Multiple UPSes

OK, so now for a problem that probably only affects me. I have multiple UPSes in my server closet. A large one (APC BackUPS XS-1300 LCD) for most of the computers in the closet and a mid-sized one (APC BackUPS XS-900) for the computers in my office. I have a long wire running through the floor into my office. Why not put the mid-sized one in the office itself? Because it has a noisy fan.

Both these USPes are connected via USB to one computer. This computer assigns nearly randomly the device name, based on where I've plugged them into a USB hub. This resulted in the computers in the basement thinking they were on the 900 and my office thinking it was on the 1300. Not acceptable.

Using lsusb, I see the UPSes are at 2:5 and 2:4

# lsusb
Bus 004 Device 001: ID 0000:0000  
Bus 003 Device 001: ID 0000:0000  
Bus 005 Device 001: ID 0000:0000  
Bus 001 Device 001: ID 0000:0000  
Bus 002 Device 005: ID 051d:0002 American Power Conversion Uninterruptible Power Supply
Bus 002 Device 002: ID 05e3:0604 Genesys Logic, Inc. USB 1.1 Hub
Bus 002 Device 001: ID 0000:0000  
Bus 002 Device 004: ID 051d:0002 American Power Conversion Uninterruptible Power Supply

Again with lsusb, I can find the serial number:

# lsusb -v -s 2:5
Bus 002 Device 005: ID 051d:0002 American Power Conversion Uninterruptible Power Supp
ly
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x051d American Power Conversion  
  idProduct          0x0002 Uninterruptible Power Supply
  bcdDevice            1.06
  iManufacturer           3 American Power Conversion
  iProduct                1 Back-UPS XS  900 FW:830.E8 .D USB FW:E8 
  iSerial                 2 BB0842016813  
... SNIP ...

Another way to get the same info:

# udevinfo -a -p /class/usb_device/usbdev2.5
  looking at device '/class/usb_device/usbdev2.5':
    KERNEL=="usbdev2.5"
    SUBSYSTEM=="usb_device"
    SYSFS{dev}=="189:132"

  looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.3':
    ID=="2-1.3"
    BUS=="usb"
    DRIVER=="usb"
    SYSFS{configuration}==""
    SYSFS{serial}=="BB0842016813  "
    SYSFS{product}=="Back-UPS XS  900 FW:830.E8 .D USB FW:E8 "
    SYSFS{manufacturer}=="American Power Conversion"
    SYSFS{maxchild}=="0"
    SYSFS{version}==" 1.10"
... SNIP ...

Then I created some custom udev rules in /etc/udev/rules.d/99-apc.rules:

KERNEL=="hiddev*", SYSFS{serial}=="BB0842016813*", NAME="apc900"
KERNEL=="hiddev*", SYSFS{serial}=="JB0741003708*", NAME="apc1300"

I could also have used SYSFS{product} for matching, but the serial number uniquely defines these UPSes. I need the * for globbing because the serial number is padded with spaces, as can be seen in the udevinfo output.

Next reload the udev db:

# udevcontrol reload_rules
# udevtrigger
# ls -l /dev/apc*
crw------- 1 root root 180, 97 Oct  5 12:53 /dev/apc1300
crw------- 1 root root 180, 96 Oct  5 12:53 /dev/apc900

YAY!