Dtcubed Software Notes

Let "A" and "B" be Linux hosts.
Let B be the Linux host we want to grab the serial (console) output from.

1) Run a null modem cable between A and B.
2) Added "console=ttyS0,9600" to the boot line of B.
3) cu -l /dev/ttyS0 | tee console-out-from-b.txt from A. (could use minicom too)
4) Reboot B.
5) Console output from B should be visible on A.

Friday, July 31, 2009

IB Fabric: Manipulating HSM Autostart

# Stop all HSMs
cmdall "service qlogic_fm stop"

# Keep Them Off
cmdall "chkconfig qlogic_fm off"

# Turn an HSM on for a particular host. Keep it on for reboot.
# On the chkconfig command, the runlevels are specified in
# the init script itself. So, you don't have to specify
# "--level 235" for example.
cmdall -h st146 "service qlogic_fm start"
cmdall -h st146 "chkconfig qlogic_fm reset"

Online Git Book

Online git book here.

http://help.github.com/

Another one:

http://book.git-scm.com/

Good Git conceptual link:

Gitready Link

Git Architecture Link

Friday, June 19, 2009

Interesting Boot Loader

Unetbootin

http://unetbootin.sourceforge.net/

Monday, February 23, 2009

Redirect Console Messages To RS-232 On RHEL 5.2

1) Add the following lines to /etc/inittab

s0:2345:respawn:/sbin/agetty -L -f /etc/issueserial 9600 ttyS0 vt100

s1:2345:respawn:/sbin/agetty -L -f /etc/issueserial 9600 ttyS1 vt100

2) Add the following lines to /etc/securetty

ttyS0

ttyS1

3) Add the following directive to the GRUB boot line for the kernel:

console=ttyS1,9600

Wednesday, February 04, 2009

Watching Ethernet Interface(s): mii-tool

# mii-tool -v eth0
eth0: negotiated 100baseTx-FD flow-control, link ok
product info: vendor 00:08:18, model 24 rev 0
basic mode: autonegotiation enabled
basic status: autonegotiation complete, link ok
capabilities: 1000baseT-HD 1000baseT-FD 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD
advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control
link partner: 1000baseT-HD 1000baseT-FD 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control

# mii-tool -w -v eth0
16:31:05 eth0: negotiated 100baseTx-FD flow-control, link ok

Sunday, November 23, 2008

High Level Overview: Duplicating Linux Multi-Boot Systems

Assumptions:
-- 2 drives, /dev/sda and /dev/sdb, roughly 160GB each.
-- Each node has identical h/w, including drives.
-- Partitions:
sda1(/boot), sda2(swap), sda3(OS #1), sda4(extended, containing 5-9), sda5(OS #2), sda6(OS #3), sda7(OS #4), sda8(OS #5), sda9(OS #6), sdb1(OS #7), sdb2(OS #8), sdb3(OS #9), sdb4(extended, containing 5-9), sdb5(OS #10), sdb6(OS #11), sdb7(OS #12), sdb8(OS #13), sdb9(OS #14)
-- All partitions are compatible with the partimage utility. EXT3 is the choice here.
-- GRUB installed into MBR and pulling its OS boot options (grub.conf/menu.lst) from sda1

Backup:
-- Boot Knoppix 5.1.1
-- Mount desired NFS share
-- Use sfdisk to capture the partitioning information for sda and sdb
sfdisk -d /dev/sda > /NFS/dev-sda-sfdisk-info.txt
sfdisk -d /dev/sdb > /NFS/dev-sdb-sfdisk-info.txt
-- Change into the desired NFS sub-directory
-- Use partimage to image all of the partitions. Here is the idea for sda1.
/usr/sbin/partimage --batch -z1 -o -d save /dev/sda1 ./dev-sda1-image

Restore/Duplication:
-- Boot Knoppix 5.1.1

-- If Knoppix is using a pre-existing swap partition, disable with "swapoff -v "
-- Mount desired NFS share
-- Use sfdisk to write out the partitioning information for sda and sdb
sfdisk /dev/sda < /NFS/dev-sda-sfdisk-info.txt
sfdisk /dev/sdb < /NFS/dev-sdb-sfdisk-info.txt
-- Use sfdisk to verify the partitioning information for sda and sdb
sfdisk -l -V /dev/sda
sfdisk -l -V /dev/sdb
-- Change into the desired NFS sub-directory
-- Use partimage to write out all of the partitions. Here is the idea for sda1.
/usr/sbin/partimage --batch restore /dev/sda1 ./dev-sda1-image.000
-- Use the GRUB shell to write out the MBR and insist, for our example, that GRUB pulls its OS boot options (grub.conf/menu.lst) from sda1.
grub
root (hd0,0)
setup (hd0)
quit
-- Reboot and enjoy your multi-boot Linux system.

NOTE: See this LINK for more GRUB info. It's pretty darn good.

Thursday, October 30, 2008

TestDisk Utility

Try TestDisk:

http://www.cgsecurity.org/wiki/TestDisk

Friday, October 24, 2008

InfiniBand Testing: Suggested Partitioning for Linux Hosts

Here are my suggestions for partitioning Linux host lab systems for InfiniBand OFED testing:

/boot (~100 MB)
swap (usually 2x RAM, so 4096 MB if 2GB of RAM)
/ (install rest of OS)

Other notes:
1 - use the GRUB bootloader; install into Master Boot Record (MBR)
2 - use EXT3 filesystems for compatibility with the Partimage utility
3 - when gathering data for later restoration, remember to capture the MBR.

Wednesday, September 24, 2008

One Linux Dual-Boot Technique (Pretty Specific)

Here is a basic write-up of the technique that I used to achieve
dual-booting between SuSe and RHEL operating systems.

Assumptions:
1) /dev/sda (SuSe, active GRUB boot loader)
2) /dev/sdb (RHEL)
3) The RHEL os had previously been installed/booted with GRUB in /dev/sda slot)
4) The RHEL /boot partition is now here: /dev/sdb3

Basic Technique:
1) Make a backup of the SuSe GRUB configuration file.
cd /boot/grub
cp menu.lst menu.lst-ORG (this file used to be called "grub.conf")

2) Mount the previously used RHEL /boot partition.
mkdir /mnt/rhel-boot
mount /dev/sdb3 /mnt/rhel-boot

3) Create a new, unified GRUB configuration file by pulling the necessary
RHEL boot information from the /mnt/rhel-boot/grub/menu.lst file and
add it to the end of the /boot/grub/menu.lst file associated with the
SuSe rendition of the GRUB boot loader.

When I did this, I just had to change the "root" line from "(hd0,2)"
to "(hd1,2)".

4) Unmount the RHEL /boot partition.
cd /
umount /mnt/rhel-boot

5) Reboot, and enjoy your dual-boot machine.
init 6

Tuesday, June 29, 2010

Thursday, June 10, 2010

Wednesday, June 09, 2010

Thursday, May 20, 2010

Tuesday, May 18, 2010

Monday, May 17, 2010

Friday, April 30, 2010

Tuesday, April 06, 2010

Thursday, March 25, 2010

Wednesday, January 13, 2010