Unclear instructions for creating fstab from /proc/mounts

[o-alquimista]

In installation/chroot/configure fstab you are supposed to overwrite /etc/fstab with the contents of /proc/mounts:

[xchroot /mnt] # cp /proc/mounts /etc/fstab

Then it says:

Remove lines in /etc/fstab that refer to proc, sys, devtmpfs and pts

OK, I look for lines that start with proc, sys, devtmpfs or pts, and erase them. But what about the remaining dozens of mounts, should I keep them all?

This is what /proc/mounts looks like to me:

/dev/mapper/voidroot / ext4 rw,relatime 0 0
/dev/mapper/voidhome /home ext4 rw,relatime 0 0
/dev/mapper/voidvar /var ext4 rw,relatime 0 0
/dev/mapper/voidtmp /tmp ext4 rw,relatime 0 0
/dev/nvme0n1p2 /boot ext4 rw,relatime 0 0
/dev/nvme0n1p1 /boot/efi vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev,noexec,inode64 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
securityfs /sys/kernel/security securityfs rw,relatime 0 0
efivarfs /sys/firmware/efi/efivars efivarfs rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup tmpfs rw,relatime,mode=755,inode64 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset 0 0
cgroup /sys/fs/cgroup/cpu cgroup rw,relatime,cpu 0 0
cgroup /sys/fs/cgroup/cpuacct cgroup rw,relatime,cpuacct 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,relatime,blkio 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,relatime,memory 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,relatime,freezer 0 0
cgroup /sys/fs/cgroup/net_cls cgroup rw,relatime,net_cls 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,relatime,perf_event 0 0
cgroup /sys/fs/cgroup/net_prio cgroup rw,relatime,net_prio 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,relatime,hugetlb 0 0
cgroup /sys/fs/cgroup/pids cgroup rw,relatime,pids 0 0
cgroup /sys/fs/cgroup/misc cgroup rw,relatime,misc 0 0
cgroup2 /sys/fs/cgroup/unified cgroup2 rw,relatime,nsdelegate 0 0
cgroup /sys/fs/cgroup/elogind cgroup rw,relatime,name=elogind 0 0
LiveOS_rootfs /etc/resolv.conf overlay rw,relatime,lowerdir=/run/rootfsbase,upperdir=/run/overlayfs,workdir=/run/ovlwork 0 0

For example, there are multiple cgroup lines, and one LiveOS_rootfs line. I never had to add anything like this to fstab on other operating systems. This doesn't look right to me.

[o-alquimista]

I've finished the encrypted installation for the first time, and now I suppose I only need to keep the /dev/mapper and /dev/nvme lines, and also the /tmp tmpfs directory, which is properly documented.

The resulting /etc/fstab is this:

tmpfs           /tmp    tmpfs   defaults,nosuid,nodev   0       0
/dev/mapper/voidroot / ext4 rw,relatime 0 0
/dev/mapper/voidhome /home ext4 rw,relatime 0 0
/dev/mapper/voidvar /var ext4 rw,relatime 0 0
/dev/mapper/voidtmp /tmp ext4 rw,relatime 0 0
/dev/nvme0n1p2 /boot ext4 rw,relatime 0 0
/dev/nvme0n1p1 /boot/efi vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

Can we improve that part of the documentation, for extra clarity?

This part:

Remove lines in /etc/fstab that refer to proc, sys, devtmpfs and pts

Becomes this (my suggestion):

Remove lines in /etc/fstab that refer to pseudo-devices (or virtual filesystems).

[classabbyamp]

that suggestion seems less clear because it refers to the things to remove in more abstract terms.

it would probably be better to write a script like arch's/chimera's fstab generators and document that instead