CentOS 8.x parted resize existing partition

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CentOS 8.x parted resize existing partition

If a partition is created using LVM it can be resized by CentOS 7.x Create LVM partition on new disk However, if a partition is not created via LVM then resizing it requires following steps:

1. If the underlying storage is iSCSI / FC and the storage disks needs resizing then resize disk at storage level
2. After disk is resized at storage level need to reboot the machine for new disk size to be visible
3. After reboot validate that updated size is visible using 'multipath -ll', if multipath is in use:

   [root@example ~]# multipath -ll
   san01 (3600601606d104c0046c5e75c2ed54946) dm-2 DGC     ,VRAID
   size=510G features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
   |-+- policy='service-time 0' prio=50 status=active
   | `- 16:0:0:0 sdc     8:32  active ready running
   `-+- policy='service-time 0' prio=10 status=enabled
   `- 15:0:0:0 sdb     8:16  active ready running

   After resize and reboot the new size increase from old 510GB to 1.0TB

   [root@example ~]# multipath -ll
   san01 (3600601606d104c0046c5e75c2ed54946) dm-2 DGC     ,VRAID
   size=1.0T features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
   |-+- policy='service-time 0' prio=50 status=active
   | `- 16:0:0:0 sdc     8:32  active ready running
   `-+- policy='service-time 0' prio=10 status=enabled
   `- 15:0:0:0 sdb     8:16  active ready running

4. Check increased disk size using "fdisk -l". In case of multipath, the increased size should reflect for all device names (eg /dev/sdb, /dev/sdc) in above example.
5. Umount the partition(s) such as

   umount /dev/mapper/san01p1

6. Check the filesystem for errors using

   fsck -f /dev/mapper/san01p1

7. Check partition table using 'parted <device-name> print' command and if prompted to fix gpt issues, choose to fix. Example:

   [root@example ~]# parted /dev/mapper/san01 print
   Error: The backup GPT table is not at the end of the disk, as it should be.  This might mean that another operating system believes the disk is smaller.  Fix, by moving
   the backup to the end (and removing the old backup)?
   Fix/Ignore/Cancel? Fix
   Warning: Not all of the space available to /dev/mapper/san01 appears to be used, you can fix the GPT to use all of the space (an extra 1098907648 blocks) or continue
   with the current setting?
   Fix/Ignore? Fix
   Model: Linux device-mapper (multipath) (dm)
   Disk /dev/mapper/san01: 1100GB
   Sector size (logical/physical): 512B/512B
   Partition Table: gpt
   Disk Flags:
   
   Number  Start   End    Size   File system  Name     Flags
   1      4194kB  532GB  531GB  ext4         primary

8. Resize the underlying partition using parted command 'parted /dev/mapper/san01', where san01 is the multipath device
   1. After starting parted change unit to GB using 'unit GB'
   2. Get free space details using 'print free'. Example output

      (parted) print free
      Model: Linux device-mapper (multipath) (dm)
      Disk /dev/mapper/san01: 1100GB
      Sector size (logical/physical): 512B/512B
      Partition Table: gpt
      Disk Flags:
      
      Number  Start   End     Size    File system  Name     Flags
      0.00GB  0.00GB  0.00GB  Free Space
      1      0.00GB  532GB   531GB   ext4         primary
      532GB   1100GB  568GB   Free Space
      

   3. Resize existing partition using 'resizepart'. Then enter partition number (eg 1 in above example) and desired size. Example

      (parted) resizepart
      Partition number? 1
      End?  [532GB]? 1070GB
      (parted) print
      Model: Linux device-mapper (multipath) (dm)
      Disk /dev/mapper/san01: 1100GB
      Sector size (logical/physical): 512B/512B
      Partition Table: gpt
      Disk Flags:
      
      Number  Start   End     Size    File system  Name     Flags
      1      0.00GB  1070GB  1070GB  ext4         primary

      Here intentionally left 30GB space at end from 1070GB to 1100GB

9. Again fsck partition using:

   fsck -y /dev/mapper/san01

10. Resize ext file-system to use entire partition using:

    resize2fs /dev/mapper/san01

11. Mount the partition and check increased disk space

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