating your network card to the vmxnet3 driver. It will be a short list of commands to type in.

CENTOS MINIMAL Configuring the Network

By , November 24, 2013 2:26 PM

The command ip a s is used to display our current interfaces . The one we are interested in is “eth0″. Currently their is no IP address assigned and the interface is indicating that it is in a DOWN state.

To configure “eth0″ to obtain an IP address automatically, we need to check that it is using “dhcp” and that the interface should be started automatically at boot”. We can check the current configuration by navigating to “/etc/sysconfig/network-scripts”. Our interface configuration is stored in a file called “ifcfg-eth0″.

 

DEVICE=eth0
HWADDR=08:00:27:C3:1F:C8
TYPE=Ethernet
UUID=399e364f-e278-4969-9dc7-3481618ede62
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=dhcp

Once you have made your changes and saved these. You will need to restart your network services with the command:

 service network restart
Now if we issue the command ip a s we should see that our interface has now been assigned an IP address.

APC network card

By , November 12, 2013 6:46 PM

We deploy a lot of uninterruptible power supply units throughout our network. The deployment of VoIP has made those units even more important as we plan for power failure contingencies. Occasionally we find one or two that are miss-configured. Here are the steps to resetting the username and password of the APC network management cards. You’ll need to use a serial cable (2400,8,N,1) to attach to the UPS in order to reconfigure the management card.

Press ENTER, repeatedly if necessary, to display the User Name prompt. Press the Reset button on the back of the card. The Status LED will flash alternately orange and green. Press the Reset button a second time immediately while the LED is flashing to reset the user name and password to their defaults temporarily.

Then press ENTER as many times as necessary to redisplay the User Name prompt, then use the default, apc, for the user name and password. (If you take longer than 30 seconds to log on after the User Name prompt is redisplayed, you must repeat step 5 and log on again.)

You should immediately reconfigure the appropriate username and password (select System, then User Manager, select Administrator).

 

 

To add some helpful tips, make sure that the serial port is not being used by any application such as PCBE if there’s any. If you can see multiple COM ports on HyperTerminal please do try all those as well.

Another thing would be, removing the network management card on the UPS and then connect to your UPS using the cable that kulotz gave you before. Using HyperTerminal set it to 2400, 8, None, 1, None, XOn/XOff. Once you are connected kindly press Shift+Y and then Shift+A. Pressing Shift+Y, it should respond back with an “SM” message while Shift+A should make your UPS flash the LEDs and produce a beep sound.

Hope this helps.

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