Disk IO check

You’ll need to get iostat for this.

yum install sysstat should get you what you need.

iostat -x 2 

This will give you a picture of your disk usage every two seconds. Adjust the number at the end to your liking. 

Here’s an example output:

iostat

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Escaping SSH session

If you find yourself trapped inside a SSH session that is hung, while SSH’d into another machine? I have, often actually. Sometimes I’m connected and reading up on something and when I come back my session has loss its connection while I was ssh’d into another machine. Here’s how you can back out to the other machine:

In the shell type: ~.

that’s a period at the end of the tilde. This will terminate your connection and bring you back to the shell you where SSH’d into prior to that.  

 

source:
http://rcsg-gsir.imsb-dsgi.nrc-cnrc.gc.ca/documents/internet/node30.html

http://rcsg-gsir.imsb-dsgi.nrc-cnrc.gc.ca/documents/internet/node30.html

scanning for scsi devices in CentOS 6

 

 

 

Recently I ran into a situation where passing the “- – -” values to iscsi_host/host#/scan didn’t work for me. I was sure that I had run this before on CentOS6, but to no avail I could not find a value in the /host portion.

 

So, this what I discovered! The friendly folks at Red Hat have created a script for dealing with this.

 

Do this:

 

1. yum install sg3_utils
2. run rescan-scsi-bus.sh (they added it to the path 😉 booyah!)

 

Now you should have your drive all discovered and ready for fdisk!

 

Here’s the original link for this info: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/rescan-scsi-bus.html