USB external Hard Disk Drive & Linux

[stockhausen]

Has anyone ever had any experience of connecting a USB (or Firewire) external Hard Disk Drive device to a Linux system?

I want to do this with a 320GB LaCie d2 QUADRA device for backup purposes - SuSE Linux 10.2. Reading the manual on the LaCie web-site, I get the impression that it can only be used with Windows and Mac OS 10 - presumably because it is formatted as NTFS (which is not normally supported by Linux).

I suspect that if one were to reformat it as ext3, ReiserFS or whatever, it should work. However, I would like to know before I shell out for one.

Any feedback much appreciated.

 

[stockhausen]

I have used a Western Digital Passport(USB) drive formatted with Fat32 partitions with Gentoo and had no problems. Depending on your distro it should either auto detect and mount the drive or you will have to do it manually. The manual approach isn't difficult.

Thanks for your reply, it is good to know that it is possible.

Presumably your WD Passport (USB) drive was no more that 127Gb? Since I am looking to backup data files and using a 320Gb drive, I will have to format it as ext3, ReiserFS or something. I am not bothered about accessing it from Windows.

 

[stockhausen]

I know my uncle (a linux dev) has LaCie drives, and even had one that came pre installed with a linux os that he could boot from (mandriva) or similar...
they've been around for ages, and say they're linux comp on the box (I've just checked)

I have now actually got hold of a 320GB LaCie d2 QUADRA and it definitely doesn't mention Linux anywhere on the box for that. I have logged a tech support ticket with LaCie.

It's quite a cool unit actually, offers eSATA, USB2, Firewire 400 & 800 connection options - decisions, decisions - why can't I have Ethernet as well

the Mint linux i was playing around with read my external usb hdd. It was formatted in HFS+ which allows files >4gb. If you get Macdrive then windows can read this too.

Good point about files > 4Gb, I hadn't thought of that.


I can see this device in Windows & Linux:
o Windows - under Computer Management, it is shown as Disk 1 - Unknown - 298.09Gb. Not yet shown as a USB device
o RedHat Fedora Core 2 - shown as LaCie 298.0Gb - /dev/sda6
o SuSE Linux 10.2 - shown as LaCie hfsplus 298.09Gb - /dev/sda6

I am pretty confident that if I partition and format it (probably as reiserfs) under Linux it will work. On reflection and based on this site, I will use ext3.


As an experiment, I reformatted a 128Mb USB DISGO Thumb drive from FAT to reiserfs to work under SuSE Linux and used it without problem. Strangely enough, when I reformatted it as NTFS, FAT32 & FAT to work under Windows, it seemed to have lost some space (about 5Mb) - I haven't explained or resolved this yet although it may have something to do with space reserved for the journal?


EDITED: I have had a response from LaCie that reads:

Thank you for contacting LaCie Technical Support. The biggest disk's work with linux as long as you have support for firewire and USB hard drives. Which I'm sure you do. The 320GB just needs to be formatted which ever way you want. Just format it like you would an internal hard drive on Linux.

I can't quite see why they shouldn't include this on their web-site, in their documentation and on the packaging?

 

[stockhausen]

I sent the following query to LaCie:

Since the LaCie disks seem to work with Linux, is there any particular reason that you seem to make absolutely no mention of Linux on your web-site, in any documentation or on any packaging?

They replied as follows:

Because there is no support for Linux on many of our products. If we supported them we would let you know what you needed and how to get the drive to work. There is not much that is special about Linux to get external drives to work, but we would have to do a lot of changes to say we support Linux.

What a sad state of affairs

 

[stockhausen]

I have now tried 'ext3' and FAT32, both of which seem to work fine. I will probably stick with ext3.

 

[stockhausen]

In order to try and achieve some sort of compatibility, I decided to go for FAT32 because I was under the impression that a FAT32 partition could be up to 2Tb Link 1.

In point of fact, under Windows 2000, you can't create a FAT32 partition larger than 32Gb:

Maximum volume size = 32 GB (This is due to the Windows 2000 format utility. The maximum volume size that Windows 98 can create is 127.53 GB) Link 2

When I tried to create a 33Gb partition under W2K I got an error MsgBox reading "Volume size is too big"

So, it's back to Windows '98 SE then

 

[stockhausen]

I am having MAJOR problems using an external USB disk as a backup device with SuSE 10.2. Basically, USB seems to be incredibly slow.

On a 320GB LaCie external hard disk drive, I formatted two partitions, each of about 10GB - one as ext3 and the other as FAT32.

Copying 20 files totalling just over 4,027 million bytes (3.75GB) took 4 minutes 9 seconds to the FAT32 partition under Windows 2000 and 42 minutes 7 seconds to the ext3 partition under SuSE 10.2.

Can anyone offer any suggestions as to why data transfer to an external disk is so much slower under SuSE 10.2 than under Windows 2000 and whether I can do anything about it?

 

[stockhausen]

what does hdparm -tT /dev/scd0 (or whatever your device is, use mount to find out)

what does hdparm -i /dev/scd0 say?

The drive is currently connected through a Firewire 400 port rather than USB, FW400 seems to be about twice as fast as USB under SuSE 10.2 but still 5 times slower than Windows 2000. It is identified as /dev/sda1 and mounted as /media/disk.

hdparm -tT /dev/sda1 gives:
Timing cached reads: 1976 MB in 2.0 seconds = 987.54 MB/sec
Timing buffered disk reads: 70 MB in 3.08 seconds = 21.41 MB/sec

Reverting to USB gives pretty similar (read)figures:
a) Timing cached reads: 1952 MB in 2.0 seconds = 975.46 MB/sec
b) Timing cached reads: 1966 MB in 2.0 seconds = 982.44 MB/sec
c) Timing cached reads: 1982 MB in 2.0 seconds = 940.39 MB/sec
a) Timing buffered disk reads: 72 MB in 3.07 seconds = 23.44 MB/sec
b) Timing buffered disk reads: 72 MB in 3.05 seconds = 23.60 MB/sec
c) Timing buffered disk reads: 72 MB in 3.02 seconds = 23.81 MB/sec


hdparm -i /dev/sda1 gives HDIO_GET_IDENTITY failed: Invalid argument

N.B. this is not an IDE drive, it is a SATA drive currently connected via Firewire
Also, I am interested in Write speeds, not Read speeds.

I rather wonder whether using ext3 may be causing the problem, would I be better off using ext2?

Many years ago, on a Compaq ProLiant 4000, I used to use a piece of software which I believe was called cpqmon386 - I think it was based on something else but can't remember what. It used to display handy performance and utilisation stats. Do you have any idea whether there is anything equivalent under Linus? Incidentally, I don't mean 'top' which doesn't provide data on Disk I/O.

 

[stockhausen]

I have now loaded Fedora 7 and the time taken to copy files to the external USB drive are as I would expect them to be (very much faster than SuSE 10.2), so I guess that it must be a problem with SuSE.