[SOLVED] Partition schemes

I would like some advice on partitioning.
Set up. Mother Board ASUS Prime Z390M-PLUS
32 GB RAM
1 Samsung 250 GB SSD M2 format (second one can be added)
2 WD 2 TB Hard drives.

Intended OS Fedora 31
What I was planning was a partition scheme as follows
on the SSD have,
/Boot
/
swap

Then have the two Hard drives configured as a RAID with
/home
/var
/temp
and a number of data partitions like Videos, Music , Papers, Data etc.

The Raid would be set as per the partition application that comes with the fedora install.

Can such an arrangement be done?
What do I need to set the SSD partitions to LVM or standard partition
What about the secure boot?

An alternative arrangement would be to put the two Samsung SSD in and set them as a raid configuration as well as the two hard drives, so there would be two Raid arrays.
In this configuration I envisage he set up as;
Raid array 1
/boot
/
swap
/var
/temp

and on Raid 2 would be
/home
/Video
/Music
etc.

Having said that however I would prefer to have /var and /temp on the Raid 2 array just because I have read that SSD’s can have some issues with a lot of reads and writes.

Complicating factors I do not fully understand
1. Is it better to set the Raid 1 Array up using the Intel Raid configuration that comes on the mother Board. In other words activate the two SSD M2 units as RST active in the BIOS. What else do I need to change in the BIOS and are there any implications are there for Secure Boot or BIOS Boot (basically nothing in the motherboard manual).

If the Raid-1 array is set using the mother board what do I need to enter the /boot /, swap and other partitions, if I put them on the Raid 1 array as using the Fedora partitioning app. LVM, Standard partition or ?

Have not found it easy to find definitive partition set up information wit Raid arrays and various combinations of single and Raid arrays.

My thoughts as to having a non raid for the operating system and a raid for the data like /home etc is that the OS can be replaced but the data can not so having a Raid with a copy of the data on it gives some additional back up to the main backup.

As an aside, in a previous set up I found the /var partition got full. It was 10 GB, in size as seen in some recommended partition schemes, However I found that there was not sufficient space for doing an update especially if one has flatpak applications installed. In the partition scheme above I am looking at setting the /var partition to 25 GB.

Finally what are the thoughts on having /var and /temp partitions on an SSD. As I indicated above have read that because /var and /temp have a high number and read write cycles it is better to have there partitions on a hard drive. Something to do with the way an SSD deletes and writes information.

Anyway be interested in the thought on these matters. Thanks

Way too complicated for my liking, but ...
- your concerns re the SSD are largely historical. Don't worry about it.
- use the SSD for what you need fast response - so /boot and the root is my choice
- swap ? ... hmmm; it's slow so who cares; stick it on the hard disks.
- use LVM to handle the hard disks, including the RAID (i.e. not mdadm) - in essence it doesn't matter if /var runs out of space if you ensure you don't totally allocate the pv/vg.
- dracut should look after all the loose ends for the initrd.

I'm guessing anaconda will set up the RAID properly - as I intimated I wouldn't set it up that way, but you'd have to think it's common enough to be supported "out-of-the-box".

Originally Posted by GRS63 Is it better to set the Raid 1 Array up using the Intel Raid configuration that comes on the mother Board. In other words activate the two SSD M2 units as RST active in the BIOS.

This is BIOS RAID. It works, until you have a motherboard failure and cannot replace it with an exact duplicate. If you cannot, everything on the RAID that is not fully backed up is usually history. OTOH, using software RAID set up by Anaconda, the RAID is mobile among various hardware and GNU/Linux operating systems. I've been satisfactorily using software RAID on GNU/Linux for nearly a decade.

what are the thoughts on having /var and /temp partitions on an SSD

/tmp is normally configured by Anaconda as tmpfs (in RAM). Unless you are sure of what you are doing, and why, you shouldn't be specifying a separate partition for /tmp.

I don't use LVM. I have separate MD devices on my rotating rust disks for /home, /srv, big data files (videos, isos), other shared files, and /usr/local. On my 120 GB SSD I have only five operating systems, swap and booting.

1. Cut two small partitions from big WDs, make them /boot running on /dev/md0.

2. Make the rest space as PV for LVM rootvg.
Every LV that you will create, create it with LVM mirroring option.

3. Add SSD to LVM as cache device for LVM
Look for instructions googling "lvm cache ssd"

It is possible even not to build /boot using grub abilities.
You can see example here: Redundant disks without MDRAID

Thanks for the advice. I have gone for the operating system on the SSD and the other stuff on the hard drives,set up as a software raid. Seems to give me something I can work with.
It is very clear there is no sort of optimum scheme, as there are so many ways of doing it, Even getting data on the size to make the partitions is all over the place when reading the various articles on the Web.
Anyway I have a system working. Thanks for the input

Originally Posted by GRS63 It is very clear there is no sort of optimum scheme, as there are so many ways of doing it, Even getting data on the size to make the partitions is all over the place when reading the various articles on the Web.

That's Linux for you - it's all about choice. Sometimes too much, but it's out there somewhere. And yes there will be an optimum choice, but it will be for your situation on your equipment. Only you can determine that - we can merely provide suggestions.