Hi! My workplace bought a Supermicro server with a H11SSW-NT (EPYC) motherboard a year ago, and there's a small annoyance that I've been trying to find the cause for ever since:
When Linux boots up and initializes the AMD FCH SATA controller, any empty drive bay results in a DUMMY ata port, meaning, as far as I can tell, that you can't use it without rebooting after installing a drive in it. The normal writing to /sys/class/scsi_host/hostN/scan does nothing, because the whole port is disabled.
I searched through the kernel code today, and I think I've found a clue in libata-sff.c: "/* Discard disabled ports. Some controllers show their unused channels this way. Disabled ports are made dummy. */"
So apparently this is hardware-specific. My question now is mainly how common this is. The motherboard in question has a whole bunch of SlimSAS NVMe ports, of which two can instead be configured in SATA (AHCI) mode, each supporting eight drives. And second, does anyone know if there's a way to re-initialize the disabled ports after all?
When Linux boots up and initializes the AMD FCH SATA controller, any empty drive bay results in a DUMMY ata port, meaning, as far as I can tell, that you can't use it without rebooting after installing a drive in it. The normal writing to /sys/class/scsi_host/hostN/scan does nothing, because the whole port is disabled.
I searched through the kernel code today, and I think I've found a clue in libata-sff.c: "/* Discard disabled ports. Some controllers show their unused channels this way. Disabled ports are made dummy. */"
So apparently this is hardware-specific. My question now is mainly how common this is. The motherboard in question has a whole bunch of SlimSAS NVMe ports, of which two can instead be configured in SATA (AHCI) mode, each supporting eight drives. And second, does anyone know if there's a way to re-initialize the disabled ports after all?