I did a clean install of F11 x86_64 on a system that also has F10 i686, F8, and others for a multi-boot situation. F11 is working fairly well except for one problem. I can't mount one of my disks. I have nine disks connected to the system. Most of them have a single partition (i.d. sda1, sdb2, sdc1, etc) and they work fine. The disks are a mixture of SATA and PATA. However there's a problem with one SATA disk. Here's what happens: The kernel boots up and all the disks are recognized correctly to start with: # dmesg | egrep '2:0:0|sdb' scsi 2:0:0:0: Direct-Access ATA WDC WD10EACS-00Z 01.0 PQ: 0 ANSI: 5 sd 2:0:0:0: [sdb] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) sd 2:0:0:0: [sdb] Write Protect is off sd 2:0:0:0: [sdb] Mode Sense: 00 3a 00 00 sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 2:0:0:0: [sdb] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) sd 2:0:0:0: [sdb] Write Protect is off sd 2:0:0:0: [sdb] Mode Sense: 00 3a 00 00 sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sdb: sdb1 However, there is no /dev/sdb1, and no apropriate label for sdb1 in /dev/disks/by-label. Yet it's there: # fdisk -l /dev/sdb Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x000d6b69 Device Boot Start End Blocks Id System /dev/sdb1 * 1 121601 976760032 83 Linux I can do this: # hdparm -z /dev/sdb and sdb1 appears in /dev. But when I try this: # mount /dev/sdb1 /mnt_loc mount: /dev/sdb1 already mounted or /mnt_loc busy and this: # fsck /dev/sdb1 fsck 1.41.4 (27-Jan-2009) e2fsck 1.41.4 (27-Jan-2009) fsck.ext3: Device or resource busy while trying to open /dev/sdb1 Filesystem mounted or opened exclusively by another program? All the other disks on the system worked fine. All the disks work fine with F10. The disk in question and most of the other disks were partitioned and new filesystems created with identical commands on F10. One of the other disks (which wasn't being used) was identical in size to the problem disk, although it was a different brand and model. I dd'ed the problem disk to this other disk and rebooted. Now I have the exact same problem on that disk as well. I have no idea what is trying to use these disks. I booted the F10 system and ran fsck on them. They still worked fine on F10, but the same problem on F11. Since the problem has followed the "data" from one disk to another, I don't think it's a hardware problem. Also smartctl shows no problem. I also tried booting in single user mode and still had the problem. Does anybody have any ideas what might be causing this and how to fix it? Thanks Rich