I added two new drives to the array and not every time I boot I have to physically remove the drives and wait to it gets to the OS boot screen and then reattach them. If I do not do this the system will not boot. Any suggestions why this might be doing this.

Probably your BIOS boot order changed when adding the new disks, re-select the flash drive as 1st boot device.

I check it and it is set to boot from usb first.

Another possibility is that your power supply doesn't like the increased start-up load.  What kind of supply, how many drives, what CPU, motherboard, etc are you using?  It may give is a clue.

The automatic change of boot device is the usual reason, however.  When you re-checked the setting, did you still have the new drives connected?

 

 

If you're CERTAIN that the BIOS boot order is correct -- i.e. it shows your USB flash drive as the first boot device -- then you most likely have simply exceeded the capacity of your power supply.  The startup current of a hard drive is the maximum load it will "pull" -- and when you first turn on the system, you have all of these drives spinning up at once.

 

You can test whether or not it's a startup current issue by simply rebooting the system (do NOT power it off; just reboot it).  Since the drives are already spinning in this case, it should boot without issue.  If you still have the problem, then it may be something else.

 

Note that some BIOS implementations will show a USB flash drive as a "hard disk" => so even with the boot order set to USB first; you also need to check the "hard disk order" and see if the USB flash device is shown in the list of drives ... if so, move it to the first position, and that will resolve your issue.