[SOLVED] Creating the Datastore is not Working - EPERM Operation not permitted

[YaseenKamala]

I gave my NFS share and folder on the TrueNAS chmod 777 so no protection at all and everyone got full read/write/execute access. Because I'm not using kerberos there isn't any authentification anyway, so everyone could pretend to be root without needing to have the root password.

If I remember right I also needed to add the NFS share in PBS as NFSv3 because there was a problem with v4 locking files.

I have done that as well but it's not working to!

This is strange, I have tried to change the UID and GID for a test user on Synology NAS but all the are commands are not working I don't know @angelkille did that?

I gave my NFS share and folder on the TrueNAS chmod 777 so no protection at all and everyone got full read/write/execute access. Because I'm not using kerberos there isn't any authentification anyway, so everyone could pretend to be root without needing to have the root password.

If I remember right I also needed to add the NFS share in PBS as NFSv3 because there was a problem with v4 locking files.

 

[YaseenKamala]

Hello @Dunuin ,

For information I managed to create the datastore by creating "a user and a group" on both PBS and Synology NAS with the exact UID and GID I am attaching the screenshots in case someone needs it )





Creation of normal Group and User on Synology NAS create with Web Interface:






First I checked the Identifications on Synology NAS for PBS group and user




At this point logged into my PBS CLI and create the GROUP and User with the exact details. see bellow



Commands that I used:
groupadd -g 65537 PBS


One the group has been created with the correct "GID" then created the user ↓
useradd -u 1035 -g 100 -p $userpassword



At the end I restarted both Synology NAS and PBS and was able to create the datastore from the mounted point

Again and again thank you so much for your great support dear @Dunuin

 

[Cecil]

I added the users but still no dice, I followed this guide and was able to add the datastore. ( https://geekistheway.com/2021/03/07...or-proxmox-backup-server-to-use-as-datastore/)

It still doesn't work right but At least I was able to add a datastore instead of the eperm denied


I think the change is that using this guide, the squash map option was set to "no mapping" and that made the difference for me.
Still trying to figure out how to fix the permission but maybe this helps someone else on this forbidden path.

Final edit, I used: chmod -R 777 /mnt/whateveryourmountpointis
and immediately the permission errror dissapeared.
From what I understand 777 is windows' "everyone" permission and not recommended but I'm also a total linux noob and don't know any better.

 

[soporteit]

Hi,
I am working with the same idea, mounting NFS directory in proxmox-backup server, but from QNAP NAS server.
I have the same problems



In my case, i test the configuration with differents squash options, differents group id options, differents user id options, but nothing resolve the problem.
I reveived allways the same error message



When I mount with nfs the folder from QNAP server without problems, I can create files and directories



But when tried to add datastore, is impossible.
I suppouse proxmox-backup work with user backup, and it can not change the permissions on the nfs directory, and can not create .chunk directory,

I can't find debug information about proxmox-backup logs, search in /var/logs/proxmox-backup and in /var/logs but there arent usefull

 

[hectorinfobit]

I'm using a Netgear NAS and had the same problem, I solved it by disabling the UID/GID combination, in this case, choose the option "not combining root"

 

[lampe80]

For Synology NAS i found a solution,

On Synology the NFS rule 'Squash" have to be set to "No mapping"

 

[ogghi]

Thanks, no squash was missing here on my end as well right now

 

[PPee]

For Synology NAS i found a solution,

On Synology the NFS rule 'Squash" have to be set to "No mapping"

View attachment 57717

I have set "map all users to admin", because admin has all permissions to read and write the data, so I presume that if the PBS user accesses the share, it is mapped to admin and therefore inherits all the rights.

 

[PPee]

I have set "map all users to admin", because admin has all permissions to read and write the data, so I presume that if the PBS user accesses the share, it is mapped to admin and therefore inherits all the rights.

Ok I followed the advice of lampe
When I change this to "no mapping" I can add the datastore, and when adding, I can see that chunks are created and the task reports OK, but when I go to the summary of the added datastore it says "datastore is not available" and in the tab "content" it says "bad request (400) unable to open chunk store ..... permission denied (OS Error 13). So it looks like the PBS is able to create the initial chunks, but it does not have the permission to read them.
In the vm I can see the chunks, all with backup:backup as username-password.
I also tried to create the backup user on the Synology, but that is a reserved username, you cannot add...

 

[PPee]

mmm I think I solved it. I created a user with the same UID (34 in my case) on the synology NAS and gave it permission for reading and writing in the shared folder with the ssh command: sudo synouser --add BackupUser <pw> "Backup User" 0 "" "User"