gstripe oder graid3 on USB-Sticks

[Raphael H. Becker]

Hello *,

today I bought 3 USB sticks to find out, if there's something to play 
with GEOM on it. My FreeBSD ist 6.2-RC1.

umass0: SanDisk Corporation Cruzer Micro, rev 2.00/0.10, addr 3
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <SanDisk Cruzer Micro 0.1> Removable Direct Access SCSI-2 device 
da0: 40.000MB/s transfers
da0: 977MB (2001888 512 byte sectors: 64H 32S/T 977C)


# graid3 status sticks
        Name    Status  Components
raid3/sticks  COMPLETE  da1
                        da2
                        da0


I newfs'd this stick-RAID3 and dd'd about 1G /dev/zero into a file,
gives me  about 8MB/sec.

Trying to read this file using dd seems to deadlock the device, dd is'nt
interruptable by SIGHUP (^C) until removing one stick of the mounted
raid3, which causes an error. umount /mnt works. 

umass0: BBB reset failed, IOERROR
umass0: BBB bulk-in clear stall failed, IOERROR
umass0: BBB bulk-out clear stall failed, IOERROR
umass0: BBB reset failed, IOERROR
umass0: BBB bulk-in clear stall failed, IOERROR
umass0: BBB bulk-out clear stall failed, IOERROR
umass0: at uhub4 port 4 (addr 3) disconnected
(da0:umass-sim0:0:0:0): lost device
GEOM_RAID3: Device sticks: provider da0 disconnected.
(da0:dead_sim0:0:0:0): Synchronize cache failed, status == 0x8, scsi status == 0x0
(da0:dead_sim0:0:0:0): removing device entry
GEOM_RAID3: Request failed (error=22). da0[READ(offset=12872192, length=65536)]
umass0: detached


After reinserting the stick, the automatic rebuild begins and finishes
successfully:


umass0: SanDisk Corporation Cruzer Micro, rev 2.00/0.10, addr 3
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <SanDisk Cruzer Micro 0.1> Removable Direct Access SCSI-2 device 
da0: 40.000MB/s transfers
da0: 977MB (2001888 512 byte sectors: 64H 32S/T 977C)
GEOM_RAID3: Device sticks: provider da0 detected.
GEOM_RAID3: Device sticks: rebuilding provider da0.
GEOM_RAID3: Device sticks: rebuilding provider da0 finished.
GEOM_RAID3: Device sticks: provider da0 activated.


Remounting / umount works:
root at daemon:~# mount /dev/raid3/stickss1 /mnt/
root at daemon:~# mount
/dev/raid3/stickss1 on /mnt (ufs, local)
root at daemon:~# umount


... but fsck the umounted filesystem 

root at daemon:~# fsck /dev/raid3/stickss1 
fsck: Could not determine filesystem type


Any idea about this?
Is this geom-specific? Or USB-stick related?

Can anyone else reproduce this behaviour (lock when reading)?