Posts Tagged ‘bootable media’

Quick items about repackaging Linux ISO

Thursday, October 28th, 2021

There are two topics I would like to describe here, for later reference (by myself, of course. This blog is my extended memory). The first is about how to create a bootable ISO out of RHEL extracted ISO, and the other is about how to download only specific update, or make your own RHEL updates on-prem mirror.

Bootable ISO

From within the (modified?) extracted ISO of RHEL7.x (in this example. Match settings to your needs), in order to be able to boot the ISO both in legacy and uEFI BIOS – you can run this command:

genisoimage -J -T -o ../RHEL-7.9_`date +%F_%H-%M-%S`.iso -b isolinux/isolinux.bin -J -R -l -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -eltorito-alt-boot -e images/efiboot.img -no-emul-boot -graft-points -V "RHEL-7.9 Server.x86_64" .

Create a local mirror of RHEL packages

This is a long one, so I will leave only a link to RedHat’s article about it. I hope you have access (you should, if you want to mirror their repository). If you don’t – it’s easy and free to open an account (even without subscribed systems), so you’ll have access to their articles. The article can be found here

Dell PowerEdge 1800 and Linux – Part 1

Tuesday, September 27th, 2005

As part of my voluntary actions, I manage and support Israeli Amateur Radio Committee Internet server. This machine is an old poor machine, custom made about 5-7 years ago, containing Pentium2 300MHz, and 256MB RAM. It serves few hundreds of users, and you can guess for yourself how slow and miserable this machine is.

After
long wait, the committee has decided to purchase a new server. This server, Dell PE 1800, has landed in my own personal lab just two days ago. It’s a nice machine, cheap, considering its abilities, and it’s waiting just to be installed. Or so it was, just up to now.

Mind you that brand PC servers containing more than one CPU can cost around
3K$ and above. This baby has come with a minimal, yet scalable setup, containing only one CPU out of two, 1GB RAM, our of 8GB possible max, and two SCSI HotSwap HDDs, using 2 out of 6 slots. Nice machine. And it was cheap too. Couldn’t complain about it.

At first, I’ve tried using Dell’s CDs. The "Server Setup" CD is supposed to help me prepare the machine to OS installation, either it be Windows, Linux, Novell, etc. I’ve tried using it, preparing it to a new Centos install, when I’ve noticed it didn’t partition quite as I’ve expected. Well, the "Server Setup" tool has decided I would not use Mirrors, and that I would not use LVM, but would use a predefined permanent setup, and that’s all. This machine did not come with a RAID controller, so I’ve had to configure Software RAID. What better time is there than during the install? Dell’s people think otherwise, so I’ve had to boot into a bootable media of Centos 4.1 (my whole installation tree resides on NFS share). The installation was smooth, and worked just like expected. Fast, sleek, smooth. All I’ve ever expected out of Linux installation on a server class PC. Just like it should have been.

I’ve partitioned the system using the following guidelines:

1) Software mirror Raid /dev/md0, containing /boot (150MB)

2) Two stand alone SWAP partitions, 1GB each, one on each HDD. I do not need mirror for the SWAP.

3) Software mirror Raid /dev/md1, containing LVM, expanding all over what’s left of the disk.

4) Logical Volumes "rootvol" (5GB) holding / and "varvol" (6GB) holding /var. Both can be expanded, so I don’t need to worry now about their final sizes.

As said, the installation went great. However, I was not able to boot the system… I just got each time to a hidden maintenance system partition, and it seems my GRUB failed to install itself. Darn.

I’ve booted into rescue mode, and tried to install GRUB manually. Failed. I think (and it’s not the first time I’ve had such problems with GRUB) GRUB is not as good as everyone say it is. It can’t boot into software mirror, and it means it’s not ready for production, as far as I are.

I’ve used YUM to download and install Lilo, and managed easily to convert /etc/lilo.conf.anaconda to
the correct file for Lilo (/etc/lilo.conf), and to run it. Worked great, and the system was able to boot.