My Pioneer CD/DVD R/W drive has been working fine under RH9 kernel-2.4.20-28.9smp, and works fine also on 2.4.24 from kernel.org--both using scsi-ide emulation. However, when I try running kernel 2.6.1, I get the message "/dev/cdrom is not a valid block device". I've tried building the kernel with native ide cdrom support, and also (separately) scsi-ide emulation. I get the same error no matter which type of ide cdrom support I build with. During boot, I see the message "hdc: PIONEER DVD-RW DVR-104, ATAPI CD/DVD-ROM drive", and verified that fstab includes an entry for /dev/cdrom, with /dev/cdrom symlinked either to /dev/SCD0 or /dev/HDC (depending on the cdrom driver option I selected above). I've removed the "hdc=ide-scsi" boot parameter (which 2.4 places in grub.conf for the 2.6.1 boot entry), and have tried "hdc=cdrom". In other words, whether I build the 2.6.1 kernel with ide-scsi or native ide cdrom support, I can't mount the drive--despite the fact that everything I can see during and after boot looks OK. Not sure what to try next....

Just to make sure, do you have the ide-scsi and scsi_mod modules loaded into the kernel (when you pass the hdc=ide-scsi param to the kernel) ?

Thanks for the reply! Yes, I performed an lsmod, and both mod_scsi and ide-scsi are listed.

Strange! Just check these:

[root!bhaskie.com /root]# ls -l /dev/cdrom*
lrwxrwxrwx 1 root root 11 Jan 23 16:01 /dev/cdrom -> /dev/cdrom0
lrwxrwxrwx 1 root root 8 Jan 23 16:01 /dev/cdrom0 -> /dev/hdc
lrwxrwxrwx 1 root root 9 Jan 23 16:01 /dev/cdrom1 -> /dev/scd0
[root!bhaskie.com /root]# ll /dev/scd*
brw-rw---- 1 root cdrom 11, 0 Mar 15 2002 /dev/scd0
brw-rw---- 1 root cdrom 11, 1 Mar 15 2002 /dev/scd1
[snip]

Check if /dev/scd0 etc have a "b" flag.
Also check #cdrecord -scanbus

Also, please post your /etc/fstab lines for cdrom/rw devices.

These messages are from a second smp box I have with a cd r/w drive. I decided to try 2.6.1 on it also, because I think it has a more "generic" cdrom drive (rather than the cd/dvd r/w drive we discussed before). Symptom is the same: "/dev/cdrom is not a valid block device".

I've discovered that often after booting up 2.6.1, the fstab entry for /dev/cdrom, as well as the symlink cdrom->scd0 have been removed. When this happens, I re-create them:

#ls -l /dev/cdrom*
lrwxr-xr-x 1 root root 4 Jan 23 11:53 /dev/cdrom -> scd0

#ls -l /dev/scd*
brw-rw---- 1 root disk 11, 0 Jan 30 2003 /dev/scd0
brw-rw---- 1 root disk 11, 1 Jan 30 2003 /dev/scd1
brw-rw---- 1 root disk 11, 2 Jan 30 2003 /dev/scd2
brw-rw---- 1 root disk 11, 3 Jan 30 2003 /dev/scd3
brw-rw---- 1 root disk 11, 4 Jan 30 2003 /dev/scd4
brw-rw---- 1 root disk 11, 5 Jan 30 2003 /dev/scd5
brw-rw---- 1 root disk 11, 6 Jan 30 2003 /dev/scd6
brw-rw---- 1 root disk 11, 7 Jan 30 2003 /dev/scd7

Here is fstab (after I restored it):
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hdb1 swap swap defaults 0 0
/dev/hdd4 /mnt/zip auto noauto,owner,kudzu 0 0
/dev/fd0 /mnt/floppy auto noauto,owner,kudzu 0 0
/dev/cdrom /mnt/cdrom udf,iso9660 noauto,owner,kudzu 0 0


#cdrecord -scanbus sends output to stderror:
cdrecord: No such file or directory. Cannot open '/dev/pg*'. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root.
cdrecord: For possible transport specifiers try 'cdrecord dev=help'.

