Delta backup fails on SMB remote

johnarvid

I will try to import it and check.
But does it matter? Normal backup works, delta backup does not.

johnarvid

But yes, the VDI that was mentioned in the error is working as expected.
Let me know if there is anything else I should try.

olivierlambert

From XO, what's the result of:

ls -lah '/run/xo-server/mounts/93d6810c-711c-4c13-b5ba-9009f3d75933/xo-vm-backups/f8d7e336-57ac-5d98-7825-98c722ef927c/vdis/7e734662-59e8-45cd-a5e0-3abedeecf0dc/621d81e1-0ea2-4155-a7d4-0966b607fb60/20210409T130439Z.vhd`

johnarvid

@olivierlambert Do you mean from xcp-ng?
ls: cannot access .... No such file or directory
There is no xo-server folder in /run/

olivierlambert

Does it ring any bell @julien-f ?

julien-f

Maybe your remote is not mounted, you can try to disable/enable the remote.

johnarvid

@julien-f Do you mean that the remote is not mounted when a normal backup completes successfully but a Delta backup fails?
How can I go forward?

julien-f

@johnarvid I was answering the ls problem, not the initial message of the thread

Backup issues should be self correcting, does the next run not fix the situation for you?

If not, you can take a look at the integrity of your backup files: https://xcp-ng.org/forum/topic/2994/check-backup-integrity/5

johnarvid

@julien-f Ok, understand:)
I missunderstood @olivierlambert "From XO" description. I ran that command from the xcp-ng server, and not from the XO server.

I ran it now and the ls command is successfull.

A next run does not fix the situasion.

vhd-cli check returns OK.
Do you want me to run the xo-backups clean-vms also?

DeOccultist

@johnarvid That error looks like the error that I've been getting... https://xcp-ng.org/forum/topic/4353/delta-backup-failed-invalid-argument

I've switched back to full backups for now.
I'm still investigating and troubleshooting though so no solutions yet...

johnarvid

@deoccultist Thanks for the reply.
I have tried all the steps that @julien-f suggested to you in the last post in your topic.
Guess I have to wait until they have something new I should try.

johnarvid

I have tested with a clean install of xcp-ng with the latest patches. (Just to make sure it was nothing there causing a problem)
But the issue is still there.

johnarvid

I can add information that using a share on windows 10 as remote causes this error.
But using samba on linux with this config is ok:

[global]
  workgroup = BERG
  server string = ember
  security = user
  guest ok = no
  map to guest = Bad Password
  log file = /var/log/samba/%m.log
  max log size = 50
  printcap name = /dev/null
  load printers = no
  min protocol = SMB2
  ntlm auth = yes

[localNetwork]
  comment = Local Network Storage
  path = /mnt/storage/localNetwork
  browsable = yes
  read only = no
  guest ok = no
  valid users = local,john-arvid
  force group = samba
  force user = local

olivierlambert

So could it be permission related on Windows share?

DeOccultist

@olivierlambert I don't think it's a permission error since the same Windows Server 2019 SMB share works fine with full back ups.

olivierlambert

That's because delta is using temporary files named with a dot first. Maybe something causing a problem on your share?

vbits

@olivierlambert Hi, sorry for writing here but I didn't want to open a topic just out of curiosity/doubt.
I have been reading the backup documentation in XOA and it says that they don't advise backups with SMB if the VMs are bigger than 50GB. Why?
I have configured 2 different backups and I noticed that with SMB is much faster than with NFS... how is it possible? but in the end as you say that it is not recommended I have left the NFS.

Darkbeldin

@vbits Hi,
Mostly because NFS offer better speed than SMB with small and medium files, but depending on the storage type SMB can be necessary, for your test result difficult to say it's a full backup personally I have this kind of speed with NFS:

What's the appliance behind your remote?

vbits

@Darkbeldin I did a lot of tests months ago, changed the NFS from 3 to 4.1 as well and never managed to match the speed of SMB.

"What's the appliance behind your remote?"
I'm sorry, but I don't understand the question...
you mean what kind of external Storage for backups? truenas on a NexentaStor SC216.

Darkbeldin

@vbits said in Delta backup fails on SMB remote:

NexentaStor SC216

Yes that was the question If you have better speed with SMB stay with it NFS should be better in theory but sometime you have to go with real world reality.