This article will help how you can upload a PC upgrade binary to the PCVM manually using SCP.

Step 1: Understanding the Issue 

When attempting to upload a binary file to the Nutanix PC VM using the scp command, you might encounter the following error:

subsystem request failed on channel 0

For example:

>10:30:22]--0]--user] ~/Desktop scp generated-pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-metadata.json nutanix@x.x.x.226:/home/nutanix/tmp
Nutanix Controller VM
nutanix@x.x.x.226's password: 
subsystem request failed on channel 0
scp: Connection closed

This error indicates that the remote server does not support the SCP protocol.

Step 2: Enable SCP Protocol on the PC VM

1. Edit the SSH Configuration File
   Open the /etc/ssh/sshd_config file on the PC VM and uncomment the following line:

   Subsystem sftp /usr/libexec/openssh/sftp-server
   

2. Restart the SSH Service
   After making the change, restart the SSH service:

   sudo systemctl restart sshd
   

Step 3: Upload the Binary File

Once the SCP protocol is enabled, you can upload the binary file. Use the following command as an example:

>10:33:00]--0]--user] ~/Desktop scp generated-pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-metadata.json nutanix@x.x.x.226:/home/nutanix/tmp
Nutanix Controller VM
nutanix@x.x.x.226's password: 
generated-pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-metadata.json  100% 7313   28.9KB/s   00:00

Similarly, upload the main binary file:

>10:46:25]--0]--user] ~/Desktop scp pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-x86_64.tar.gz nutanix@x.x.x.226:/home/nutanix/tmp
Nutanix Controller VM
nutanix@x.x.x.226's password: 
pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-x86_64.tar.gz  100% 10GB 1.9MB/s 1:30:05

Step 4: Add the Binary to Prism Central

To make the uploaded binary available for upgrades, run the following command on the PC VM:

ncli software upload software-type=PRISM_CENTRAL file-path=/home/nutanix/tmp/pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-x86_64.tar.gz meta-file-path=/home/nutanix/tmp/generated-pc.2024.2-9749c3e486627991f926f48f97b00b2414fc4d70-metadata.json

You should see a confirmation like this:

Uploading a software might take a while.

Type                      : Prism Central  
Name                      : pc.2024.2  
Version                   : pc.2024.2  
Total size                : 9.79 GiB (10,516,091,892 bytes)  
Status                    : completed

Step 5: Complete the Upgrade via the GUI

1. Log in to the Prism Central GUI.
2. Click the gear icon in the top-right corner.
3. Navigate to Prism Central Upgrade.
4. The uploaded binary should now be visible.
5. Select the binary and proceed with the upgrade.

Step 6: Revert the SCP Configuration (Optional)

If you enabled the SCP protocol temporarily in Step 2, you can comment out the line in the SSH configuration file:

# Subsystem sftp /usr/libexec/openssh/sftp-server

Restart the SSH service again:

sudo systemctl restart sshd