Minor Description
When using the script from https://pylonpower.wordpress.com/2012/09/12/nagios-check-script-for-xenserver-6-x/ to check CPU and memory usage of both the XenServer hosts and of VMs, Storage Xenmotion accross pools will fail. The checks run every minute. This causes the following message to appear about twice a minute on each master:
Jun 30 08:33:58 host01 xapi: [debug|host01|19 db_gc|DB GC D:c57a78cf11b9|db_gc] Number of disposable sessions in group 'external' in database (401/401) exceeds limit (400): will delete the oldest
That message only appears about every half hour when disabling the XAPI checks.
The Storage Xenmotion will fail right at the end with the following message in XenCenter:
Migrating VM 'vm01' from 'host1' to 'host2'
Internal error: Storage_interface.Internal_error("Http_client.Http_error(\"401\", \"{ frame = false; method = POST; uri = /services/SM; query = [ session_id=OpaqueRef:3cac6c44-a3c2-15b3-5d7b-137a9fe495ac ]; content_length = [ ]; transfer encoding = ; version = 1.0; cookie = [ ]; task = ; subtask_of = ; content-type = ; host = ; user_agent = xen-api-libs/1.0 }\")")
Time: 00:25:50 host1 Jun 28, 2016 4:37 PM Dismiss
When looking at xensource.log, there is a gap of 35 minutes between Async.VM.migrate_send messages. Apparently it takes 35 minutes to sync 50GB. I have attached the log lines containing Async.VM.migrate_send after the disk has been synced.
After disabling all XAPI checks, Storage Xenmotion works fine. It seems to me that either the sessions used by Storage Xenmotion should not be deleted, or that it should set up a new session when encountering a failure (401).