For additional information, here is the output from dmesg:
Linux version 2.6.1 (root@FearNoEvil) (gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #1 SMP Fri Jan 23 11:07:43 PST 2004
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000003fff0000 (usable)
BIOS-e820: 000000003fff0000 - 000000003fff3000 (ACPI NVS)
BIOS-e820: 000000003fff3000 - 0000000040000000 (ACPI data)
BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
127MB HIGHMEM available.
896MB LOWMEM available.
found SMP MP-table at 000f4b00
hm, page 000f4000 reserved twice.
hm, page 000f5000 reserved twice.
hm, page 000f1000 reserved twice.
hm, page 000f2000 reserved twice.
On node 0 totalpages: 262128
DMA zone: 4096 pages, LIFO batch:1
Normal zone: 225280 pages, LIFO batch:16
HighMem zone: 32752 pages, LIFO batch:7
DMI 2.2 present.
ACPI: RSDP (v000 AMD2P ) @ 0x000f6470
ACPI: RSDT (v001 AMD2P AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x3fff3000
ACPI: FADT (v001 AMD2P AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x3fff3040
ACPI: MADT (v001 AMD2P AWRDACPI 0x42302e31 AWRD 0x00000000) @ 0x3fff6480
ACPI: DSDT (v001 AMD2P AWRDACPI 0x00001000 MSFT 0x0100000c) @ 0x00000000
ACPI: Local APIC address 0xfee00000
ACPI: LAPIC (acpi_id[0x00] lapic_id[0x00] enabled)
Processor #0 6:8 APIC version 16
ACPI: LAPIC (acpi_id[0x01] lapic_id[0x01] enabled)
Processor #1 6:8 APIC version 16
Using ACPI for processor (LAPIC) configuration information
Intel MultiProcessor Specification v1.4
Virtual Wire compatibility mode.
OEM ID: OEM00000 Product ID: PROD00000000 APIC at: 0xFEE00000
I/O APIC #2 Version 17 at 0xFEC00000.
Enabling APIC mode: Flat. Using 1 I/O APICs
Processors: 2
Building zonelist for node : 0
Kernel command line: ro root=LABEL=/ hdc=ide-scsi
ide_setup: hdc=ide-scsi
Initializing CPU#0
PID hash table entries: 4096 (order 12: 32768 bytes)
Detected 2134.415 MHz processor.
Using tsc for high-res timesource
Console: colour VGA+ 80x25
Memory: 1033380k/1048512k available (2185k kernel code, 14224k reserved, 626k data, 448k init, 131008k highmem)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Calibrating delay loop... 4194.30 BogoMIPS
Dentry cache hash table entries: 131072 (order: 7, 524288 bytes)
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
checking if image is initramfs...it isn't (no cpio magic); looks like an initrd
Freeing initrd memory: 217k freed
CPU: After generic identify, caps: 0383fbff c1cbfbff 00000000 00000000
CPU: After vendor identify, caps: 0383fbff c1cbfbff 00000000 00000000
CPU: CLK_CTL MSR was 6003d22f. Reprogramming to 2003d22f
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 256K (64 bytes/line)
CPU: After all inits, caps: 0383fbff c1cbfbff 00000000 00000020
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Checking 'hlt' instruction... OK.
POSIX conformance testing by UNIFIX
CPU0: AMD Athlon(tm) MP 2600+ stepping 01
per-CPU timeslice cutoff: 731.43 usecs.
task migration cache decay timeout: 1 msecs.
enabled ExtINT on CPU#0
ESR value before enabling vector: 00000000
ESR value after enabling vector: 00000000
Booting processor 1/1 eip 2000
Initializing CPU#1
masked ExtINT on CPU#1
ESR value before enabling vector: 00000000
ESR value after enabling vector: 00000000
Calibrating delay loop... 4259.84 BogoMIPS
CPU: After generic identify, caps: 0383fbff c1cbfbff 00000000 00000000
CPU: After vendor identify, caps: 0383fbff c1cbfbff 00000000 00000000
CPU: CLK_CTL MSR was 6003d22f. Reprogramming to 2003d22f
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 256K (64 bytes/line)
CPU: After all inits, caps: 0383fbff c1cbfbff 00000000 00000020
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#1.
