File Modification Times Lost on SFTP Upload

[GJS]

I am evaluating NetDrive to map to an Android SSH/SFTP server (https://play.google.com/store/apps/details?id=net.xnano.android.sshserver). When I upload files to the server, the modification time on the copies becomes the time of upload, rather than the modification time of the original file. Changing ‘ Use server time for files/folders’ in the drive’s SFTP options does not help.

Other SFTP clients, such as WebDrive, SFTP Drive, and Beyond Compare, preserve file modification times on uploads to this server (sometimes controlled by an option setting). However, they have other deficiencies for my usage.

Questions:

• Could there be a setting I missed?
• If not, can the problem be fixed for this server? I see similar problem reports for other servers.
• Is there a way I can test a fix if it appears after my evaluation period has expired?

[jyyoon]

Hello.

Thank you for using NetDrive.

I know that sftp does not support “set file time”.

If you need more more evaluation, we can extend it.

Regards.

[GJS]

My guess is that the SFTP clients which set file modification time are using libssh2_sftp_fsync() to flush file metadata. Presumably the SFTP server I am using includes fsync@openssh.com support.

[jyyoon]

Thank you for information.

I will research about that.

Regards.

[jyyoon]

Hello.

I’ve researched about this.

I’m afraid that setting a file timestamp could not be supported with sftp via libssh2_sftp_fsync.

Sorry about that.

Regards.

[GJS]

Thank you for looking into this. Now I wonder what WebDrive, ExpanDrive, and SFTP Drive use to set the file mod time correctly with the same Android SFTP server I am using.