IO Wait issues with user backups while WHM is running nightly backup
In the webinar you mentioned I/O waits are one of the bigger issues in performance, and that's in the neighborhood of my question / concern.
I have disabled (hidden) the Backup and Backup Wizard icons in all customer cPanels because of the fact that I have WHM set to run a nightly backup (to secondary hard drive in each server), and I'm concerned about users deciding to run their own Backup from cPanel at the same time that WHM nightly backups are already running from main disk to second disk.
Obviously the nightly backup puts forth I/O load spike during that time all by itself, so the main question for me is:
How safe is it to re-enable the Backup icons in cPanel for my customers, knowing that some of them with large accounts will tend to run their own Backup from cPanel at the same time while WHM is running it's nightly backups of their account at the same time?
My secondary question to that would be; if I do enable to Backup icons and a large account user decides to run a full backup of their account while WHM is already in the process of backing up their account to the second drive, does WHM/cPanel already know how to intuitively balance that out or can that scenario cause a potential serious problem (in addition I/O "spike and crawl") , or is there a better way to avoid the clash between the two?
I'm really sorry for the long question but I don't know how to put it into better words.
Thanks for the Webinar this morning, greatly appreciated!