CPU1: AMD Athlon(tm) MP stepping 01
Total of 2 processors activated (8454.14 BogoMIPS).
ENABLING IO-APIC IRQs
Setting 2 in the phys_id_present_map
...changing IO-APIC physical APIC ID to 2 ... ok.
init IO_APIC IRQs
IO-APIC (apicid-pin) 2-0, 2-5, 2-11, 2-20, 2-21, 2-22, 2-23 not connected.
..TIMER: vector=0x31 pin1=2 pin2=0
number of MP IRQ sources: 21.
number of IO-APIC #2 registers: 24.
testing the IO APIC.......................
IO APIC #2......
.... register #00: 02000000
....... : physical APIC id: 02
....... : Delivery Type: 0
....... : LTS : 0
.... register #01: 00170011
....... : max redirection entries: 0017
....... : PRQ implemented: 0
....... : IO APIC version: 0011
.... register #02: 00000000
....... : arbitration: 00
.... IRQ redirection table:
NR Log Phy Mask Trig IRR Pol Stat Dest Deli Vect:
00 000 00 1 0 0 0 0 0 0 00
01 001 01 0 0 0 0 0 1 1 39
02 001 01 0 0 0 0 0 1 1 31
03 001 01 0 0 0 0 0 1 1 41
04 001 01 0 0 0 0 0 1 1 49
05 000 00 1 0 0 0 0 0 0 00
06 001 01 0 0 0 0 0 1 1 51
07 001 01 0 0 0 0 0 1 1 59
08 001 01 0 0 0 0 0 1 1 61
09 001 01 0 0 0 0 0 1 1 69
0a 001 01 0 0 0 0 0 1 1 71
0b 000 00 1 0 0 0 0 0 0 00
0c 001 01 0 0 0 0 0 1 1 79
0d 001 01 0 0 0 0 0 1 1 81
0e 001 01 0 0 0 0 0 1 1 89
0f 001 01 0 0 0 0 0 1 1 91
10 001 01 1 1 0 1 0 1 1 99
11 001 01 1 1 0 1 0 1 1 A1
12 001 01 1 1 0 1 0 1 1 A9
13 001 01 1 1 0 1 0 1 1 B1
14 000 00 1 0 0 0 0 0 0 00
15 000 00 1 0 0 0 0 0 0 00
16 000 00 1 0 0 0 0 0 0 00
17 000 00 1 0 0 0 0 0 0 00
IRQ to pin mappings:
IRQ0 -> 0:2
IRQ1 -> 0:1
IRQ3 -> 0:3
IRQ4 -> 0:4
IRQ6 -> 0:6
IRQ7 -> 0:7
IRQ8 -> 0:8
IRQ9 -> 0:9
IRQ10 -> 0:10
IRQ12 -> 0:12
IRQ13 -> 0:13
IRQ14 -> 0:14
IRQ15 -> 0:15
IRQ16 -> 0:16
IRQ17 -> 0:17
IRQ18 -> 0:18
IRQ19 -> 0:19
.................................... done.
Using local APIC timer interrupts.
calibrating APIC timer ...
..... CPU clock speed is 2133.0044 MHz.
..... host bus clock speed is 266.0630 MHz.
checking TSC synchronization across 2 CPUs: passed.
Starting migration thread for cpu 0
Bringing up 1
CPU 1 IS NOW UP!
Starting migration thread for cpu 1
CPUS done 2
NET: Registered protocol family 16
EISA bus registered
PCI: PCI BIOS revision 2.10 entry at 0xfb130, last bus=2
PCI: Using configuration type 1
mtrr: v2.0 (20020519)
mtrr: your CPUs had inconsistent fixed MTRR settings
mtrr: probably your BIOS does not setup all CPUs.
mtrr: corrected configuration.
Linux Plug and Play Support v0.97 (c) Adam Belay
drivers/usb/core/usb.c: registered new driver usbfs
drivers/usb/core/usb.c: registered new driver hub
PCI: Probing PCI hardware
PCI: Probing PCI hardware (bus 00)
PCI: Using IRQ router default [1022/700c] at 0000:00:00.0
PCI->APIC IRQ transform: (B0,I9,P0) -> 17
PCI->APIC IRQ transform: (B0,I9,P1) -> 18
PCI->APIC IRQ transform: (B0,I9,P2) -> 19
PCI->APIC IRQ transform: (B1,I5,P0) -> 17
PCI->APIC IRQ transform: (B2,I0,P3) -> 19
PCI->APIC IRQ transform: (B2,I4,P0) -> 16
PCI->APIC IRQ transform: (B2,I9,P0) -> 17
apm: BIOS version 1.2 Flags 0x07 (Driver version 1.16ac)
apm: disabled - APM is not SMP safe.
Starting balanced_irq
highmem bounce pool size: 64 pages
VFS: Disk quotas dquot_6.5.1
Initializing Cryptographic API
BIOS failed to enable PCI standards compliance, fixing this error.
pty: 256 Unix98 ptys configured
Linux agpgart interface v0.100 (c) Dave Jones
[drm] Initialized tdfx 1.0.0 20010216 on minor 0
[drm] Initialized radeon 1.9.0 20020828 on minor 1
Using anticipatory io scheduler
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
RAMDISK driver initialized: 16 RAM disks of 4096K size 1024 blocksize
Intel(R) PRO/100 Network Driver - version 2.3.30-k1
Copyright (c) 2003 Intel Corporation

