feb 17 2009 success booting fc5copy on usb external disk thanks to Mikkel for pointing me in right direction this fc5copy was not an install, but rather a backup copy of my mainfc5 on a scsi disk on sda1 for days i was getting "cant find /dev/root.... kernel panic" finally fixed that with proper mkinitrd see below then was getting cant access resume device /dev/sda2 for days now understand that occuring bc of disk reordering part of my problem was using reisrfs on the usb, but ext3 on mainfc5 on sda1 this required an extra --preload=reiserfs in mkinitrd cmd and a further editing of the mkrootdev line in the initrd init file. root@bootp ~]# mkdir cleanrs2; cd cleanrs2 [root@bootp cleanrs2]# mkinitrd --preload=ehci-hcd --preload=usb-storage --preload=reiserfs /boot/initrd_usbrs2.img 2.6.17-1.2174_FC5 expand: [root@bootp cleanrs2]# gunzip -c initrd_usbrs2.img |cpio -i 5551 blocks [root@bootp cleanrs2]# ls bin dev etc init initrd_usbrs2.img lib proc sbin sys sysroot now modify the mkrootdev line from mkrootdev -t ext3 -o defaults,ro /dev/sda1 to mkrootdev -t reiserfs -o defaults,ro /dev/sdc1 repack: [root@bootp cleanrs2]# find . |cpio -c -o |gzip -9 >../initrd_usbrs2.img at this point, still getting "cant access resume device /dev/sda2" but no longer getting caught in "cant find /dev/root" next problem was getting caught in filesytem check on sda1,sda3 which eventually forced a reboot, but no kernel panic! The sda1,sda3 problems evidently bc of reordering of the disks (see below) I got around this gotcha by commenting out the sda1, sda3 lines in the usb fstab my mainfc5 grub.conf has following stanza for the usb boot title FC5copy (2.6.17-1.2174_FC5_usbrs2.img) /media/disk-1 (hd1,2) root (hd1,2) ## sdb3 kernel /boot/vmlinuz-2.6.17-1.2174_FC5 ro root=LABEL=rootusb rhgb quiet initrd /boot/initrd_usbrs2.img when booted up from usb: fdisk clearly shows disks have been reordered [root@bootp ~]# fdisk -l Disk /dev/sda: 250.0 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 1 30401 244196001 83 Linux <<<<was sdc1 Disk /dev/sdb: 36.7 GB, 36703934464 bytes 255 heads, 63 sectors/track, 4462 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 * 1 2676 21494938+ 83 Linux <<< was sda1,2,3 /dev/sdb2 2677 3163 3911827+ 82 Linux swap / Solaris /dev/sdb3 3164 4462 10434217+ 83 Linux so to get swap working need /dev/sdb2 instead of /dev/sda2 in usb fstab Disk /dev/sdc: 36.7 GB, 36703934464 bytes 255 heads, 63 sectors/track, 4462 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdc1 * 1 13 104391 83 Linux <<<was sdb1-7 /dev/sdc2 14 268 2048287+ 82 Linux swap / Solaris /dev/sdc3 269 281 104422+ 83 Linux /dev/sdc4 282 4462 33583882+ f W95 Ext'd (LBA) /dev/sdc5 282 1301 8193118+ 83 Linux /dev/sdc6 1302 2321 8193118+ 83 Linux /dev/sdc7 2322 4462 17197551 83 Linux [root@bootp ~]# if want mainfc5 (on sda1) mounted when boot from usb need /dev/sdb1 /fc5hold in usb fstab finally i think i have fixed the "cant find resume device" i changed the fstab swap line to use sdb2 in place of sda2 but it seemed to require rebooting twice for it to take effect at this point, my usb backup copy of my mainfc5(which is on a scsi disk) is booting without complaint The only thing i cant do is to have the fc5copy /boot found on the usb, evidently bc my bios cant see the usb disk so my fc5copy /boot was copied to sdb3 --> root (hd1,2) in grub.conf this is just a holding tank for the /boot files: I am not treating it as a "separate /boot partition", not listed in fstab regards, Jack