[gpfsug-discuss] [EXTERNAL] Creation time

[Buterbaugh, Kevin Lynn]

Hi all,

One minor correction to the below … while JAB is correct that it is a common misconception that ctime is file creation time, it is also more than “the time you last changed permissions.”  The man page for ls on a RHEL 8 system describes it as “time of last modification of file status information.”  I.e., it’s the time _any_ file metadata was updated … so any update to a files’ inode updates ctime.  Thanks…

Kevin B.
—
Kevin Buterbaugh
Sandia National Laboratories - HPC Development (9328)
Office: (505)284-1470, Work iPhone: (505)288-1959
my_email = "@".join(["klbuter", ".".join(["sandia", "gov"])])

On Oct 1, 2026, at 7:34 AM, Jonathan Buzzard via gpfsug-discuss <gpfsug-discuss at gpfsug.org> wrote:

On 01/10/2026 14:22, Ahmed Essam Mahrous Gaber Elmazaty via gpfsug-
discuss wrote:
In addition to rsync, we have migrated to GPFS using AFM and it
preserves all the metadata including modification timestamps Best
regards,
If it does then a GPFS API must exist even if undocumented for modifying it. However I don't think it does.

Note that creation/birth time is not POSIX and GPFS only acquired it in version 3.2 from memory, at the same time as MS-DOS attributes were added. Presumably added as part of being able to mount GPFS on Windows, with the fun fact you needed a GPFS file system created under 3.2 or later to do so.

It is a common misconception that ctime is a creation time, it is in fact the time you last changed permissions.

I am talking about the "Creation Time" as reported by mmlsattr -L or on XFS the Birth time you see on when stating the file.


JAB.

--
Jonathan A. Buzzard                         Tel: +44141-5483420
HPC System Administrator, ARCHIE-WeSt.
University of Strathclyde, John Anderson Building, Glasgow. G4 0NG

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