e100: selftest OK.
e100: eth0: Intel(R) PRO/100 Network Connection
Hardware receive checksums enabled

Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
AMD7441: IDE controller at PCI slot 0000:00:07.1
AMD7441: chipset revision 4
AMD7441: not 100% native mode: will probe irqs later
AMD7441: 0000:00:07.1 (rev 04) UDMA100 controller
ide0: BM-DMA at 0xe000-0xe007, BIOS settings: hdaMA, hdbMA
ide1: BM-DMA at 0xe008-0xe00f, BIOS settings: hdcMA, hddMA
hda: WDC WD400BB-00AUA1, ATA DISK drive
hdb: WDC WD2500JB-00EVA0, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hdc: LG CD-RW CED-8080B, ATAPI CD/DVD-ROM drive
hdd: IOMEGA ZIP 250 ATAPI Floppy, ATAPI FLOPPY drive
ide1 at 0x170-0x177,0x376 on irq 15
hda: max request size: 128KiB
hda: 78165360 sectors (40020 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100)
hda: hda1 hda2
hdb: max request size: 1024KiB
hdb: 488397168 sectors (250059 MB) w/8192KiB Cache, CHS=30401/255/63, UDMA(100)
hdb: hdb1 hdb2
ide-floppy driver 0.99.newide
hdd: No disk in drive
hdd: 0kB, 0/64/32 CHS, 4096 kBps, 512 sector size, 2941 rpm
mice: PS/2 mouse device common for all mice
serio: i8042 AUX port at 0x60,0x64 irq 12
input: PS/2 Logitech Mouse on isa0060/serio1
serio: i8042 KBD port at 0x60,0x64 irq 1
input: AT Translated Set 2 keyboard on isa0060/serio0
EISA: Probing bus 0 at eisa0
NET: Registered protocol family 2
IP: routing cache hash table of 8192 buckets, 64Kbytes
TCP: Hash tables configured (established 262144 bind 65536)
NET: Registered protocol family 1
NET: Registered protocol family 17
RAMDISK: Compressed image found at block 0
VFS: Mounted root (ext2 filesystem).
kjournald starting. Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
Freeing unused kernel memory: 448k freed
Real Time Clock Driver v1.12
drivers/usb/core/usb.c: registered new driver hiddev
drivers/usb/core/usb.c: registered new driver hid
drivers/usb/input/hid-core.c: v2.0:USB HID core driver
EXT3 FS on hdb2, internal journal
Adding 2530228k swap on /dev/hdb1. Priority:-1 extents:1
kjournald starting. Commit interval 5 seconds
EXT3 FS on hda1, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
SCSI subsystem initialized
ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX as device
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Vendor: LG Model: CD-RW CED-8080B Rev: 1.05
Type: CD-ROM ANSI SCSI revision: 02
kudzu: numerical sysctl 1 23 is obsolete.
parport0: PC-style at 0x378 [PCSPP,TRISTATE]
parport0: cpp_daisy: aa5500ff(98)
parport0: assign_addrs: aa5500ff(98)
parport0: Printer, HEWLETT-PACKARD DESKJET 895C
e100: eth0 NIC Link is Up 100 Mbps Full duplex
rpc.rquotad: numerical sysctl 5 16 8 is obsolete.
atkbd.c: Unknown key released (translated set 2, code 0x7a on isa0060/serio0).
atkbd.c: Unknown key released (translated set 2, code 0x7a on isa0060/serio0).
nfs warning: mount version older than kernel

Lastly, I'm sending you via email the whole dang .config file with which I built the kernel (it's too long to be included here).

I really appreciate your looking at this!

Jim Jensen

Success, finally. Initially I built the 2.6.1 kernel with ATAPI cdrom support only, then tried SCSI emulation only, then both. Nothing worked. I decided to try ATAPI cdrom support only again, and for some reason I don't understand, things began working properly. Thanks again to Bhaskar for his help.

Hi,
Will look into the config file and other output and try to figure out what the problem was. Till then, enjoy the 2.6 kernel!

jwjensen

Would you please tell what are the changes you made to make work? I got the same problem.

mount: /dev/cdrom is not a valid block device

Problem solved. I found the solution by trial and error. I just deleted the hdc=ide-scsi from my grub file and it did work fine. I came to this idea after knowing that kernel 2.6.0 does not need the scsi emulation to write to the cd. My DVD rom is mounting correctly.