How to access backup on a NAS

[hmiersch]

Ubuntu Version:
originally 24.04, now 25.04

Desktop Environment (if applicable):
the desktop that comes wit ubuntu. not sure what it’s called.

Problem Description:
i made backups of my internal HD to my NAS (a synology DS 423+, in case that matters) and then my internal HD failed. now i want to access that backup but deja dup gives me nothing but error messages. when i try to access the backup via NFS, it says “mount point does not exist” and if i try SMB, it complains that it needs a host name and a share name. but where do i put those? what’s the syntax? also, my NAS has an IP address, not a name.

Relevant System Information:
ubuntu 25:04 running on an intel i7 with 32GB ram
synology ds423+ with 4 2TB HDs running DSM 7.2.2

Screenshots or Error Messages:

What I’ve Tried:
i’ve tried variations on the network address;

• NFS and SMB protocols
• with or without a colon after the IP address
• with or without “volume1” at the beginning of the path
• with or without “harry” at the end

[Actionparsnip]

If you manually mount the NFS can you access it OK?

[hmiersch]

i have this line in my fstab file:
192.168.1.8:/volume1/ /mnt/ds423 nfs x-systemd.automount 0 0
that should mount it on startup, right?

[Actionparsnip]

Should be OK. I’d remove the trailing slash on the remote side, or try:
192.168.1.8:/volume1 /mnt/ds423 nfs auto,rw,bg,hard,intr 0 0
Save the file then run:

systemctl daemon-reload && sudo mount /mnt/ds423

Should do it

[hmiersch]

i added that line to my fstab file, and then i said:
systemctl daemon-reload && sudo mount /mnt/ds423
and it gave me this output:
mount: /mnt/ds423: mount point does not exist. dmesg(1) may have more information after failed mount system call.
should i use /dev/ instead of /mnt/?

edit: i tried it, and the result was the same: mount point does not exist.

i just checked: my /mnt directory is empty, and there’s nothing called ds423 in /dev either. what am i doing wrong?

[ricmarques]

Hi, @hmiersch

I suggest that you first create the directory for the mount point:

sudo mkdir -pv /mnt/ds423

… and then try again to do the mount:

sudo mount -v /mnt/ds423

I hope this helps

[hmiersch]

i created that directory but that didn’t help.

and when i say
sudo mount -v /mnt/ds423
i get the following error message:
mount: /mnt/ds423: bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program. dmesg(1) may have more information after failed mount system call.

BTW, how can anyone call deja dup “easy to use” and “user friendly”??? it’s given me nothing but error messages, mostly “mount point does not exist”
so far it has proven impossible to restore those backups

[ricmarques]

Hi again, @hmiersch

Please, try the following command in your Ubuntu machine to see what NFS exports are available from your Synology NAS :

showmount -e 192.168.1.8

When you do that, it’s possible that you get the following error message:

Command 'showmount' not found, but can be installed with:
sudo apt install nfs-common

If that’s the case, please follow that advice and enter the following command to install the “nfs-common” package:

sudo apt install nfs-common

… and then try again the first command to see what are the available NFS exports from your NAS:

showmount -e 192.168.1.8

[hmiersch]

i had to install nfs-common, and when i said
showmount -e 192.168.1.8
it gave me the following output:
Export list for 192.168.1.8: /volume1/data 192.168.1.1/24 /volume1/Media files 192.168.1.64 /volume1/Backups 192.168.1.64
so far so good. but deja dup still complains that the
mount point does not exist

[ricmarques]

Hi again, @hmiersch

Great! We’re definitely making good progress then Now that you have the nfs-common package installed, I believe you will be able to access your backups by doing the following:

1 - Create a mountpoint for the Backups:

sudo mkdir -pv /mnt/ds423/Backups

2 - Do the NFS mount for the exported Backups directory (probably, the previous attempts to do the “mount” were failing because the nfs-common package hadn’t been installed yet):

sudo mount -v -t nfs 192.168.1.8:/volume1/Backups /mnt/ds423/Backups 

3 - List the content of the Backups directory to confirm that you now see your Backups:

ls -l /mnt/ds423/Backups 

I hope this helps. Please, keep us posted!

