Category: Uncategorized

Ever tried logging into a machine with ssh and found you have to wait much longer than reasonable for the session to start? This happened to me a few times and was especially annoying with machines on my local network (or a VM attached to a virtual network) that should be letting me in immediately. Basically the session is slow to start because the SSH server is trying to lookup the hostname of the SSH client and for whatever reason it’s timing out (e.g., it can’t reach a nameserver, because you happen to be offline) There are a couple of very simple ways to fix that: add “UseDNS no” to /etc/ssh/sshd_config add the client’s net address to the server’s /etc/hosts

We had this issue copying large amounts of data to this Western Digital My Book Live Duo NAS.

It was mounted up on a Oracle Centos 6.5 VM but once we hit a file over 1GB in size, the machine would halt. Turns out we have to map the drive using the option protocol=udp like the following statement:

mount 192.168.1.45:/nfs /transport -o soft,timeo=60,intr,proto=udp

 

See, NFS mount by default uses TCP, but for Linux to work with this drive it needs to use UDP.

On your current stack, ssh in and at the config prompt, enter:

stack unit 2 provision S50V

stack-unit 3 provision S50V

the number is the number of the switch you’re introducing, and the S50V is the model of the switch, you can use S25N, S25P, S25V, S50N, and S50V.

On your new switch make sure you renumber the thing at the enable prompt like this:

stack-unit 0 renumber 2

stack-unit 1 renumber 3

 

Make sure you write out your config file!

http://www.cyberciti.biz/faq/fedora-rhel-install-cacti-monitoring-rrd-software/

/etc/vmware-tools/services.sh restart

Open up the Exchange Management Console, go down to Server Configuration, select Hub Transport.

Click New Receive Connector fill out all the important name values and network values.

Double check your work,

Ensure that Anonymous users has a check box:

Ensure that only your local network has access to the Exchange Server.

VMware image customization is in progress … at every reboot

When rebooting a virtual machine (server 2008 R2 x64 in this example) in vSphere 5 you see the following:

loading:

followed by:

To resolve this open regedit and browse to HKLM, System, CurrentControlSet, Control, Session Manager:

Open the BootExecute key:

Change the BootExecute key from this:

to this:

Reboot.

Check if your system is setting the environment variable TMOUT. To check this you can just do:

env | grep TMOUT

or

echo $TMOUT

If it is set, you could change it or unset it. To change the value:

export TMOUT=3600

Where the number is the number of seconds until you get logged out. Otherwise unset it to turn off the feature:

unset TMOUT

Note, it may be that your system administrator has set this for security reasons. So if you are not the system administrator you may want to check this before changing anything yourself.

In the NSC*.ini file you will find a password parameter and you need to put your SNMP community string. Mine seemed to need it here.

NSC*.ini excerpt

; ;# PASSWORD ; This is the password (-s) that is required to access NSClient remotely. If you leave this blank everyone will be able to access the daemon remotly. password=public ;

So yet another issue with HBAs this time with an older QLogic qle2462 and a set of 12TB Promise Arrays. Save your self some trouble and download the driver from VMware, qla2xxx-934.5.4.0 and inject it into your Update Manager…