On 2024-04-27 07:08, Roland Mainz via Cygwin wrote:
Are the |FILE_ID_BOTH_DIR_INFORMATION| fields
|ShortName|+|ShortNameLength| mandatory these days, e.g. is it legal
to set |ShortNameLength = 0;| for Cygwin 3.4/3.5 in Windows 10 ?
MS Windows 8/Server 2012+ disabled 8.3 short name generation on new
volumes/partitions, for example see:
https://ss64.com/nt/syntax-filenames.html
https://archive.techarp.com/showarticle53b4.html?artno=827
https://learn.microsoft.com/en-ca/archive/blogs/josebda/windows-server-2012-file-server-tip-disable-8-3-naming-and-strip-those-short-names-too
https://learn.microsoft.com/en-ca/windows-server/administration/windows-commands/fsutil-8dot3name
This really makes a big difference on directories like /var/log/ and /tmp/ if
apps create a lot of files with similar name prefixes there, for example,
date/time suffixed long file names from multiple hourly cron jobs, as long names
can be queried via the B-tree but short names have to be scanned sequentially.
Is there anything else for a filesystem driver to do to indicate that
|ShortName| support is not available ?
Also see fsutil behavior query|set disable8dot3 [[<volumepath> [{1|0}]]|<value>]
% fsutil 8dot3name set /?
usage : fsutil 8dot3name set [0 through 3] | [<Volume Path> 1 | 0]
When a volume is not specified the operation updates the registry value:
0 - Enable 8dot3 name creation on all volumes on the system
1 - Disable 8dot3 name creation on all volumes on the system
2 - Set 8dot3 name creation on a per volume basis
3 - Disable 8dot3 name creation on all volumes except the
system volume
When a volume is specified the operation updates the individual
volume's on disk flag. This operation is only meaningful
if the registry value is set to 2.
0 - Enable 8dot3 name creation on this volume
1 - Disable 8dot3 name creation on this volume
This operation takes effect immediately (no reboot required).
Sample commands:
"fsutil 8dot3name set 1" - disable 8dot3 name creation on all volumes
"fsutil 8dot3name set C: 1" - disable 8dot3 name creation on c:
% regtool get -v
/proc/registry/HKEY_LOCAL_MACHINE/System/CurrentControlSet/Control/FileSystem/NtfsDisable8dot3NameCreation
2
% fsutil 8dot3name query c:
The volume state is: 0 (8dot3 name creation is enabled).
The registry state is: 2 (Per volume setting - the default).
Based on the above settings, 8dot3 name creation is enabled on c:
% fsutil 8dot3name query d:
The volume state is: 0 (8dot3 name creation is enabled).
The registry state is: 2 (Per volume setting - the default).
Based on the above settings, 8dot3 name creation is enabled on d:
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Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
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