On 8/25/21 9:26 PM, Samuel Sieb wrote:
You could add a "sync" after the copy and before the "umount".


https://utcc.utoronto.ca/~cks/space/blog/unix/TheLegendOfSync

We're getting into myths and legends territory.  Running sync before umount isn't harmful, but umount will flush any dirty buffers, so it isn't necessary.

I'm not able to reproduce the problem described, though I'm running Fedora 34.  When I attach a USB drive, it is mounted with the "flush" option.  I can copy arbitrarily large file sets to the drive, and the "cp" command appears to be nearly synchronous.  The sequence "time cp ... ; time umount ..." indicates nearly all of the time spent is in the cp command and umount requires between .2 and .3 seconds.

What are the indications that the copy operation originally reported was incomplete?  Does the "umount" command have any flags?  Are there any errors in "dmesg" after the script runs?
_______________________________________________
users mailing list -- users@lists.fedoraproject.org
To unsubscribe send an email to users-le...@lists.fedoraproject.org
Fedora Code of Conduct: 
https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: 
https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org
Do not reply to spam on the list, report it: 
https://pagure.io/fedora-infrastructure

Reply via email to