Bryce brought up a good point that silently truncating 9.5G to 9G could be misleading for users. I made an upstream bug report to see if that behavior could potentially be improved upon[0].
For now, I'll wait to hear from upstream rather than pushing these fixes into Jammy and Focal. [0] - https://sourceforge.net/p/gptfdisk/discussion/939590/thread/d6c0241a23/ ** Description changed: [ Impact ] When creating a partition with sgdisk, if you provide a decimal input it will be incorrectly interpreted. For example, putting in the command sgdisk --new=1:0:+7.5G --typecode=1:8300 ./a.img to create a 7.5G partition, the tool will actually create a 3.5K partition. [ Test Plan ] $ lxc launch ubuntu:jammy j $ lxc shell j # apt update -y && apt upgrade -y # apt install -y gdisk # fallocate -l 10G a.img # sgdisk --new=1:0:+7.5G --typecode=1:8300 ./a.img # fdisk -l ./a.img | grep filesystem | awk '{print $5}' 3.5K (Test Fix Jammy) # add-apt-repository ppa:mitchdz/lp2039594-gdisk-decimal # apt install -y gdisk # dpkg -s gdisk | grep Version: Version: 1.0.8-4ubuntu1~jammy1 # rm ./a.img # fallocate -l 10G a.img # sgdisk --new=1:0:+7.5G --typecode=1:8300 ./a.img # fdisk -l ./a.img | grep filesystem | awk '{print $5}' 7G ( Test Fix focal) # add-apt-repository ppa:mitchdz/lp2039594-gdisk-decimal # apt install -y gdisk # dpkg -s gdisk | grep Version: Version: 1.0.5-1ubuntu1~focal3 # rm ./a.img # fallocate -l 10G a.img # sgdisk --new=1:0:+7.5G --typecode=1:8300 ./a.img # fdisk -l ./a.img | grep filesystem | awk '{print $5}' 7G [ Where problems could occur ] * Some tool could be used to this behavior and fixing this could cause what is assumed to be a regression. * Adds a new while loop, while potentially negligible, will use more CPU cycles. + * Silently truncating, for example, 9.5G to 9G could be misleading for users. [Original Bug Descriptio] When using the sgdisk command to create a new partition with a specified size, the tool behaves unexpectedly when a size is specified with a decimal point. Specifically, using a size like 7.5G results in the partition size being set to 3.5 KiB instead. Steps to Reproduce: Run the following command to create a partition: sgdisk --new=1:0:+7.5G --typecode=1:8300 --change-name=1:boot /dev/sda Verify the size of the newly created partition using sgdisk --print /dev/sda. Expected Behavior: The partition size should be set to 7.5 gigabytes, as specified in the --new command. Actual Behavior: The partition size is set to 3.5 KiB. Additional Information: The issue can be worked around by specifying the size in megabytes, such as 7500M. System Information: Operating System: Ubuntu 22.04.3 LTS sgdisk Version: GPT fdisk (sgdisk) version 1.0.8 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2039594 Title: sgdisk - Unexpected Behavior with Decimal Point in Partition Size Specification To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdisk/+bug/2039594/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
