[XenServer Update failed with error "Syncing with remote YUM repository failed"]

Was this a host that was getting updates earlier and failed recently ?

Can you attach /var/log/xensource.log from your host here ? ( Assuming there is no proxy )

 

[XenServer 8 LTSR Updates]

Hello Eric,

Supplemental packs (including driver disks) are used to modify and extend the functionality of the XenServer host, by installing software into the control domain (dom0) , this is different from host updates. Currently, Internet access is a necessity for XenServer 8 updates. Rfer : https://docs.xenserver.com/en-us/xenserver/8/update/apply-updates-using-xc 

 

To provide update notifications, XenCenter requires internet access. If your XenCenter is behind a firewall, ensure that it has access to the updates.ops.xenserver.com domain. 

To receive the updates, your XenServer hosts require internet access. If your hosts are behind a firewall, ensure that they have access to subdomains of ops.xenserver.com.

However you should be able to use a proxy server and apply the updates. Refer : https://docs.xenserver.com/en-us/xenserver/8/update/apply-updates-using-xc#configure-updates-for-your-pool
 

(Optional) Under Proxy Server, specify a proxy to use when synchronizing with the update channel. This proxy server is used for communication between the host and the public CDN.

 

[Delete Virtual Xe Recovery File System]

Can you ensure that none of your VMs are actively using it ?

Can you try to run the following on all the hosts in the pool and see if you are getting an output ? 

tap-ctl list | grep -i 8e18c874

[Cannot Connect to XenServer from XenCenter]

 @Steven Schoch Do you believe you can log this as a ticket at https://bugs.xenserver.com/ ?