Similar to other's problems, the USB/USB2 either leaves the file operations hanging indefinetely or ends in a kernel panic.
Tue Aug 17 00:40:46 2004
panic(cpu 0): ext2_cmap: allocation requested inside a block (possible filesystem corruption): qbmask=4095, inode=557058, offset=390656, blkoff=1536
Latest stack backtrace for cpu 0:
0x000836E4 0x00083BC8 0x0001EDA4 0x20E066A8 0x000B82DC 0x000BBACC 0x000B8A08 0x000BADC0
0x000BA5E0 0x20E003F8 0x000CDFCC 0x0022150C 0x00221324 0x002452B4 0x00094200 0x00090009
Kernel loadable modules in backtrace (with dependencies):
Proceeding back via exception chain:
Exception state (sv=0x20ECB780)
PC=0x9000EACC; MSR=0x0000F030; DAR=0x16BAA008; DSISR=0x40000000; LR=0x9370A2E8; R1=0xF01826F0; XCP=0x00000030 (0xC00 - System call)
Darwin Kernel Version 7.5.0:
Thu Aug 5 19:26:16 PDT 2004; root:xnu/xnu-517.7.21.obj~3/RELEASE_PPC
Yes, this is a known problem with some USB drives. I'm 80% sure it is a hardware problem, since plugging the drive in through some other interface (FW, IDE) or even using a different USB enclosure makes the problem disappear. Right now, ext2 and USB is a crap shoot. My suggesstion is to use FW if at all possible. Most enclosure sold today are dual USB/FW.