Greetings all. I would appreciate any incite that you can give me with this problem. I am sure that you have visited this issue in the past, but I have been unable to find a resolution. The symptoms are ad1: TIMEOUT - READ_DMA retrying (2 retries left) LBA=10027551 ad0: WARNING - removed from configuration ad1: WARNING - removed from configuration ata0-slave: FAILURE - READ_DMA timed out After these messages the machine is unusable until it is power cycled. The machine can is described by dmesg below, but here is some history. The machine has been running FreeBSD 4.8 - 4.10 for the last several years with two disks on the ATA0 controller. (ad0= Maxtor 51024H2 10GB, ad1=WD400BB 40GB) I finally decided it was time to move to 5.x release. I also decided it was time to upgrade the disks I used a Maxtor 20GB for ad0 and WD2500JB for ad1. The Maxtor disk has been used before but the WD is brand new. The machine is a 733 MHz Compaq Deskpro EN (Intel 815e chipset with an ICH 2 ata controller). I have turned off all power management functions in the CMOS. I am currently running the GENERIC Kernel as taken from the 5.4 ISO install. I upgraded to p4 but it did not help my situation so I backed off. I have searched high and low and have found a suggestion of adding a command to the /boot/loader.conf to no avail. I do not believe that the issue is the ata controller, however, it could have to do with compatibility with the 250GB WD drive with FreeBSD. I have not used the WD before but I have tested it with Western Digital's Data Lifeguard Diagnostics as it was installed in the box for both communication and media errors with no errors found. The issue seems to occur when the system has been idle for some time (an hour or so). Below is my dmesg output. I do not want to reload 4.10 to have a working system. Thanks for the help. Ray Copyright (c) 1992-2005 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD 5.4-RELEASE #0: Sun May 8 10:21:06 UTC 2005 root@harlow.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC Timecounter "i8254" frequency 1193182 Hz quality 0 CPU: Intel Pentium III (730.90-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x683 Stepping = 3 Features=0x383fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA, CMOV,PAT,PSE36,MMX,FXSR,SSE> real memory = 535822336 (511 MB) avail memory = 514658304 (490 MB) MPTable: <COMPAQ Deskpro > ioapic0: Changing APIC ID to 8 ioapic0: Assuming intbase of 0 ioapic0 <Version 2.0> irqs 0-23 on motherboard npx0: <math processor> on motherboard npx0: INT 16 interface cpu0 on motherboard pcib0: <MPTable Host-PCI bridge> pcibus 0 on motherboard pci0: <PCI bus> on pcib0 agp0: <Intel 82815 (i815 GMCH) SVGA controller> mem 0x40500000-0x4057ffff,0x44000000-0x47ffffff irq 16 at device 2.0 on pci0 pcib1: <MPTable PCI-PCI bridge> at device 30.0 on pci0 pci2: <PCI bus> on pcib1 fxp0: <Intel 82801BA/CAM (ICH2/3) Pro/100 Ethernet> port 0x1000-0x103f mem 0x40100000-0x40100fff irq 20 at device 8.0 on pci2 miibus0: <MII bus> on fxp0 inphy0: <i82562EM 10/100 media interface> on miibus0 inphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto fxp0: Ethernet address: 00:50:8b:d8:70:af fxp1: <Intel 82559 Pro/100 Ethernet> port 0x1040-0x107f mem 0x40000000-0x400fffff,0x40200000-0x40200fff irq 18 at device 9.0 on pci2 miibus1: <MII bus> on fxp1 inphy1: <i82555 10/100 media interface> on miibus1 inphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto fxp1: Ethernet address: 00:d0:b7:0f:a7:f4 isab0: <PCI-ISA bridge> at device 31.0 on pci0 isa0: <ISA bus> on isab0 atapci0: <Intel ICH2 UDMA100 controller> port 0x2460-0x246f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 31.1 on pci0 ata0: channel #0 on atapci0 ata1: channel #1 on atapci0 uhci0: <Intel 82801BA/BAM (ICH2) USB controller USB-B> port 0x2440-0x245f irq 23 at device 31.4 on pci0 usb0: <Intel 82801BA/BAM (ICH2) USB controller USB-B> on uhci0 usb0: USB revision 1.0 uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered pcm0: <Intel ICH2 (82801BA)> port 0x2400-0x243f,0x2000-0x20ff irq 17 at device 31.5 on pci0 pcm0: <Analog Devices AD1885 AC97 Codec> orm0: <ISA Option ROMs> at iomem 0xe0000-0xeffff,0xcb000-0xd87ff,0xca000-0xcafff,0xc0000-0xc9fff on isa0 pmtimer0 on isa0 atkbdc0: <Keyboard controller (i8042)> at port 0x64,0x60 on isa0 atkbd0: <AT Keyboard> irq 1 on atkbdc0 kbd0 at atkbd0 psm0: <PS/2 Mouse> irq 12 on atkbdc0 psm0: model IntelliMouse, device ID 3 fdc0: <Enhanced floppy controller> at port 0x3f0-0x3f5 irq 6 drq 2 on isa0 fd0: <1440-KB 3.5" drive> on fdc0 drive 0 ppc0: <Parallel port> at port 0x378-0x37f irq 7 on isa0 ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode ppc0: FIFO with 16/16/13 bytes threshold ppbus0: <Parallel port bus> on ppc0 plip0: <PLIP network interface> on ppbus0 lpt0: <Printer> on ppbus0 lpt0: Interrupt-driven port ppi0: <Parallel I/O> on ppbus0 sc0: <System console> at flags 0x100 on isa0 sc0: VGA <16 virtual consoles, flags=0x300> sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0 sio0: type 16550A sio1 at port 0x2f8-0x2ff irq 3 on isa0 sio1: type 16550A vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0 unknown: <PNP0401> can't assign resources (port) unknown: <PNP0501> can't assign resources (port) unknown: <PNP0501> can't assign resources (port) unknown: <PNP0700> can't assign resources (port) unknown: <PNP0303> can't assign resources (port) unknown: <PNP0f13> can't assign resources (irq) Timecounter "TSC" frequency 730899496 Hz quality 800 Timecounters tick every 10.000 msec ad0: 19092MB <MAXTOR 6L020J1/A93.0500> [38792/16/63] at ata0-master UDMA100 ad1: 238475MB <WDC WD2500JB-00GVA0/08.02D08> [484521/16/63] at ata0-slave UDMA100 acd0: CDROM <LTN323/DQ19> at ata1-master PIO4 pcm0: measured ac97 link rate at 55931 Hz Mounting root from ufs:/dev/ad0s1a WARNING: / was not properly dismounted WARNING: /home was not properly dismounted WARNING: /usr was not properly dismounted WARNING: /usr/local was not properly dismounted WARNING: /var was not properly dismounted I