Mr.Jason wrote:
> I'm curious. Lets say you have two HD's on your linux box. The secondary you
> use much as a backup medium. Then you want to replace the secondary drive
> while computer is on.
> If you spin down a hard disk is it OK to remove it and replace while power
> is on? I suppose not, but please speculate and analyze the events of hotswap
> ordinary IDE disk. Would it make difference if the disk is on mobilerack or
> not?

We actually do something similar. We have a backup HDD that is always
connected to IDE cable, but we only power it up while the backup is running.
We use a small electric device, which we control via serial port (RS232). So,
before backup is run, we power up the HDD, mount it, and run the backup. When
it completes, we unmount, hdparm to stop it, and just cut the power. It's beed
working flawlessly for years now. We never disconnected the IDE cable though.

You may wonder why we do this. It is some kind of protection against hackers.
If someone even manages to get in and get control of computer, there is really
small chance that he will notice our backup trick, and he won't see the backup
disk at all. Well, I do actually do this, but a colleague of mine who is
sysadmin for our webserver.

--
Milan