[hmiersch]

hello.
for some reason there are already 3 directories, Backups, data and Media files, in my /mnt/ds423 directory. weird.
trying to remove them resulted in “permission denied” errors.

sudo mount -v -t nfs 192.168.1.8:/volume1/Backups /mnt/ds423/Backups
gives me the following output:
mount.nfs: timeout set for Sun Jun 29 15:29:35 2025 mount.nfs: trying text-based options vers=4.2,addr=192.168.1.8,clientaddr=192.168.1.64 mount.nfs: mount(2): Protocol not supported mount.nfs: trying text-based options vers=4,minorversion=1,addr=192.168.1.8,clientaddr=192.168.1.64

edit: fixed some typos.

[ricmarques]

Hello again, @hmiersch

Hmmm… I’m wondering if the “automounter” option in your fstab (x-systemd.automount) is now getting activated, because the nfs-common package is now installed. What happens if you do the following? Do you see your Backups files / directories?

cd /mnt/ds423/Backups
ls -l 

IF you don’t see your backed up files / directories in that “Backups” directory, could you then please check if you already have any NFS mounts active, by doing the following command:

grep nfs /proc/mounts

IF you also don’t see any mounts active by that last grep command, may I ask what happens when you try to do the following variation of the mount command, to force the use of NFSv4:

sudo mount -v -t nfs4 192.168.1.8:/volume1/Backups /mnt/ds423/Backups

Speaking of NFSv4, could you please check what is the “Maximum NFS Protocol” that you have configured in your “Synology DS 423+” NAS ? I’ve found the following related article in the Synology support / Knowledge Base (“Synology Knowledge Center”) web site, for DSM 7.2 (DiskStation Manager 7.2):

https://kb.synology.com/en-au/DSM/help/DSM/AdminCenter/file_winmacnfs_nfs?version=7

[hmiersch]

hello.
your comment about automount got me thinking, and i commented out that line in fstab, then restarted the computer. remember the 3 directories i mentioned in my last post? earlier it looked like they were gone but now they’re back.

ls /mnt/ds423/Backups
gives me a permission denied error.

grep nfs /proc/mounts
gives me the following output:
192.168.1.8:/volume1 /mnt/ds423 nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0 192.168.1.8:/volume1/Backups /mnt/ds423/Backups nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0

sudo mount -v -t nfs4 192.168.1.8:/volume1/Backups /mnt/ds423/Backups
gives me
mount.nfs4: timeout set for Mon Jun 30 12:56:25 2025 mount.nfs4: trying text-based options 'vers=4.2,addr=192.168.1.8,clientaddr=192.168.1.64' mount.nfs4: mount(2): Protocol not supported mount.nfs4: trying text-based options 'vers=4,minorversion=1,addr=192.168.1.8,clientaddr=192.168.1.64' mount.nfs4: mount(2): Device or resource busy

[ricmarques]

Hi again, @hmiersch

You wrote:

@hmiersch

(…)
ls /mnt/ds423/Backups
gives me a permission denied error.

grep nfs /proc/mounts
gives me the following output:

192.168.1.8:/volume1 /mnt/ds423 nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0
192.168.1.8:/volume1/Backups /mnt/ds423/Backups nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0

(...)

OK. That’s great So, it seems that the /mnt/ds423/Backups directory is already correctly mounted via NFS, but probably it’s owned by “root” or by a different user than what’s your current user. Please try do the following, to give ownership, to your current user, to those 2 directories:

sudo chown -v $USER /mnt/ds423

sudo chown -v $USER /mnt/ds423/Backups

And then try again to do the listing of the “Backups” directory:

cd /mnt/ds423/Backups
ls -l 

[hmiersch]

hello.
i tried those commands. the first one worked no problem. but the second one gave me a “no such file or directory” error. those 3 directories are gone again
is that because that line in my fstab is commented out?

should i reactivate that line in fstab again? currently it is
192.168.1.8:/volume1 /mnt/ds423 nfs auto,rw,bg,hard,intr 0 0
should i change something in that line?

