BIG udev problem on pogoplug v2 arm5te

[celtus]

My test system boots archlinux from an extenal usb drive. Since uboot mandates /dev/sda as the boot device, this drive spins up as /dev/sda and all is well. When I plug in a second usb external drive (which would be for media, for example), the original usb boot drive is removed and comes in with a different designator when udev settles.

This is the portion of dmesg that shows the initial usb boot device:

$this->bbcode_second_pass_code('', '[ 12.922857] Waiting 10sec before mounting root device...
[ 14.060452] scsi0 : usb-storage 1-1.1:1.0
[ 15.063537] scsi 0:0:0:0: Direct-Access Maxell HDD PQ: 0 ANSI: 4
[ 15.064247] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 15.066223] sd 0:0:0:0: [sda] 117210240 512-byte logical blocks: (60.0 GB/55.8 GiB)
[ 15.072587] sd 0:0:0:0: [sda] Write Protect is off
[ 15.072601] sd 0:0:0:0: [sda] Mode Sense: 38 00 00 00
[ 15.078961] sd 0:0:0:0: [sda] No Caching mode page present
[ 15.084472] sd 0:0:0:0: [sda] Assuming drive cache: write through
[ 15.104709] sd 0:0:0:0: [sda] No Caching mode page present
[ 15.110240] sd 0:0:0:0: [sda] Assuming drive cache: write through
[ 16.441966] sda: sda1 sda2
[ 16.456586] sd 0:0:0:0: [sda] No Caching mode page present
[ 16.462127] sd 0:0:0:0: [sda] Assuming drive cache: write through
[ 16.468293] sd 0:0:0:0: [sda] Attached SCSI disk')

This is what udevadm monitor sees when a second external usb drive is plugged in:

