New install of Ubuntu 11.04 - External Harddrive not mounting

is the bios detecting the drive? if sudo fdisk -l is not showing the drive, i guess the pc/bios is not seeing the drive.

if it is an external drive (2,5#) are both usb-cables connected? or only one? sometimes there is not enough power when using 1 cable, so the harddrive will not start correctly and because of that, the system doesnt see the drive

Thanks Michael. There has never been an issue with the BIOS detcting the Ext HD on this machine before. ANd as I mentioned, when I ran Ubuntu from my flash drive the drive showed up fine. It was only after installing Ubuntu permanently that the Ext HD disappeared. So I don't think it is BIOS related. It is a mains powered drive with a single USB.

can you paste the output of "dmesg | tail -n 30" after plugging in the drive please? maybe wait 5-10 seconds after pluggin it in and then run the dmesg-command

jeremy@jeremy-EQUIUM-A210:~$ dmesg | tail -n 30
[ 14.061984] [drm] fb depth is 24
[ 14.061986] [drm] pitch is 5120
[ 14.062259] Console: switching to colour frame buffer device 160x50
[ 14.062298] fb0: radeondrmfb frame buffer device
[ 14.062300] drm: registered panic notifier
[ 14.062310] [drm] Initialized radeon 2.8.0 20080528 for 0000:01:05.0 on minor 0
[ 14.083480] input: ov519 as /devices/pci0000:00/0000:00:13.0/usb2/2-1/2-1.1/input/input7
[ 14.083733] gspca: video0 created
[ 14.084603] usbcore: registered new interface driver ov519
[ 14.175857] ppdev: user-space parallel port driver
[ 15.322612] EXT4-fs (sdb1): re-mounted. Opts: errors=remount-ro,commit=0
[ 16.562170] usb 1-4: usbfs: interface 0 claimed by usblp while 'usb' sets config #1
[ 17.638703] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 19.529831] EXT4-fs (sdb1): re-mounted. Opts: errors=remount-ro,commit=0
[ 110.453546] wlan0: authenticate with 00:8b:5d:8c:9c:9a (try 1)
[ 110.456075] wlan0: authenticated
[ 110.593306] wlan0: associate with 00:8b:5d:8c:9c:9a (try 1)
[ 110.596319] wlan0: RX AssocResp from 00:8b:5d:8c:9c:9a (capab=0x431 status=0 aid=3)
[ 110.596329] wlan0: associated
[ 110.603432] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 111.372099] Intel AES-NI instructions are not detected.
[ 111.634422] padlock_aes: VIA PadLock not detected.
[ 120.656028] wlan0: no IPv6 routers present
[ 539.803156] exe (2496): /proc/2496/oom_adj is deprecated, please use /proc/2496/oom_score_adj instead.
[ 1562.514795] cdrom: This disc doesn't have any tracks I recognize!
[ 2882.992209] CE: hpet increased min_delta_ns to 20113 nsec
[ 4653.287390] usb 1-2: USB disconnect, address 3
[ 4660.320062] usb 1-2: new high speed USB device using ehci_hcd and address 6
[ 5041.228261] process `skype' is using obsolete setsockopt SO_BSDCOMPAT
[ 8651.800249] usb 1-2: USB disconnect, address 6

I suggest you plug the device into a windows system and chkdsk it. When you remove it remember to use the safetly remove hardware feature. This is ESPECIALLY critical with FAT based filesystems as they have very little robustness. If you have been simply removing the device without using the correct procedure then this would explain why you are getting issues.

Could you run command "sudo blkid" and post file "/etc/fstab".

@actionparsnip: Thanks for the suggestion. Unfortunately no joy.

@delance:

From sudo blkid

/dev/sda1: UUID="033b0cf9-3af1-47b5-aa01-3ed77dec6384" TYPE="ext4"
/dev/sda5: UUID="0f1f8e06-1491-45e1-871a-31b42c1bb493" TYPE="swap"
/dev/sdb1: LABEL="LACIE" UUID="CAD4EC63D4EC52ED" TYPE="ntfs"

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
/dev/sdb1 / ext4 errors=remount-ro 0 1
# swap was on /dev/sdb5 during installation
UUID=0f1f8e06-1491-45e1-871a-31b42c1bb493 none swap sw 0 0

Thanks again for the assistance.

I don't understand. fstab is mounting root file system on sdb1, which is NTFS one. So you should not be able to boot.
The installation of bootloader is not clean, and you could fix this by reinstalling Grub2 ( https://help.ubuntu.com/community/Grub2#Reinstalling%20from%20LiveC) but it will not fix your issue.

So... I ran Boot-Repair and now the LaCie drive is showing up on the desk top and in the launcher. Result! Thanks.

However, this seems to be at the sacrifice of my thumbdrive which is no longer being recognised ... Strange.

The connection between the LaCie drive and Ubuntu is dreadful. It doesn't hold up and loses the the link when attempting to copy between the external drive and the laptop. Something definitely not right.

I run my laptop during the night and usually at morning, the LaCie external drive is disconnected. So it seems there is some issue with such disk.

The LaCie drive connects fine to other machines on Windows OS - It appears that ubuntu doesn't like having 2 USB external drives (flash and disk) connected at the same time. I have decided to leave Ubuntu behind. Too many problems with this, and file/printer sharing, syncing MP3 player. It's a shame as I like many of the features of the OS. Thanks for your help.