This is a 600GB RAID6 array in degraded mode across 2x300GB PATA IDE drives, one partition as /dev/md0, ext3 file system. Formats ok. Files wrote to it ok (about 75% full). A few dozen out of a few thousand of files have a bad md5sum when compared to original on an 400GB SATA disc with NTFS or FAT32 (formatted in Linux). So far when running md5sum on the files, 2 files (maybe more as I proceed) enter a D state (uninterruptable), but there's no disc I/O, no activity, and the process hangs indefinitely, even if the parent is killed. If I try to md5sum the file again, hang. If I reboot and try, hang. It's consistent which files it hangs on, so far only 2. Ideas? When I finish moving data from SATA to PATA then I will bring the SATA drives in to the array.
I run a command sequence such as this to generate md5sums, then diff source and target MD5SUM files:
cd /mnt/md0/path1
find path2/dir -print0 | xargs -0 -n 1 md5sum >> /mnt/md0/MD5SUM.md0_path2_dir.md5 2> /dev/null &
tail -f /mnt/md0/MD5SUM.md0_path2_dir.md5 &
Any ideas?

USB 3.0 Flash Drive 32GB 64GB 128GB Memory Stick Thumb Stick Lot Pack
$826.09
Microsoft Office 2021 Pro Plus USB for 1PC Windows 10 & 11
$62.50
TF/SD Card Adapter Camera Reader Android Type-c For iPhone17 Pro Max Plusm lot
$573.98
Wholesale 5/10/100PCS 1GB 2GB 4GB 8GB 16GB 32GB USB 2.0 Flash Drive Memory Stick
$378.00
$300.00
128GB (4x32GB) SK hynix DDR4 PC4-2666V RDIMM ECC Server Ram HMA84GR7CJR4N-VK
$799.00
*LOT OF 4* 32GB SK Hynix HMA84GR7MFR4N-TF DDR4-2133 ECC RDIMM PC4-17000 2Rx4
$674.99
USB 3.0 Micro SD SDHC TF Card Reader Memory Adapter for PC Laptop Camera lot
$3.75
Windows 11 Pro Install/Recovery/Repair USB Flash Drive
$35.00
LOT OF 3 Micron 16GB 2Rx8 PC4-3200AA DDR4 ECC Server Memory
$255.00