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?

🔀 Juniper Networks EX2300-C-12P 12× Gigabit PoE+ • 2× 10G SFP+ Compact Switch ⚡
$109.99
Juniper EX2300 12-Port Gigabit PoE+ Managed Network Switch P/N: EX2300-C-12P
$149.99
Juniper Networks EX3400-24T 24-Port Ethernet Switch w/Power Cord
$174.99
Juniper EX3400-24P 24-Port PoE+ GbE + 4-Port 1/10Gb SFP Switch
$245.00
JUNIPER QFX5120-48Y-AFO 48x 10/25GbE SFP28 8x 40/100GbE Network Switch Dual PSU
$6998.00
Juniper Networks QFX-SFP-DAC-7MA to Brocade (Formerly) XBR-TWX-0701 Comp TAA
$196.99
Juniper Networks AP33-US Indoor Wifi6 (US Version) 5GHz: 4x4:4; 2.99
$24.99
Juniper MX204 +JUNOS and Dual Power Supply
$7299.99
Juniper Networks Mist Wireless Access Points, Model AP45
$59.99
Juniper Networks EX2300-48P 48-Port Gigabit PoE Managed Ethernet Switch
$79.99