How to install Docker in Red Hat 8.0

[Denzil]

Good day to you,

may you be good  enough to walk me though for a Docket installation.

Kind Regards

[Travis]

@Denzil -

You never answered the question on what you are trying to do, why you are doing it, or what you hope to get out of this setup. As mentioned, the distros run different tools, so this could confuse learning. Also, I know that various Ubuntu flavors including the base all have a LiveISO/LiveCD so you can run and use those completely without installing to the disk.

The easy questions out of the way ...

• LVM is not a requirement, but it would help separate filesystems for each distribution and give a "pool" of storage by having a VG with different LVs for use in that version of Linux. Alternatively, you could just have the boot filesystem and root with everything and not have separate partitions, everything would be mounted to "/"
• SWAP - this partition can be reused across the various distributions as it is where RAM gets swapped out to the disk. 512MB isn't a very large SWAP and it is generally recommended to set SWAP size based on RAM.
• There is no script that will do everything you want. Kickstart scripts can be created for a single Linux installation, but you won't find a script that will partition the disk for multiple OSes and install the multiple OSes.
• EFI Boot menu - This is a menu for UEFI booting your system. Boot files and entries are on the EFI Boot partition and read by the system UEFI (where BIOS) is. The EFI boot menu can have multiple entries and only one is default. This is why you need to hit F11 to see the boot menu and select Red Hat as Debian must be the default entry.

There isn't anything else easier that you can do. You need to figure out what you are doing with the systems and size the partitions appropriately. Again, a minimal sized system would be 10GB-20GB, but if it is used, the filesystem could fill up quickly especially when using Internet and downloading. Our Red Hat courses have a graphical workstation which is typically 20GB in size for the entire disk and some of the most advanced courses we have at 40GB in size for the workstation VM. This is fine for our purposes, but if I am doing a bunch of container images or need to download an ISO for example, one ISO could take 10GB of the available space or be larger that what is available on the disk, so all considerations.

My suggestion would be to stick with one "flavor" of Linux and learn it well and play around with installations because that is the only way you can move forward.

[Denzil]

Good day to you Travis,

My apologies there.

Why am I doing this? (1)  In my earlier blog with you, which regards my Redhat password; someone taught me how to install all three flavors over a dozen online, live sessions. The notes I took, got misplaced, and I like to do it by myself, as a learning experience. (2) In your last year's explanations, you educated me, what is what and how it helps with the Cloud. (3) I am about to go for Docker et el, and before that I am keen to know all three flavours of Linux. 

As regards to, " The EFI boot menu can have multiple entries and only one is default. This is why you need to hit F11 to see the boot menu and select Red Hat as Debian must be the default entry."  In my case I see RedHat 8.10 after pressing F11. It boots perfectly.

The person who guided me through, guided me through in such a way, thet after the final installation of Ubuntu, then after the reboot, I get a {GRUB) Menu, from which I can easily select the Linux flavour I need.

Kind Regards,

Denzil

[Travis]

@Denzil -

Again, your earlier installation can't be compared to how things work today. Your old system had BIOS partitioning and was limited in the amout of PRIMARY partions it could have so you had extended partitions. You were also using MSDOS/BIOS style partitioning and booting which didn't have EFI. So those are huge differences in how things were when you first set things up and how they are now. I imagine you did have GRUB, but some of the first multi-boot systems I had used LILO as the boot manager which again had entries for all the OSes.

In terms of learning for the cloud, I would stick to just RHEL and Ubuntu as those are the two images you are most likely to encounter. Remember, Ubuntu is a derivative of Debian, so unless you have an exact use-case you are better sticking with two. Also, if it is to learn containers, keep in mind, dealing with a container will be very different than managing a physical OS and all the components around it.

If you are going to have multiple OSes on the system, Ubuntu is probably your easiest choice and best for the primary bootloader as it can best detect other kernels. Each distribution will have its own GRUB on the EFI partition and EFI can only boot one. What you will need to do after things are installed, is boot to the primary, and in my example I was suggesting Ubuntu. Then you will need to generate a new GRUB menu. Ideally, this can be automatic with the OS_PROBER turned on, it should find the other EFI entries to add to the GRUB menu.

One other thing to keep in mind is formatting of the filesystems. RHEL8 and up you are using XFS by default, but some of the other distros might not have it. For best compatbility, you might want to use something like EXT4. I've given you a starting partitioning scheme below. This would leave a bunch of unpartitioned space. Theoretically, you could have a "DATA" partition that could be then shared and mounted across all your Linux installations. It also leaves room if you choose to install additional distributions.

Partition	Size	Type	Mount Point	Purpose
sda1	1024MB	FAT32	/boot/efi	Shared EFI Bootloader files
sda2	100GB	ext4	/ (RHEL)	RHEL System Files
sda3	100GB	ext4	/ (Debian)	Debian System Files
sda4	100GB	ext4	/ (Ubuntu)	Ubuntu System Files
sda5	8GB	swap	swap	Shared Virtual Memory

I was also looking for a nice article for SWAP, but found a Youtube instead:

https://www.youtube.com/watch?v=W5FlEioA0iE&t=253s

Some references of additional information:

https://www.zdnet.com/article/hands-on-linux-uefi-multi-boot-my-way/

https://medium.com/@manujarvinen/setting-up-a-multi-boot-of-5-linux-distributions-ca1fcf8d502 (Shows 5 versions of Linux being installed)

[Denzil]

Hello Travis,

Highly appreciate for your quck, technical and detailed response.

I shall respose to you in the morning.

Kind Regards,

Denzil

[Denzil]

Hello  Sunnykumar,

Thank you for that, but what might be the exact values which shall go into RHEL 8.10, Debian, and Ubantu? 

I have used the manual partitions,  VIA Standard, not LVM

Kind Regards,

Denzil