On Sun, 2011-10-16 at 20:15 -0500, Chris Adams wrote:
The problem with enumerating devices by HBA/bus/ID/LUN is that today's storage is more dynamic. USB ports are "SCSI" (protocol); how do you number those? IIRC USB ports on a hub are not deterministically ordered, so a flash card reader on a hub may come before a thumb drive on one boot and after on the next.
I would have gone down the route of calling USB devices with a usb device name. So a USB device doesn't become sda and shuffle device names around for *other* devices.
And I would have left IDE style devices as hd, SCSI as sd, SATA as sa, and so on, and so forth...
That way when I have a computer with an internal IDE drive, an external USB, and an external SATA, I could tell them instantly apart from each other as they would be /dev/hda, /dev/usb1, /dev/sa1. Rather than /dev/sda, /dev/sdb, and /dev/sdc, where I could guess that the internal drive was *probably* /dev/sda, but could never guess what either of the other two were.