I have a machine with a lot of disks, and an extra SAS controller in HBA mode. This seems to cause Linux to think for at least 8-10 seconds once in initramfs before the disks actually appear. The timeout for disk detection is 10 seconds. This causes BTRFS/MDADM/etc fail to mount a RAID1 that I have in my system, dropping me to an emergency shell from where I can actually mount the disks and continue just fine.
My question is, how do I increase this timeout at boot from 10 seconds? Is it in systemd? is it in udev? somewhere else? I'm not sure where to start looking, and googling about this problem mostly seems to yield people looking to raise the I/O timeout or some other (scsi/lun/etc) timeouts, but I'm not looking for that.