hi people. I just installed CentOS 5.3 on a 3.5 inch portable hard drive.
I am able to boot from that and composing this email to you.

My question is : If I use this portable OS a lot like on daily basis, would that hurt the USB port ? Will too much heat generated or some sort.

I kind of like the idea of carrying the hard drive rather than my computer to office everyday..

Thanks for sharing your thoughts..

Why would it hurt the port??

I don't see why that would be a problem. Can't be that much different than using the USB drive for data transfer. That's what the port was designed for.

Cheers

Thanks for the comments.

So it is okay to use a portable hard drive like an internal hard drive.
But I expect the speed should suffer a little bit, after all, the transfer is through a USB cable.

My this little adventure tells me that

where /dev/sda1 is my portable hard drive.

Is there a way to mount the internal hard drive ? I would like to
some data out.

Not unless you have poorly made hardware.

Just be careful how you carry the hard drive. You are far more likely to damage the hard drive my moving it frequently than you are to overheat the USB interface.

If the hard drive is not ruggedized for travel, you may lose all your data if it is dropped at the wrong time, from the wrong height, at the wrong angle.

When they are turned off, modern hard drives do a very good job of keeping the arm away from the platters. However, enough acceleration can destroy just about anything.

yeah, just mount it directly.... "mount /dev/sdb1 /mnt/internal_drive" for example. if you don't know what the drive is called, run fdisk -l

Of course. What does "fdisk -l" show?

Thanks for the reply. I know exactly what to do now (mount command is the key command following fisk -l).
(got a bit rusty since it was a long time since I last played with installation).


I have one more question:
Suppose I have two portable hard disks connected to the
computer. What is mechanism to determine which is sda (may be the internal hard drive), sdb for the first portable hard drive(but WHICH ONE, does it sorted according to the USB port ?), and
sdc is the second hard drive. Will it ever cause a problem in the Linux community ?

I could imagine I have two portable OS on two different external hard drive.


My relevant entry in to boot this portable CentOS 5.3 according to (to avoid confusion, I point out that the running OS in on the portable hard drive and is labeled as /sda1)

/sdb4/boot/menu.lst is

Note that hd1 is used with the internal hard drive as a reference point when I first boot up from the internal hard drive (hd0 is the internal hard drive when I first boot from the internal hard drive). You can see that I have not installed GRUB when I installed
CentOS 5.3 on the portable hard drive.


For complete reference, I give the outcome :

I guess sda, sdab, sdc, ... ordering might have to do with the sequence of the detection of the USB ports and right now I shall assume that the sequence on a particular computer is fixed. So there should not be any confusion.

You want to use the UUID when mounting. Using the UUID allows you to get around the problem of the disk names changing depending on how they are connected.

You can use the "blkid" command to get a list of UUID's. A typical line in fstab using a UUID to mount would look like

That's one way.

You can also use a udev (which is a very useful thing to know about) rule.
See Writing udev rules for a tuorial and some good examples.