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+
+# STATE AFTER REPLACEMENT:
+
+DISK BAY 3: Intel PHYF209300LX3P8EGN
+DISK BAY 2: Intel PHYF209106Y93P8EGN
+DISK BAY 1: Inland 22062712800355
+DISK BAY 0: Inland 24010919300014
+
+root@rathouse:~# lsblk
+NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
+sda 8:0 0 111.8G 0 disk
+├─sda1 8:1 0 485M 0 part
+└─sda2 8:2 0 93.1G 0 part
+ └─md0 9:0 0 93.1G 0 raid1 /
+sdb 8:16 0 119.2G 0 disk
+├─sdb1 8:17 0 487M 0 part /boot/efi
+├─sdb2 8:18 0 93.1G 0 part
+│ └─md0 9:0 0 93.1G 0 raid1 /
+└─sdb3 8:19 0 7.5G 0 part
+sdc 8:32 0 3.5T 0 disk
+└─sdc1 8:33 0 3.4T 0 part
+ └─md127 9:127 0 3.4T 0 raid10 /tank
+sdd 8:48 0 3.5T 0 disk
+└─sdd1 8:49 0 3.4T 0 part
+ └─md127 9:127 0 3.4T 0 raid10 /tank
+
+root@rathouse:~# smartctl -a /dev/sda
+smartctl 7.3 2022-02-28 r5338 [x86_64-linux-6.1.0-22-amd64] (local build)
+Copyright (C) 2002-22, Bruce Allen, Christian Franke, www.smartmontools.org
+
+=== START OF INFORMATION SECTION ===
+Model Family: Phison Driven OEM SSDs
+Device Model: SATA SSD
+Serial Number: 24010919300014
+....
+....
+
+
+#################################
+
+Making sure the EFI / bootloader should be all good:
+
+# look at current EFI boot settings
+efibootmgr -v
+
+# lets say the currently selected boot device is the one that has to be removed.
+# in order to run grub-install on the new disk, we have to first unmount the current EFI boot partition
+umount /boot/efi
+
+
+mount /dev/sdb1 /boot/efi
+
+# now that the correct EFI boot partition is mounted at /boot/efi, we can run grub-install
+grub-install /dev/sdb
+
+# check our work. Note that this REPLACES the previous boot option instead of adding a new one.
+efibootmgr -v
+
+# further checking our work:
+ls /boot/efi
+ls /boot/efi/EFI
+
+# for info about how to add an additional boot entry, see
+# https://www.linuxbabe.com/command-line/how-to-use-linux-efibootmgr-examples#add-uefi-boot-entry
+
+
+##################################
+
+# remove the failed disk from the mdraid array
+
+mdadm --manage /dev/md0 --fail /dev/sdb2
+mdadm --manage /dev/md0 --remove /dev/sdb2
+
+# different useful ways to list disks
+fdisk -l
+blkid -o list
+lsblk
+
+
+# get sector sizes for the partion you need to make
+fdisk -l
+
+# partition the new disk.
+
+parted /dev/sda mklabel gpt
+parted -a opt /dev/sda mkpart primary fat32 2048s 995327s
+parted -a opt /dev/sda mkpart primary ext4 995328s 196306943s
+
+
+# add new disk to mdraid array
+mdadm /dev/md0 --add /dev/sda2
+
+# watch progress bar
+
+cat /proc/mdstat
+cat /proc/mdstat
+cat /proc/mdstat
+
+
+
+
+
+