Inserting a disk

Did the same as for merlin disk. The attached file reports on how the disk was configured with fdisk. One thing to notice is that dos disklabel type was set.

To use partprobe, package parted must be installed.

sudo apt-get install parted

After the whole procedure (including xfs_grow), this is the disk layout as reported by fdisk:

Disk /dev/sda: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Disk model: ST4000VN006-3CW1
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: EE02513B-3BCE-704C-AA8E-F32E63FDC0E6

Device     Start        End    Sectors  Size Type
/dev/sda1   2048 7814037134 7814035087  3.7T Linux filesystem

and df -h:

/dev/sda1       3.7T   28G  3.7T   1% /data_hdd

Adding external disk for cold storage

1. Find inserted device. Usb will create /dev/sdb or a similar entry point for inserted USB drives.

   $ sudo dmesg
   
   

2. Check partitioning. More likely than not, a partition was already created, but it might be
   a less resilient MS type and format. The second command allows to modify partition, to change
   follow instructions, but typically it should be t followed by 20 for Linux filesystem and
   a w to write changes

   $ sudo fdisk -l /dev/sdb
   $ sudo fdisk /dev/sdb
   
   

3. Reformat to linux resilient ext4 format for storage

   $ sudo mkfs -t ext4 /dev/sdb1
   Superblock backups stored on blocks:
       32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
       4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
       102400000, 214990848
   $ sudo lsblk -f /dev/sdb1
   NAME FSTYPE LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINT
   sdb1 ext4         2fde7150-8c3a-444d-b715-a3136e9da3c3
   $ sudo mkdir /mnt/backup
   $ sudo mount /dev/sdb1 /mnt/backup/