• Fedora Core 10
• 8GB RAM
• ASUS P5KC Motherboard
• 36Gb WD Raptor on SATA 0
• 2 250Gb WD in mirrored array on SATA 2 & 3

I would see all kinds of wierd behavior with my filesystems.  /dev/sda would all of a sudden just switch into read only mode.  There were also really long delays in doing disk read/writes.  My drive would be loading then just stop all activity for 1-2 minutes then continue loading.

I checked /var/log/messages and saw this sequence of errors repeating themselves almost every 10 seconds.

Apr 28 08:13:40 falcon kernel: ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
Apr 28 08:13:40 falcon kernel: ata3.00: configured for UDMA/100
Apr 28 08:13:40 falcon kernel: ata3: EH complete
Apr 28 08:13:40 falcon kernel: sd 2:0:0:0: [sda] 72303840 512-byte hardware sectors (37020 MB)
Apr 28 08:13:40 falcon kernel: sd 2:0:0:0: [sda] Write Protect is off
Apr 28 08:13:40 falcon kernel: sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
Apr 28 08:13:40 falcon kernel: ata3.00: limiting speed to UDMA/33:PIO4
Apr 28 08:13:40 falcon kernel: ata3.00: exception Emask 0x10 SAct 0x0 SErr 0x400100 action 0x6
Apr 28 08:13:40 falcon kernel: ata3.00: BMDMA stat 0x26
Apr 28 08:13:40 falcon kernel: ata3: SError: { UnrecovData Handshk }
Apr 28 08:13:40 falcon kernel: ata3.00: cmd ca/00:a8:69:b6:29/00:00:00:00:00/e3tag 0 dma 86016 out
Apr 28 08:13:40 falcon kernel: res 51/84:00:10:b7:29/84:00:03:00:00/e3 Emask 0x30 (host bus error)
Apr 28 08:13:40 falcon kernel: ata3.00: status: { DRDY ERR }
Apr 28 08:13:40 falcon kernel: ata3.00: error: { ICRC ABRT }
Apr 28 08:13:40 falcon kernel: ata3: hard resetting link

After looking up DRDY ERR I finally found some posts mentioning bad SATA cables.  I replaced the SATA cable on my boot drive /dev/sda and now I have no more issues.  It appears my SATA cable was bad.