What is growpart utility and how to use it ?

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Issue

  • How to extend a partition using the growpart utility online?

Resolution

Disclaimer: The following information has been provided by Red Hat, but is outside the scope of the posted Service Level Agreements and support procedures (Production Support - Red Hat Customer Portal). The information is provided as-is and any configuration settings or installed applications made from the information in this article could make the Operating System unsupported by Red Hat Global Support Services. The intent of this article is to provide information to accomplish the system's needs. Use of the information in this article at the user's own risk.

From a technical point of view, resizing filesystems and their underlying partitions (making changes to the existing partition table) can be very dangerous. Also, it is only possible to resize partitions from their end position on the disk. It is not possible to move partitions on the disk or resize them from their beginning. Such operations can result in a corrupted partition table, which will render all data on the disk device inaccessible, leading to data loss. While it is possible to perform online partition resize operation, it is not recommended simply from a data integrity standpoint and not because it's not possible.

  • What is growpart utility?
  1. growpart is one of the utility to extend the last partition of the disk to fill the available free space on the disk. It changes the sector position to the end sector of the disk.
  2. It only extends the last partition. It doesn't create or delete any existing partition.
  3. It can be run online. Dry run test can also be done to check the same.
  • Extend the partition:
root@rhelbox ~]# growpart -v /dev/sde 1
CHANGED: partition=1 start=2048 old: size=1675264 end=1677312 new: size=4192223 end=4194271

Here growpart's first argument is disk and second argument is partition number.

  • Verify the partition table:
[root@rhel7 test6]# parted /dev/sde u s p
Model: VMware Virtual disk (scsi)
Disk /dev/sde: 4194304s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start  End       Size      Type     File system  Flags
 1      2048s  4194270s  4192223s  primary
  • Once the partition has been extended, Resize the physical volume which is using it (Only if PV exists on top of it).
  • From cloud-utils-growpart-0.33* on-wards, Underlying physical volume automatically gets resized once the partition is increased.

Diagnostic Steps

  • Verify growpart package is installed, If not then install:
[root@rhel7 ~]# rpm -qa| grep -i growpart

[root@rhel7 ~]# yum install cloud-utils-growpart -y

OR

# rpm -ivh cloud-utils-growpart/path/to/rpm
  • Verify the partition table using the below command before running growpart:
[root@rhel7 test6]# parted /dev/sde u s p
Model: VMware Virtual disk (scsi)
Disk /dev/sde: 4194304s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 

Number  Start  End      Size     Type     File system  Flags
 1      2048s  839679s  837632s  primary

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