Resolved Error when running Plesk Migrator

[linuxKurt]

Server operating system version

Ubuntu 22.04

Plesk version and microupdate number

Plesk Obsidian 18.0

I am a newbie to Linux and Plesk, not a newbie to server management and web development.

I recently inherited a website running on old VM, and is running Plesk Web Admin Edition 12.5, It has one website on the server which is running fine at the moment, but the OS of the server is CentOS 6.7 and not upgradeable.

I purchased a new Cloud Server, running Plesk Obsidian 18.0. Ubuntu 22.04. I installed the Plesk Migrator Utility and verified all the pre reqs.

When I kick off the migration I am getting the below error and have tried everything I can find online including Plesk Articles on configuring sshd and restarting.

I have tried restarting the migration. Same.
I have tried switching from password to RSA key. Different error, but immediate stop to migration, says it can't find the key named xxxxx, which does exist.

***** error message *****
Failed to fetch basic information about resellers, clients and domains data from source servers
Cause: Command execution failed on the local server with non-zero exit code.
command: rsync -r --chmod=Fu=r,Du=rwx,go= --timeout=30 -e 'ssh -i /usr/local/psa/var/modules/panel-migrator/sessions/20230405142828/ssh-keys/id_rsa.74.208.205.5 -p 22 -o PasswordAuthentication=no -o StrictHostKeyChecking=no -o GSSAPIAuthentication=no' /usr/local/psa/admin/plib/modules/panel-migrator/backend/lib/python/parallels/plesk/source/legacy/extras/plesk_12_5_pmm_shared/ [email protected]:/root/plesk_migrator/plesk_migrator-p66ogd01dqduyzm00itarkxm9xbd0dhu/pmm_agent
exit code: 255
stdout:
stderr: Unable to negotiate with 74.208.205.5 port 22: no matching host key type found. Their offer: ssh-rsa,ssh-dss
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: unexplained error (code 255) at io.c(231) [sender=3.2.7]

That is a critical error, migration was stopped.

 

[Peter Debik]

I have tried switching from password to RSA key.

Good approach.

Different error, but immediate stop to migration, says it can't find the key named xxxxx, which does exist.

Maybe the system is right. Have you considered to create a new key?
Here is more on that topic: Authentication by SSH (Linux)

 

[Maarten]

Could you try the site import extension if it's just one website?

Importing Websites

You may want to import content from a different website that belongs to you but is hosted elsewhere into Plesk. Use t...

docs.plesk.com

 

[linuxKurt]

Good approach.

Maybe the system is right. Have you considered to create a new key?
Here is more on that topic: Authentication by SSH (Linux)

I did try to redo this Peter, I think the problem is negotiating the copy of the key. Below is a screenshot of the error I receive when I try and copy the key using ssh-copy-id [email protected].

It sort of makes sense. How does the target server have permission to copy a file to the source server (public key) without some sort of authorization.

 

[linuxKurt]

Could you try the site import extension if it's just one website?

Importing Websites

You may want to import content from a different website that belongs to you but is hosted elsewhere into Plesk. Use t...

docs.plesk.com

I did look at site import, but it doesn't show my site as an option, need to investigate what it is using to determine which sites I own. Obviously this is a different web server, not sure how it would know to reach out to my other web server and get the site.

 

[Maarten]

If you know that website's FTP user and password, it should work as you can choose the individual folders of the source server.

 

[linuxKurt]

I still have not got this working, today I noticed that in the sshd_config on the source server (centOS) these lines, seems this would block the process,



#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys
#AuthorizedKeysCommand none
#AuthorizedKeysCommandRunAs nobody


it appears because of the age of centOS server, some of the directions in PLESK migration are not relevant as they have SSHD_Config lines that either I don't see or I see extra in my older server.

 

[Peter Debik]

A line that starts with an # is a comment. If you want to active the directives, you need to remove the # from the beginning of the corresponding line.

 

[linuxKurt]

A line that starts with an # is a comment. If you want to active the directives, you need to remove the # from the beginning of the corresponding line.

Yes, that is why I was pointing out, these are commented out and would not allow as written. But I am by no means an expert, so not sure if these are the only lines that are causing issues if they in fact are causing issues.

 

[Kaspar]

#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys
#AuthorizedKeysCommand none
#AuthorizedKeysCommandRunAs nobody

I think you'll need to uncomment those options. At least the first two, but I suspect the others as well. Restart the sshd service after editing.

 

[linuxKurt]

I worked my way thru the RSA issues and got the migration to run, I am running into what I think is a minor issue, but don't know how to resolve. This machine is a brand new VM with 160GB disk that is pretty empty.

stderr: rsync: write failed on "/root/plesk_migrator/plesk_migrator-nndbp288vlgh0lhktnsuh6geal5sh60h/my_localhost_wordpressDB.cnf": No space left on device (28)

stderr: rsync: write failed on "/root/plesk_migrator/plesk_migrator-nndbp288vlgh0lhktnsuh6geal5sh60h/my_localhost_xxx.cnf": No space left on device (28)

 

[Kaspar]

What's the output of the df -h command?

 

[linuxKurt]

What's the output of the df -h command?

 

[Peter Debik]

Enough storage space. Maybe you have many small files that consume all available inodes of the container? Check with df -i /dev/mapper/vg00-1v01.

 

[linuxKurt]

Enough storage space. Maybe you have many small files that consume all available inodes of the container? Check with df -i /dev/mapper/vg00-1v01.

plesk says it is source server, df -h below

 

[linuxKurt]

here are settings , what would be a good temp directory based on above df -h on source server? surely 21g is enough disk space.

 

[linuxKurt]

if i try these settings i get this

stderr: mkdir: cannot create directory `/root/plesk_migrator/plesk_migrator-omb8j8iaetigudav77t1e9wfmrqdwj3l': No space left on device

 

[Maarten]

The source server has no space left. The Plesk migrator wants to:

1. create a backup on the source server
2. transfer the backup to the new server
3. unpack the backup on the new server

So, you have to make room for those temporary backup files on the source server before you start a migration.

Can you move some files from '/' to the '/home' partition?

 

[linuxKurt]

The source server has no space left. The Plesk migrator wants to:

1. create a backup on the source server
2. transfer the backup to the new server
3. unpack the backup on the new server

So, you have to make room for those temporary backup files on the source server before you start a migration.

Can you move some files from '/' to the '/home' partition?

what a good explanation, i can understand this.

i am not well acquainted with linux server, so i dont know how to even do this. on a windows server i could use file explorer. but on ubuntu seems there is different naming. for example when i run df -h i dont see anything called / or even /home. i can see /var has 21g.

i assume i need to

1. check / for files
2. move to /home

i will try to find something that explains 'filesystem' vs 'mounted' on which seems to be important to understand

 

[Maarten]

Linux has a 'find' command that you can use to search for large files.

Search for files larger than 1GB
# find / -size +1G

Or use this command to find the largest directories:
# du -cha --max-depth=1 / | grep -E "M|G"

Or use the ncdu tool to visualize the directories/files:
# apt install ncdu

Once installed type:
# ncdu /