Hi,

I am new to this forum; hopefully I am posting my questions in the right section/forum.
If not, I'll appreciate if you may provide me a link to the most appropriate url/page where to post what below.
(or feel free to move this post where more appropriate...)
Thanks in advance for your help and understanding...

Oh, Yes! I already searched this forum (after extensive googling for days) but I did not find satisfactory answers / solutions; so here I am...

NB: My questions are at the end of this post...

As to my problem:
I am preparing a new desktop computer; it will be a dual-boot 100% Linux only.
Aside hardware specs, this is my intended hard-disk concept:
- HD_1 - sdb - for Ubutu MATE (16.04.3)
- HD_2 - sdc - for OpenSUSE Leap 42.3
- HD_3 - sdd - for Data only
- HD_4 - sde - for Back-ups (and some temp-transit/spare space)
If you wonder why I did not start with sda, the reason is that my tower has a SATA dock I use for on-the-fly usage/experiments and is configured to be (if a drive is present) the very first one to boot.
(unless, if present, a floppy, a CD-DVD or a USB key - takes over, in that priority order, before other devices)

FYI
Providing your feedback/answers/suggestions, please take into account that:
1 - I am preparing a desktop production machine for Internet Marketing activities
2 - As such, it has to be rock-solid from every point of view
3 - The operating system must be prepared/configured as stable / unbreakable as possible
4 - Datawise, the partitioning and mainly the chosen file system must guaranty an absolute data integrity
5 - MoBo / BIOS is not-UEFI

In line of what above I have chosen:
- Ubutu MATE (16.04.3) for my own personal usage
- OpenSUSE Leap 42.3 for work/professional activities (mainly to use KDE PIM related modules)

My usual setup for Ubuntu based distros is this one:

sdb1 - BIOS-Grub
sdb2 - /boot
sdb3 - /swap
sdbn - some discrete partitions ( /usr - /var - /opt )
sdbx - / (root)
sdbx - /home (or possibly sdd1)
sdbx - /data (or possibly sdd3)
sdbx - (whatever and/or remainder of the disk)
All partitions formatted in ext4

As to OpenSUSE, the partition layout I got accepting all default settings for a test install was this one:

• Create root volume /dev/sdc1 (40.00 GiB) with btrfs
• Create volume /dev/sdc2 (1.78 TiB) for /home with xfs
• Create subvolume @/boot/grub2/1386-pc on device /dev/sdc1
• Create subvolume @/boot/grub2/x86_64-efi on device /dev/sdc1
• Create subvolume @/opt on device /dev/sdc1
• Create subvolume @/sry on device /dev/sdc1
• Create subvolume @Amp on device /dev/sdc1
• Create subvolume @/usr/local on device /dev/sdc1
• Create subvolume @/var/cache on device dev/sdc1
• Create subvolume @/var/crash on device /dev/sdc1
• Create subvolume @/var/lib/libvirt/images on device /dev/sdc1 with option "no copy on write"
• Create subvolume @/var/lib/machines on device /dev/sdc1
• Create subvolume @/var/lib/mailman on device dev/sdc1
• Create subvolume @/var/lib/mariadb on device /dev/sdc1 with option "no copy on write"
• Create subvolume @/var/lib/mysql on device /dev/sdc1 with option "no copy on write"
• Create subvolume @/var/lib/named on device /dev/sdc1
• Create subvolume @/var/lib/pgsql on device /dev/sdc1 with option "no copy on write"
• Create subvolume @/var/log on device /dev/sdc1
• Create subvolume @/var/opt on device /dev/sdc1
• Create subvolume @/var/spool on device /dev/sdc1
• Create subvolume @/var/tmp on device /dev/sdc1
• Use /dev/sdb3 as swap

Please notice that for the swap, OS Leap exploited the same /swap partition already existing on the Ubuntu hard-disk.
That's something I'd not like to do because I use hibernation pretty frequently (on both systems) so mixing two systems accessing the same swap partitions is a sure source of problems.

Now, the layout I have in mind for my planned install for OS 42.3 is this one:

sdc1 - BIOS-Grub
sdc2 - /boot
sdc3 - /swap (on the OpenSUSE hd - not the one created on the Ubuntu disk)
then - according to the original scheme/layout as proposed by the OS Leap install:
Create root volume /dev/sdc4 (40.00 GiB) with btrfs
• Create subvolume @/boot/grub2/1386-pc on device /dev/sdc4
• Create subvolume @/boot/grub2/x86_64-efi on device /dev/sdc4
• Create subvolume @/opt on device /dev/sdc4
• Create subvolume @/sry on device /dev/sdc4
• Create subvolume @Amp on device /dev/sdc4
• Create subvolume @/usr/local on device /dev/sdc4
• Create subvolume @/var/cache on device dev/sdc4
• Create subvolume @/var/crash on device /dev/sdc4
• Create subvolume @/var/lib/libvirt/images on device /dev/sdc4 with option "no copy on write"
• Create subvolume @/var/lib/machines on device /dev/sdc4
• Create subvolume @/var/lib/mailman on device dev/sdc4
• Create subvolume @/var/lib/mariadb on device /dev/sdc4 with option "no copy on write"
• Create subvolume @/var/lib/mysql on device /dev/sdc4 with option "no copy on write"
• Create subvolume @/var/lib/named on device /dev/sdc4
• Create subvolume @/var/lib/pgsql on device /dev/sdc4 with option "no copy on write"
• Create subvolume @/var/log on device /dev/sdc4
• Create subvolume @/var/opt on device /dev/sdc4
• Create subvolume @/var/spool on device /dev/sdc4
• Create subvolume @/var/tmp on device /dev/sdc4
plus:
sdc5 - /home (or possibly sdd2)
sdc6 - /data (or possibly sdd4)
sdc7 - (whatever and/or remainder of the disk)


Additional infos:
- I'll use GPT for all drives (with a not UEFI motherboard) preparing them with GParted Live
- My assumption is that all sdc4 subvolume as precognized by the openSUSE installer are OK
(Even if I am wondering about how safe is to use the btrfs for a production machine...)


All that said my questions are:
a) About Ubuntu, it's OK to use ext4 for all partitions or you'd suggest something different?
b) About xfs: is that fs really safer/better than ext4?
c) Would not be safer to use "no copy on write" also for subvolume @/var/lib/mailman on device dev/sdc4 ?
d) Same question/reasoning as above for /home /data and partitions on HD3/4 (for both Ubuntu and openSUSE)
e) I'd rather prefer to use Labels instead of UUID numbers - any easy way w/o messing with fstab and alike?
Last but not least:
On the whole, do you think that my planned setting is a reasonably sound one or you see some specific faults and/or other problematics drawbacks?


With your feedback (even if you are not answering any specific question) please feel free to provide any suggestion/comment/warning you might think helpful for what I am planning to do...
(even more if you see something wrong)

Thank You

If it were me, I would dodge the entire issue and use removable (USB, FireWire, Thunderbolt ...) disk devices for all such purposes. They're not expensive anymore, so just buy two!

Having a tower with an easy accessible docking for both 2.5" and 3.5" I already thought about such a possibility but that's only part of the problem.
My concern (mainly data-wise safety) is also to get an opinion (suggestions) about the partitioning schemes outlined in my post...