'partx -v -a /dev/sdx' shows incorrect device size and fails to update kernel about the partition table changes for >2.0TB disks using GPT
Issue
-
After adding a new partition to the
7.5 TB
disk havingGPT
label, whenpartx -a -v /dev/sdx
command was run to update the kernel about partition table changes, it showed incorrect disk size, sector values, partition size and was failed to update the kernel about partition table changes. -
This issue was observed while trying to add 3rd partition to the following
7.5 TB
disk which had first2
partitions already mounted and in-use on system:[root@localhost ~]# parted /dev/vdb GNU Parted 2.1 Using /dev/vdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: Virtio Block Device (virtblk) Disk /dev/vdb: 7516GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 1074MB 1073MB ext3 2 1074MB 3110GB 3108GB
o Created a new partition on
/dev/vdb
while/dev/vdb1
was mounted:[root@localhost ~]# parted /dev/vdb "mkpart \" \" 3109555 6040870" Warning: WARNING: the kernel failed to re-read the partition table on /dev/vdb (Device or resource busy). As a result, it may not reflect all of your changes until after reboot. [root@localhost ~]# parted /dev/vdb set 3 lvm on Warning: WARNING: the kernel failed to re-read the partition table on /dev/vdb (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
o New partition was created by
parted
command:[root@localhost ~]# parted /dev/vdb GNU Parted 2.1 Using /dev/vdb Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) p Model: Virtio Block Device (virtblk) Disk /dev/vdb: 7516GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 1074MB 1073MB ext3 2 1074MB 3110GB 3108GB 3 3110GB 6041GB 2931GB lvm
o But while running
partx
command to update the kernel about partition table changes, it showed following errors:[root@localhost ~]# partx -v -a /dev/vdb device /dev/vdb: start 0 size 1795162112 <---------- incorrect disk size gpt: 3 slices # 1: 2048- 2097151 ( 2095104 sectors, 1072 MB) # 2: 2097152-1778382847 (1776285696 sectors, 909458 MB) <---------- incorrect size of 2nd and # 3: 1778382848--1086326785 (1430257664 sectors, 732291 MB) 3rd partitions BLKPG: Device or resource busy error adding partition 1 BLKPG: Device or resource busy error adding partition 2 BLKPG: Device or resource busy <---------- failed to update kernel about partition table changes error adding partition 3 dos: 0 slices
Environment
- Red Hat Enterprise Linux 6
- A disk device with size more than
2.0 TB
andGPT
label
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