Archive for the ‘linux’ Category

Sending packets out of incoming interface

It is desirable, in some circumstances on a server with multiple NIC’s to send outgoing traffic on incoming interface. In order to do so the server has to have policy routing implemented. Let’s assume that the server is running CentOS 6 and that there are two network interfaces as follows: eth0 – 10.10.10.1/24 with gateway […]

Posted on September 3, 2017 at 10:39 by somedude · Permalink · Leave a comment
In: centos, linux, linux tips, networking, redhat, Uncategorized

Using whole disk for LVM during kickstart

I was kickstarting a machine that needed two disks. The requirement was that the second disk was to be used as whole for LVM. It seemed there was no way to do so, but apparently there is. The snippet below makes it happen. The key part is –onpart=sdb. part pv.02 –grow –size=1 –onpart=sdb volgroup vg_data […]

Posted on August 31, 2017 at 09:15 by somedude · Permalink · Leave a comment
In: centos, kickstart, linux, linux tips, redhat

Another take on Dynamic Volume Resize in RHEL 6

Being able to resize an LVM volume without reboot is quite handy. I had described one way here. This is a slightly different take on the same topic, this time on RHEL 6. I had resized /dev/sdb from 48GB to 140GB in vCenter. However, the operating system is still seeing the old size: [root@build ~]# […]

Posted on December 17, 2013 at 09:37 by somedude · Permalink · Leave a comment
In: centos, fibre channel, linux, linux tips, lvm2, san, storage

There is no screen to be resumed…

I was running a script on a server that took a while to complete. Since I did not want to lose any output I ran it inside a screen session. Of course, during the course of this, my SSH connection dropped and when I logged in again, and tried to reattached to the session I […]

Posted on November 15, 2013 at 08:56 by somedude · Permalink · Leave a comment
In: linux, linux tips, linux utilities, screen, shell

Hung Linux system: Now what?

Finally, I had remembered to try out Magic SysRq key in real life. One of the XenServer hosts decided to refuse to reboot and hung during shutdown. Magic SysRq is really a keyboard combo that allows user to force kernel to perform certain function, even though machine is unresponsive. In my case I needed to […]

Posted on October 30, 2013 at 09:04 by somedude · Permalink · Leave a comment
In: centos, linux, linux tips, redhat