$this->bbcode_second_pass_code('', '[root@alarm ~]# udevadm monitor
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[142.082801] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/bsg/0:0:0:0 (bsg)
KERNEL[142.083921] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_generic/sg0 (scsi_generic)
KERNEL[142.085587] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_device/0:0:0:0 (scsi_device)
UDEV [142.085780] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/bsg/0:0:0:0 (bsg)
KERNEL[142.085888] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_disk/0:0:0:0 (scsi_disk)
KERNEL[142.087963] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda/sda2 (block)
UDEV [142.088815] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_generic/sg0 (scsi_generic)
UDEV [142.099962] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_device/0:0:0:0 (scsi_device)
UDEV [142.101505] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/scsi_disk/0:0:0:0 (scsi_disk)
UDEV [142.103675] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda/sda2 (block)
KERNEL[142.276480] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda/sda1 (block)
[b]UDEV [142.278527] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda/sda1 (block)[/b]
KERNEL[142.279864] remove /devices/virtual/bdi/8:0 (bdi)
UDEV [142.280947] remove /devices/virtual/bdi/8:0 (bdi)
KERNEL[142.282658] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda (block)
KERNEL[142.283162] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0 (scsi)
UDEV [142.284665] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0/block/sda (block)
KERNEL[142.285512] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/scsi_host/host0 (scsi_host)
UDEV [142.286396] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/target0:0:0/0:0:0:0 (scsi)
KERNEL[142.287366] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0 (scsi)
KERNEL[142.288129] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0 (usb)
UDEV [142.289483] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0/scsi_host/host0 (scsi_host)
KERNEL[142.290197] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/usb_device/usbdev1.3 (usb_device)
KERNEL[142.290720] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1 (usb)
UDEV [142.292138] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host0 (scsi)
UDEV [142.302799] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0 (usb)
UDEV [142.304312] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/usb_device/usbdev1.3 (usb_device)
UDEV [142.305826] remove /devices/platform/orion-ehci.0/usb1/1-1/1-1.1 (usb)
KERNEL[142.803934] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1 (usb)
KERNEL[142.830172] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0 (usb)
KERNEL[142.850643] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1 (scsi)
KERNEL[142.850769] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/scsi_host/host1 (scsi_host)
KERNEL[142.852115] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/usb_device/usbdev1.4 (usb_device)
UDEV [142.853895] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1 (usb)
UDEV [142.856244] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/usb_device/usbdev1.4 (usb_device)
UDEV [142.857827] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0 (usb)
UDEV [142.859067] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1 (scsi)
UDEV [142.868586] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/scsi_host/host1 (scsi_host)
KERNEL[143.932573] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0 (scsi)
KERNEL[143.932716] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0 (scsi)
KERNEL[143.932816] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_disk/1:0:0:0 (scsi_disk)
KERNEL[143.932913] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_device/1:0:0:0 (scsi_device)
UDEV [143.934896] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0 (scsi)
UDEV [143.938199] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0 (scsi)
KERNEL[143.938352] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_generic/sg0 (scsi_generic)
UDEV [143.938460] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_device/1:0:0:0 (scsi_device)
KERNEL[143.942876] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/bsg/1:0:0:0 (bsg)
UDEV [143.943592] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_generic/sg0 (scsi_generic)
UDEV [143.945479] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/scsi_disk/1:0:0:0 (scsi_disk)
UDEV [143.948076] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/bsg/1:0:0:0 (bsg)
KERNEL[143.973182] add /devices/virtual/bdi/8:16 (bdi)
UDEV [143.977679] add /devices/virtual/bdi/8:16 (bdi)
KERNEL[144.107786] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb (block)
KERNEL[144.107938] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb/sdb1 (block)
KERNEL[144.108057] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb/sdb2 (block)
UDEV [145.237051] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb (block)
[b]UDEV [145.503618] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb/sdb1 (block)[/b]
UDEV [145.506504] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.1/1-1.1:1.0/host1/target1:0:0/1:0:0:0/block/sdb/sdb2 (block)
KERNEL[149.495087] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4 (usb)
KERNEL[149.504358] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0 (usb)
KERNEL[149.513641] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2 (scsi)
KERNEL[149.513766] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/scsi_host/host2 (scsi_host)
KERNEL[149.514743] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/usb_device/usbdev1.5 (usb_device)
UDEV [149.723776] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4 (usb)
UDEV [149.725948] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0 (usb)
UDEV [149.727432] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2 (scsi)
UDEV [149.739231] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/scsi_host/host2 (scsi_host)
UDEV [149.741713] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/usb_device/usbdev1.5 (usb_device)
KERNEL[150.540182] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0 (scsi)
KERNEL[150.540325] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0 (scsi)
UDEV [150.541935] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0 (scsi)
KERNEL[150.543415] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_disk/2:0:0:0 (scsi_disk)
KERNEL[150.543545] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_device/2:0:0:0 (scsi_device)
UDEV [150.545708] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0 (scsi)
KERNEL[150.545876] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_generic/sg1 (scsi_generic)
UDEV [150.548259] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_device/2:0:0:0 (scsi_device)
KERNEL[150.551332] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/bsg/2:0:0:0 (bsg)
KERNEL[150.556052] add /devices/virtual/bdi/8:32 (bdi)
UDEV [150.556536] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_disk/2:0:0:0 (scsi_disk)
UDEV [150.556943] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/bsg/2:0:0:0 (bsg)
UDEV [150.567043] add /devices/virtual/bdi/8:32 (bdi)
UDEV [150.569582] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/scsi_generic/sg1 (scsi_generic)
KERNEL[150.638618] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/block/sdc (block)
[b]KERNEL[150.638766] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/block/sdc/sdc1 (block)[/b]
UDEV [150.641697] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/block/sdc (block)
UDEV [150.643439] add /devices/platform/orion-ehci.0/usb1/1-1/1-1.4/1-1.4:1.0/host2/target2:0:0/2:0:0:0/block/sdc/sdc1 (block)')

There are only two devices, and now they are named /dev/sdb and /dev/sdc - /dev/sda is gone.

Subsequent attempts to run commands result in Input/output errors, such as this:

$this->bbcode_second_pass_code('', '[root@alarm ~]# udevadm monitor
-bash: /usr/bin/udevadm: Input/output error')

I am admittedly old-school, and have never cared much for udev. Can anyone help with a solution to this problem? A NAS that can't have drives attached is pretty useless...

Thanks in advance!