Attempt Arch Linux LVs reconfiguration in Post-installation phase

Following below is an attempt Arch Linux LVs reconfiguration in Post-installation phase.  Original LVs layout configuration  cannot be changed during archinstall active state. After archinstall finishes up we are going to switch to terminal session via "exit" option rather then reboot .

Exit to command line instead of immediate reboot and undertake following steps. Notice that root LV was increased in mounted state and procedure has succeeded.

Start reading snapshot  at : File system ext4 found on /dev/ArchinstallVg/root mounted at /mnt . . . .  

Filesystem at /dev/ArchinstallVg/root is mounted on /mnt : online resizing is required old_desc_blocks = 3 , new_desc_blocks = 7  .  .  .  .

resize2fs done

Extended filesystem ext4 on ArchinstallVg/root

Logical volume /dev/ArchinstallVg/root successfully resized

Now reboot. Compare `lsblk -f` report and content of /etc/fstab

Text report in details

[boris@ArchPlasma01 ~]$ uname -a
Linux ArchPlasma01 6.17.3-arch2-1 #1 SMP PREEMPT_DYNAMIC Fri, 17 Oct 2025 13:29:06 +0000 x86_64 GNU/Linux

[boris@ArchPlasma01 ~]$ lsblk -f
NAME                   FSTYPE      FSVER    LABEL UUID                                   FSAVAIL FSUSE% MOUNTPOINTS
sr0
zram0                  swap        1        zram0 58c4270c-2728-4f40-a25b-792f42131766                  [SWAP]
vda
├─vda1                 vfat        FAT32          790D-D015                               789.2M    23% /boot
├─vda2                 LVM2_member LVM2 001       V05b1U-SmrM-v3Se-71iL-1SIl-IrSJ-BGidJg
│ └─ArchinstallVg-root ext4        1.0            ac82c2a0-5350-467d-968b-f0fbadd9073f     43.1G    12% /
└─vda3                 LVM2_member LVM2 001       jxKMNF-tZZi-pBGO-Alcl-ggPD-1SjV-9lrnqx
  ├─ArchinstallVg-root ext4        1.0            ac82c2a0-5350-467d-968b-f0fbadd9073f     43.1G    12% /
  └─ArchinstallVg-home ext4        1.0            e5fca8c9-f501-4c2c-aa10-f831ad4f2cba     18.3G     0% /home

 [boris@ArchPlasma01 ~]$ cat /etc/fstab
# Static information about the filesystems.
# See fstab(5) for details.

# <file system> <dir> <type> <options> <dump> <pass>
# /dev/mapper/ArchinstallVg-root
UUID=ac82c2a0-5350-467d-968b-f0fbadd9073f       /               ext4            rw,relatime     0 1
# /dev/mapper/ArchinstallVg-home
UUID=e5fca8c9-f501-4c2c-aa10-f831ad4f2cba       /home           ext4            rw,relatime     0 2
# /dev/vda1
UUID=790D-D015 /boot  vfat    rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,utf8,errors=remount-ro   0 2

KDE Partition manager report