Symptoms
You may notice the jetmongod service fails to start on Virtuozzo servers running JetBackup 5.3.9 with errors such as this:
Feb 12 23:37:00 server.hostname.tld jetmongodready[4794]: /usr/local/jetapps/usr/bin/jetmongodready: line 7: /sys/kernel/mm/transparent_hugepage/enabled: No such file or directory
Feb 12 23:37:00 server.hostname.tld systemd[1]: jetmongod.service: Control process exited, code=exited status=1
Feb 12 23:37:00 server.hostname.tld systemd[1]: jetmongod.service: Failed with result 'exit-code'.
These errors are specific to Virtuozzo and JetBackup 5.3.9.
Description
The /usr/local/jetapps/usr/bin/jetmongodready script sets various values for MongoDB, including disabling the transparent_hugepage setting. This option does not exist on Virtuozzo servers so the script exits with an error.
Workaround
JetBackup has released a patch to install the previous configuration, allowing jetmongod to start and JetBackup to function as usual:
bash <(curl -LSs https://repo.jetlicense.com/static/fixjetmongod4.4.28)
This issue is being tracked with internal case ID UPS-684.
JetBackup has more information available on their knowledge base.