The /proc/devices
file lists devices by major revision number and name. On my system it shows (partially):
Block devices:
259 blkext
7 loop
8 sd
9 md
11 sr
65 sd
66 sd
67 sd
68 sd
69 sd
70 sd
71 sd
128 sd
129 sd
130 sd
131 sd
132 sd
133 sd
134 sd
135 sd
253 device-mapper
254 mdp
What are all those 'sd' devices? The first one (rev. no. 8) is probably /dev/sda
but the rest of them don't show up in /dev
- there are no devices with those major revision numbers.
I do see a list of devices:
crw-rw---- 1 root tty 7, 128 Jul 29 14:15 vcsa
crw-rw---- 1 root tty 7, 129 Jul 29 14:15 vcsa1
crw-rw---- 1 root tty 7, 130 Jul 29 14:15 vcsa2
crw-rw---- 1 root tty 7, 131 Jul 29 14:15 vcsa3
crw-rw---- 1 root tty 7, 132 Jul 29 14:15 vcsa4
crw-rw---- 1 root tty 7, 133 Jul 29 14:15 vcsa5
crw-rw---- 1 root tty 7, 134 Jul 29 14:15 vcsa6
where the minor number might be a match - would /proc show minor revision numbers, and why are they called sd
. Either way, I don't see any device with no. 135
.
Could someone explain this to me?