BTW, trying to mount manually results in
mount.nfs4: mount point /mnt/ds423/Backups does not exist

[ricmarques]

Hello again, @hmiersch

Hmm… This time, it may be that the automounter is waiting for you to enter the directory first to mount it. This may seem to be a bit of a “catch-22” problem, but try to do the following:

cd /mnt/ds423/Backups
sudo chown -v $USER /mnt/ds423
sudo chown -v $USER /mnt/ds423/Backups
ls -l

If that ls -l shows your backup-ed files / directories, you’re probably now “good to go”

[hmiersch]

that results in an error message because as i said in my last post, the 3 directories are gone. IOW, /mnt/ds423 is empty.

[ricmarques]

OK, @hmiersch Then, I suggest that you try something else:

1 - Unmount the NFS directory in case it is mounted:

cd /
sudo umount -v /mnt/ds423

2 - Create the mountpoint directory /mnt/ds423/Backups

sudo mkdir -pv /mnt/ds423/Backups

3 - Comment out the following line in the fstab:

192.168.1.8:/volume1 /mnt/ds423 nfs auto,rw,bg,hard,intr 0 0

4 - Add the following 2 lines in the fstab (basically, I’m using the same options that you found previously when you did the grep nfs /etc/mounts/ )

192.168.1.8:/volume1 /mnt/ds423 nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0
192.168.1.8:/volume1/Backups /mnt/ds423/Backups nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0

5 - Try to mount manually each of the two directories at a time:

sudo mount -v /mnt/ds423
sudo mount -v /mnt/ds423/Backups

6 - Change the ownership of the mounted directories:

sudo chown -v $USER /mnt/ds423
sudo chown -v $USER /mnt/ds423/Backups

7 - Try to list the content of the /mnt/ds423/Backups

ls -l /mnt/ds423/Backups

I hope that works, because I must admit that I’m starting to run out of ideas

[hmiersch]

@ricmarques

cd /
sudo umount -v /mnt/ds423

sudo mkdir -pv /mnt/ds423/Backups

**3** - Comment out the following line in the fstab:

192.168.1.8:/volume1 /mnt/ds423 nfs auto,rw,bg,hard,intr 0 0

**4** - Add the following 2 lines in the fstab (basically, I’m using the same options that you found previously when you did the `grep nfs /etc/mounts/` )

192.168.1.8:/volume1 /mnt/ds423 nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0
192.168.1.8:/volume1/Backups /mnt/ds423/Backups nfs4 rw,relatime,vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8 0 0

so far so good

sudo mount -v /mnt/ds423

and this is where the problems start. i get the following output:
mount.nfs4: timeout set for Wed Jul 2 18:32:02 2025 mount.nfs4: Ignore unsupported nfs4 mount option 'namlen' in 'vers=4.1,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8' mount.nfs4: trying text-based options 'vers=4.1,rsize=131072,wsize=131072,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.1.64,local_lock=none,addr=192.168.1.8' mount.nfs4: mount(2): Device or resource busy

also, yesterday my /mnt/ds423 was empty, so i manually created /mnt/ds423/Backups, but when i tried to
ls /mnt/ds423/Bachups
i got a permission denied error. i created that directory myself, and i can’t access my own directory??? what the BEEP is going on???
and now all 3 directories are back, probably thanks to those 2 lines i added to fstab.

and here’s another question: if we ever get this to work, what should i see? an icon on the desktop? an entry in the finder window? an icon in the dock?

[ricmarques]

Hi again, @hmiersch

You wrote:

@hmiersch

(…) and now all 3 directories are back, probably thanks to those 2 lines i added to fstab.

OK. Given that you say that “and now all 3 directories are back”, may I ask what happens when you try to do the following:

@ricmarques

6 - Change the ownership of the mounted directories:

sudo chown -v $USER /mnt/ds423
sudo chown -v $USER /mnt/ds423/Backups

Now, for your other question:

@hmiersch

and here’s another question: if we ever get this to work, what should i see? an icon on the desktop? an entry in the finder window? an icon in the dock?

… I confess that I don’t know how “Déjà Dup” backups and/or Synology work Maybe someone else here in this Community may help you there?