Cannnot mount USB HardDrive in a certain computer

mmCC · 03-08-2007, 02:44 AM

Here is my problem: I have just installed a server with Red Hat into a Dell Poweredge 2950. Everything works fine except that for some reason that a I don't understand I can't mount an external USB Hard Drive because the system recognizes the device but not the partition (i mean, the device appears in /dev as /dev/sdg but not the partition /dev/sdg1) so I'm not able to mount it, or at least I don't know how to do it. I have tried several hard drives (three) with different filesystems (EXT2 and NTFS) but none of them works, while in other computers (with a Debian Etch and Ubuntu Dapper) they work fine. The thing that most annoys me is that when I plug a usb memory of smaller size (the size of the hard drives is between 500 GB and 1 TB) it works fine. I have some hypothesis but no idea how to prove them or how to resolve the problem:

- I have 9 filesystems mounted in the server. Is it a problem? I've readed somewhere that the kernel may have a limitation of mounted FSs. Anyway it doesn't make much sense since I get the USB memory working ...

- Maybe the problem is the size of the drives.

- I have also readed, but i can't even confirm if it's truth, that both USB and SCSI devices are handled in the same way (or even by the same driver) and that Red Hat have some limitations in the number of USB devices it can handle.

- Or, finally, is just a problem of the combination of Red Hat with the PowerEdge 2950. Is there any known limitation or problem about this?

Any help or advice will be usefull. Thanks in advance for any help.

mmCC

(in the forum, a bit less in Linux / Unix / MacOSX)

ygloo · 03-08-2007, 02:56 AM

what is the message when you try to mount USB?
repeat your mount commnad and then do:
dmesg
it shows last kernel messages, look for clues.

mmCC · 03-08-2007, 05:29 AM

Hi there,

I tried with "dmesg" and it looked like the system recognized the device correctly. These are the lines from "dmesg":

This one the devices (the one with NTFS filesystem)

Code:

usb 1-3: new high speed USB device using address 15
scsi7 : SCSI emulation for USB Mass Storage devices
  Vendor: LaCie     Model: BigDisk           Rev:     
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sdg: 1953546336 512-byte hdwr sectors (1000216 MB)
sdg: assuming drive cache: write through
Attached scsi disk sdg at scsi7, channel 0, id 0, lun 0
Info:emcp:Received add upcall for index 0x6 devno 0x800060
Attached scsi generic sg6 at scsi7, channel 0, id 0, lun 0,  type 0
USB Mass Storage device found at 15
FAT: bogus number of reserved sectors
VFS: Can't find a valid FAT filesystem on dev sdg.
usb 1-3: USB disconnect, address 15

And this is the second one (the one with EXT2 filesystem)

Code:

usb 1-3: new high speed USB device using address 16
scsi8 : SCSI emulation for USB Mass Storage devices
  Vendor: HDS72505  Model: 0KLAT80           Rev: K2AO
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sdg: 976773168 512-byte hdwr sectors (500108 MB)
sdg: assuming drive cache: write through
Attached scsi disk sdg at scsi8, channel 0, id 0, lun 0
Info:emcp:Received add upcall for index 0x6 devno 0x800060
Attached scsi generic sg6 at scsi8, channel 0, id 0, lun 0,  type 0
USB Mass Storage device found at 16
VFS: Can't find ext2 filesystem on dev sdg.
VFS: Can't find ext2 filesystem on dev sdg.
usb 1-3: USB disconnect, address 16

The problem about the error message I get when trying to mount the device is that I try to mount the device, not the partition since it's not shown in the dev folder (like mount /dev/sdg /mnt/drive instead of mount /dev/sdg1 /mnt/drive ) but I don't even know if this can be made, so the error message might not be interesting. Anyway, as far as I can remember, the message went something like this:
"mount: wrong fs type, bad option, bad superblock on /dev/sdb,
missing codepage or too many mounted filesystems
In some cases useful info is found in syslog - try
dmesg | tail or so"

The italic part is somehow reconstructed, but it definitely said something like that. Again, thanks in advance for any help.

tredegar · 03-08-2007, 03:47 PM

I had two LaCie external USB / Firewire drives.

One works perfectly but only after I had been to their website and "Upgraded the firmware" - This is a windows-only option (so I had to borrow a friend's computer to do this). The other refused to work, despite upgrades. So I unscrewed & rescued the HDD and put it in my server, where it works fine, without the LaCie trappings.

Yes, they are pretty, but no, they do not work relaiably.

I think they have had chipset problems - you could try a google for LaCie Oxford chip problem - I found a whole host of complaints, but this was maybe two years ago.

LaCie may be "Designed by Porsche" but I will not be buying another. I do not have a Porsche (car), but if this is their design philosophy, I will not be researching them further.

mmCC · 03-09-2007, 03:19 AM

Thanks for the information. I'll try that. Maybe the problem is the same in the Iomega unit. I'll see if a firmware update is required, but anyway, I'll keep on searching, since i have get the unites working in other computers. Cheers!

mmCC · 03-09-2007, 10:21 AM

Finally, I have made it work ... with help and, above it all, luck. The drive works fine if it's connected (and turned on, of course) BEFORE turning on the server. You can imagine my surprise. It doesn't make much sense for me, so I'm still looking for an answer that lets me plug and unplug the hard drives any time I want, so again, any idea or advice is welcome.

mmCC

PS: By the way, it worked with both hard drive models, Lacie and Iomega, so the hard drives finally don't seem to be the problem, ... maybe the kernel has something to do with it ...

tredegar · 03-09-2007, 03:15 PM

Experiment with your drive's different behaviour with your different distros (your profile says "Debian, Ubuntu & Red Hat").

You might also look at / google hald, udev and "writing USB rules".

You could also check the different background processes that are running when you plug the drive into the server after boot, and it's not recognised, and when you plug it in before boot, and it is recognised:
ps -A and lsmod. This may help you focus on where the problem lies.