If I had to guess, I'd say it was a timing issue. The CD-ROM that doesn't work is taking slightly longer to discover and maybe longer to get ready. Most "LiveCD" type distros I've seen load an initrd which has a wait-loop in it to wait for the real root device to appear before mount/chroot. Matt On Tue, Dec 4, 2012 at 2:13 PM, Chris Friesen <chris.friesen@xxxxxxxxxxx> wrote: > > Hi, > > I hope this is the right place to send this, if not please let me know where > would be more appropriate. > > We distribute a 2.6.27-based software load on bootable DVD. It's intended > to boot on a system that has no internal DVD drive, so we use USB DVD drives. > > With most drives we have no problems, but I've received a complaint from > someone that has a drive that won't boot our software and I can't figure > out why. The same drive will boot a RHEL install disc. > > Any suggestions you might have would be great. > > > The non-working drive is a Sony, and the relevant boot logs look like this: > > usb 1-1.6.1: new high speed USB device using ehci_hcd and address 5 > scsi9 : usb-storage 1-1.6.1:1.0 > scsi 9:0:0:0: Direct-Access Generic Ultra HS-COMBO 2.01 PQ: 0 ANSI: 0 > sd 9:0:0:0: Attached scsi generic sg2 type 0 > sd 9:0:0:0: [sdc] Attached SCSI removable disk > scsi 9:0:0:1: Direct-Access Generic Ultra HS-SD/MMC2 2.01 PQ: 0 ANSI: 0 > sd 9:0:0:1: Attached scsi generic sg3 type 0 > sd 9:0:0:1: [sdd] Attached SCSI removable disk > scsi 8:0:0:0: CD-ROM SONY DVD RW DRU-840A SS01 PQ: 0 ANSI: 0 > sr0: scsi3-mmc drive: 12x/40x writer dvd-ram cd/rw xa/form2 cdda tray > Uniform CD-ROM driver Revision: 3.20 > sr 8:0:0:0: Attached scsi generic sg4 type 5 > md: Waiting for all devices to be available before autodetect > md: If you don't use raid, use raid=noautodetect > md: Autodetecting RAID arrays. > md: Scanned 0 and added 0 devices. > md: autorun ... > md: ... autorun DONE. > VFS: Cannot open root device "sr0" or unknown-block(11,0) > Please append a correct "root=" boot option; here are the available partitions: > 0810 879087384 sdb driver: sd > 0800 879087384 sda driver: sd > 0b00 1048575 sr0 driver: sr > VFS: Unable to mount root fs on unknown-block(11,0) > User configuration error - no valid root filesystem found > > > I'm confused why it can't open sr0 when it clearly lists sr0 as one of the > available partitions. > > > On a working Lite-On drive plugged into the same system with the same install > media, the equivalent logs are: > > usb 1-1.6.1: new high speed USB device using ehci_hcd and address 5 > scsi9 : usb-storage 1-1.6.1:1.0 > scsi 8:0:0:0: CD-ROM Slimtype eSAU208 2 ML05 PQ: 0 ANSI: 0 > sr0: scsi3-mmc drive: 62x/62x writer dvd-ram cd/rw xa/form2 cdda pop-up > Uniform CD-ROM driver Revision: 3.20 > sr 8:0:0:0: Attached scsi generic sg2 type 5 > scsi 9:0:0:0: Direct-Access Generic Ultra HS-COMBO 2.01 PQ: 0 ANSI: 0 > sd 9:0:0:0: Attached scsi generic sg3 type 0 > sd 9:0:0:0: [sdc] Attached SCSI removable disk > scsi 9:0:0:1: Direct-Access Generic Ultra HS-SD/MMC2 2.01 PQ: 0 ANSI: 0 > sd 9:0:0:1: Attached scsi generic sg4 type 0 > sd 9:0:0:1: [sdd] Attached SCSI removable disk > md: Waiting for all devices to be available before autodetect > md: If you don't use raid, use raid=noautodetect > md: Autodetecting RAID arrays. > md: Scanned 0 and added 0 devices. > md: autorun ... > md: ... autorun DONE. > VFS: Mounted root (iso9660 filesystem) readonly on device 11:0. > devtmpfs: mounted > Freeing unused kernel memory: 656k freed > > ===================================================================== > Transferring basename: typhoon-unit0 > Sourcing isolinux/tftpboot/cnp/x86_ng/7.0.0/targets/sb_rms/common//etc/sysconfig/pivotroot > Setting up rootfs... > > > Chris -- Matthew Dharm Maintainer, USB Mass Storage driver for Linux -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
