How to run fsck on a Logical Volume in Linux.
I recently had a problem on my laptop running Fedora 11 where my X session just totally froze when trying to bring the laptop back from a hibernate state. Outside of the occasional issues coming out of hibernate (usually X not restoring) I'd say Fedora 11 has been pretty solid. This particular time, my X session restored but everything locked up. I tried switching to another virtual terminal to log in and kill GDM but some sort of inode error just streamed down the console. My only option was a hard reboot and after that I couldn't boot Fedora with any kernel. To fix my problem I booted off the Fedora install CD into rescue mode without mounting / . I then performed the following:
# lvm pvscan # lvm vgscan # lvm lvchange -ay /dev/VolGroup00/LogVol_home # lvm lvscan # fsck -yfv /dev/VolGroup00/LogVol_home
Connect to Cisco routers using screen
screen is a Linux utility that I use to connect to the console on Cisco routers. If your router is plugged in to a serial port on a Linux box, you can use the following command to connect to it:
[dacaprice@FedoraBox ~]$ screen /dev/ttyS0
Changing sdiff column width in Linux
I use sdiff pretty often to do a side-by-side comparison of config files on my Linux box. The thing that annoys me the most is the default column width; often whatever it is I am comparing, gets cut short because the width is too narrow. I like use the -w ColumnWidth to set a wider width and the -s to supress any common lines.
[dacaprice@fedora]$ sdiff -s -w 150 file1 file2
Nov. 5, 1955: A Flux of Genius | This Day In Tech | Wired.com
Dr. Emmett Lathrop Brown is known for being a member (unverified) of the Manhattan Project, a physics professor at Hill Valley University, and a talented entrepreneur and handyman. But it’s his contribution to the field of temporal physics for which he is best remembered.
According to archival footage, Brown was standing on his toilet seat on the evening of Nov. 5, 1955, attempting to hang a clock in his bathroom, when he slipped and slammed his head on the side of the sink. Upon regaining consciousness Brown reported having “a revelation, a picture, a picture in my head.” A picture which he crudely scrawled down on a piece of paper and subsequently spent 30 years of his life and family fortune to build.
via Nov. 5, 1955: A Flux of Genius | This Day In Tech | Wired.com.
Switching between AT&T 3G and 2G networks
To battle a reception problem (can't send/receive calls or texts) I'm having with AT&T's 3G network, I had to force my iPhone to connect to their 2G (Edge) network while AT&T works out their local tower problems. To do that I touched:
- Settings
- General
- Network
- Enable 3G (turned off)
Lesson learned: If you're having reception problems and power cycling your phone doesn't work, try turning off the 3G before calling AT&T to see if you can connect to the 2G network. Normally, if 3G isn't available, the iPhone should default to 2G. In my case, the problem seemed to be intermittent so my phone was bouncing between both networks, unable to actually connect to either.