UI violates Ubuntu's unit policy

[David D Lowe]

When creating a new logical volume in system-config-lvm, the user can choose between the following units:

"Extents", "Gigabytes", "Megabytes", "Kilobytes".

By "Gigabytes", system-config-lvm actually means gibibytes, and so on for the other units.

This is a violation of Ubuntu's unit policy:

https://wiki.ubuntu.com/UnitsPolicy

What I expected:

- Either 10 based units (such as GB) or 2 based units (such as GiB) to be used.
- The option of using "Bytes", so I can specify the volume size precisely without any ambiguity.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: system-config-lvm 1.1.16-1ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-18.29-generic 3.5.7
Uname: Linux 3.5.0-18-generic i686
ApportVersion: 2.6.1-0ubuntu6
Architecture: i386
Date: Tue Nov 20 17:20:48 2012
MarkForUpload: True
PackageArchitecture: all
SourcePackage: system-config-lvm
UpgradeStatus: Upgraded to quantal on 2012-10-18 (32 days ago)

[Rolf Leggewie (r0lf)]

Thank you for your report. Are you concerned only with the shorthands or are you suggesting that when spelt out Gibibyte be used instead of Gigabyte?

[David D Lowe (flimm)]

It should conform to Ubuntu's policy, which specifies the meanings of both the longhand and the shorthand.

Wherever "gigabyte" or "GB" is displayed, that should mean 1000000000 bytes, wherever "GiB" or "gibibyte" is displayed, that should mean 1073741824 bytes.

[Rolf Leggewie (r0lf)]

Thank you for the reply. I'm all for consistency and correct use of terms. In this case though, while technically correct, I find Gibibytes a bit ridiculous. I'm quite technical but I had to google for the exact meaning. For usability reasons, I'd cast my vote not to use that term. I agree that the correct abbreviations GiB and GB should be used where applicable. In any case, it's not my decision to make.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel U. Thibault (daniel-thibault)]

Rolf Leggewie seems to be in the same camp as Theodore Ts'o, author of the infamous resize2fs man pages. Where Theodore also finds the IEC/IEEE terminology "ridiculous", he at least spells out what units resize2fs does use. Not so with system-config-lvm and its command-line counterparts (lvreduce and others).

Getting the file system and logical volume extents wrong because the units are poorly explained in the man pages or the GUI can cause entire partitions to be lost. That's not "ridiculous", it's tragic.

I'm firmly with David D. Lowe on this issue: stick to IEC/IEEE terminology, and spell it out in the man pages and the GUI, like the Disk Utility (palimpsest) does.