Rsync “failed to set times … operation not permitted”

TrueNAS General
1

Hi,

all my RSYNC Tasks seem to fail as soon as I set the checkmark to preserve the times. An example for an RSYNC Task is:

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I looked at https://forums.truenas.com/t/rsync-fails-with-failed-to-set-times-operation-not-permitted/7308

But did not work for me.

My ACLs for the NetBackup Dataset that I am pulling to on the truenas look like this:

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Parent dataset permissions are basically the same.

What am I missing?

My current version: TrueNAS SCALE Fangtooth 25.04.0

Any help would be greatly appreciated.

2

You look to be using NFSv4-style ACLs (instead of POSIX ACLs) on that dataset.

I believe rsync cannot interpret anything beyond the “owner” for NFSv4 ACLs, which in this case is root. Meanwhile the user running this process is the username master.

You could try setting the owner of the dataset’s root path ACL to master, and possibly not just apply this, but apply it recursively. The “Apply Owner” box needs to be checked when you click Save. Alternatively, you could try to run the task as root instead of master.

Another option is to start all over with POSIX ACLs, instead of NFSv4-style ACLs, which will strip the current ones and replace them with the simpler POSIX ones.

I’m not sure how comfortable you feel with starting all over with your dataset’s ACLs, which will affect all files and folders inside.

3

Hi,

I would be ok starting over with POSIX ACLs, I was not even aware of the specific differences. My current permission structure isn’t overly complicated.

How do I start over however?

I did also just out of curiosity try it by changing the “Owner” to master and the “Group” to builtin_users as well and just like you said with changing the owner the rsync process ran and returned “SUCCESS”. So looks to me that RSYNC can really only read the “Owner”.

Or would it make sense to change User that runs the RSYNC process to root. I think I just had that set to master because that is the user I have on the Synology where I am pulling from however that has been configured and setup so not sure that the user I am using on Truenas for the RSYNC process needs to be the same name.

Thank you for helping!

4

There should be an “Advanced” option in the dataset’s permissions page, which lets you choose the ACL type.

If you do this, make sure to apply the new owner and group and permissions recursively.

EDIT: I’m not saying to do this. If you think it’s worth it, you can. If you’re happy now, you can leave it working.

5

I don’t know why you think changing to posix ACLs will help with this. Changing file timestamps is a place where kernel checks whether the current credential is the file owner or root. Changing ACL type on existing data is something that should only be done as an absolute last recourse as it will potentially break access for everything using the data.

6

That’s why it was last on the list.

If only they want to start over with simpler POSIX ACLs for home use, and they’re using the datatset as an rsync target without regular SMB use.

The owner (or group owner) would still need to be something other than root

7

I see both of your point. In my home use case with not a very complicated permission structure changing owner and/or ACLs isn’t a huge deal and I can do it but I do understand that it could break a lot of things.

Either way this has helped me understand what I was missing and pointed me in the right direction and therefore was helping!

I appreciated it!