On 9/9/25 12:33 PM, Cedric Blancher wrote: > On Tue, 9 Sept 2025 at 18:12, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: >> >> On 9/9/25 12:06 PM, Cedric Blancher wrote: >>> Due lack of a VFS interface and the urgend use case of needing to >>> export a case-insensitive filesystem via NFSv4.x, could we please get >>> two /etc/exports options, one setting the case-insensitive boolean >>> (true, false, get-default-from-fs) and one for case-preserving (true, >>> false, get-default-from-fs)? >>> >>> So far LInux nfsd does the WRONG thing here, and exports even >>> case-insensitive filesystems as case-sensitive. The Windows NFSv4.1 >>> server does it correctly. As always, I encourage you to, first, prototype in NFSD the hard-coding of these settings as returned to NFS clients to see if that does what you really need with Linux-native file systems. >> Hi Cedric, >> >> Can you send a pointer to some documentation for the Windows NFSv4.1 >> implementation of this feature? > > That is just ON by default for the Windows NFSv4.1 server if you > export NTFS, and OFF by default for DVDs. > We never had to change it. > > https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/nfsadmin > explains a bit of it, but for Windows Server 2022 and 2025 it's a bit > different. Part of the more interesting docs are behind a > paywall/Microsoft login. The feature is comprised of these three configuration options: translationfile=<file> - Specifies a file containing mapping information for replacing characters in the names of files when moving them from Windows-based to UNIX-based file systems. If file is not specified, then file name character translation is disabled. If the value of translationfile is changed, you must restart the server for the change to take effect. casesensitivelookups={yes|no} - Specifies whether directory lookups are case sensitive (require exact matching of character case). You must also disable Windows kernel case-insensitivity to support case-sensitive file names. To support case-sensitivity, change the DWord value of the registry key, HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\kernel, to 0. ntfscase={lower|upper|preserve} - Specifies whether the case of characters in the names of files in the NTFS file system will be returned in lowercase, uppercase, or in the form stored in the directory. The default setting is preserve. This setting can't be changed if casesensitivelookups is set to yes. Sounds like there is more going on than just setting an export option. I will need to hunt down a Microsoft NFS developer to find out how much the shared file system is involved in handling internal filename resolution. I'm at SDC next week, there should be one or two there. -- Chuck Lever
