Gkhan Tips - Page 5 of 32 - Gkhan IT Tips for Systems and Network Administrators

VMware ESXi Datastores refresh issue incorrect free space

We do manual datastore scan or HBA scan to show the correct free space .

We can change the refresh interval manually to edit config.xml file in esxi host.

To change the refresh interval, edit the configuration file and change the refreshInterval value to the desired interval.

To change the refreshInterval value:

Using a text editor, open the /etc/vmware/hostd/config.xml file on the host.
Locate the <datastore> element. This element in the default file is similar to:<datastore>        </datastore>
Remove the comment indicators and replace the 0 (zero) in the <refreshInterval> element with the desired number of minutes. For example, to set the refresh interval to one hour, change this line:
to:

<refreshInterval>60</refreshInterval>
Save and close the file.
Restart the hostd service for the changes to take effect.
/etc/init.d/hostd restart

Continue reading VMware ESXi Datastores refresh issue incorrect free space

Select your Cisco Switch

Quickly identify the right Cisco switch for your needs—whether you’re acquiring a new switch or upgrading an old one.

Just answer a few simple questions and get your results. It’s that easy, so let’s get started.

Cacti Table ‘host’ is marked as crashed and should be repaired

My Cacti server lost all host information and on monitor tab its showing error “Table ‘host’ is marked as crashed and should be repaired”

I tried google got below solution that worked for me .I got my all devices back to monitor.

go to cli directory /var/www/html/cli/

and run command “php repair_database.php”

[root@localhost ~]# cd /var/www/html/cli/

[root@localhost cli]# php repair_database.php
Repairing All Cacti Database Tables
Repairing Table -> ‘cdef’ Successful
Repairing Table -> ‘cdef_items’ Successful
Repairing Table -> ‘colors’ Successful
Repairing Table -> ‘data_input’ Successful
Repairing Table -> ‘data_input_data’ Successful
Repairing Table -> ‘data_input_fields’ Successful
Repairing Table -> ‘data_local’ Successful

Continue reading Cacti Table ‘host’ is marked as crashed and should be repaired

Could not create the java Virtual Machine

When that happens, the easiest solution that has been tested on Windows XP, Windows 7 and Windows 8 is:
Continue reading Could not create the java Virtual Machine

How to install CentOS on Remote Server or VPS

If you want to install CentOS remotely on server on slow link even if you are able to mount the CentOS installation media as DVD iso .It takes lots of time and some time corrupted installation .

Linux is having a feature Netinstall you can use that feature and install the CentOS as version you want.

1- Download the Netinstall bootable media ISO file version you would like to install.

http://archive.kernel.org/centos-vault/

For demo I am going to install CentOS 5.5 32 bit

1- I went to following directory

http://archive.kernel.org/centos-vault/5.5/isos/i386/

Continue reading How to install CentOS on Remote Server or VPS

How to Show All NAT Tables Rules IPTABLES

iptables -t nat -L
iptables -t nat -L -n -v | grep 'something'
iptables -t nat -L -n -v

The netstat-nat command display the natted connections on a Linux iptable firewall

yum install netstat-nat

# netstat-nat -n
To display SNAT connections, run:
# netstat-nat -S
To display DNAT connections, type:
# netstat-nat -D

List NAT

iptables -t nat –line-numbers -L

Delete rule no 6

iptables -t nat -D PREROUTING 6

How to scan HBA Vmware ESXi Vmware Power CLI

Connect to your ESX or VCenter Server

Connect-VIServer -Server 192.168.1.10 -Protocol https -User Administrator@vsphere.local -Password P@ssw0rd

To Scan all ESXi hosts is Cluster
Get-Cluster ‘cluster name‘ | Get-VMHost | Get-VMHostStorage -RescanAllHba

To scan single ESX host

Get-VMHost ‘192.168.1.11‘ | Get-VMHostStorage -RescanAllHba

How to Bring Up a SVI Interface Cisco Switch

SVI must meet all of the following conditions to transition to the full “up/up” state.

1- The VLAN must exist and be active in the VLAN database.

2- At least one switched port in the VLAN (access or trunk) must be up.

3- That port must be in the STP forwarding state.

Sometimes it is necessary to have that VLAN interface up even if there are no devices or ports using that VLAN

simply forced the VLAN into an “up/up” state. Issuing the “no autostate” command on the VLAN interface will bring the interface up. Basically, the command just tells the VLAN interface to ignore the above mentioned prerequisites. Note: This command is only available in certain IOS images.

Source link

How to enable ESXi SSH And ESXi Shell Using PowerCLI

Connect to the VCenter Server

#Connect to VCenter Server 
Connect-VIServer -Server 192.168.10.1 -Protocol https -User Administrator@vsphere.local -Password P@ssw0rd

#Now Check which serveries are running and you want to start or stop
Get-VMHost 192.168.10.11 | Get-VMHostService

Now you will get slimier to below screen

Continue reading How to enable ESXi SSH And ESXi Shell Using PowerCLI

no “setup” command found in CentOS minimal install

In Minimum Install this will not get install

If we got below Error, we need to install some packages to get work with setup command

[root@gkhan.in ~] setup
-bash: setup: command not found

Here we can see how to install in minimal install

yum install setuptool -y
yum install system-config-network* -y
yum install system-config-firewall* -y
yum install system-config-securitylevel-tui -y
yum install system-config-keyboard -y
yum install ntsysv -y

Now we can use the setup utility, That’s it.