Reintroduce a block device to Linux without reattaching it manually

[Beckett]

Greetings, everyone. I have a question which may not seem very practical but nevertheless piqued my curiousity - is there a way to reintroduce a block device (e.g. an external HDD) to Linux kernel without reattaching it manually? What I mean is not just umount and mount it again but rather go deeper - make the kernel "think" that the device is detached from the system and is attached again. Thanks in advance.

[Rubberman]

Is there any particular reason why you want to do this? So, you want it to release the /dev/name such as /dev/sdn, and then reassign it at your command?

[Beckett]

Thank you for reply, Rubberman.

Is there any particular reason why you want to do this?

It's a mere curiosity. Also, I'd like to understand better how the kernel discovers new hardware and configures it.

So, you want it to release the /dev/name such as /dev/sdn, and then reassign it at your command?

Well, sort of. Since I'm not familiar very well with Linux kernel's way of doing this work, I can't say if your words are exact paraphrase of my question. Simply put, I'm interested in "simulating" disconnection of a hardware using shell command or system call so it would appear to the OS as I physically reattached the device. Besides, it'd be convenient to make the kernel rediscover and automatically remount my external HDD without having to reattach it manually. I know that I can just remount it, but I'm looking for another way. In other words, I want more control over this process. It's always good to have more than 1 option.

[Rubberman]

You might want to look at these resources for more information about this subject:

1. Chapter*8.*Dynamic Kernel Device Management with udev
2. http://www.kernel.org/doc/ols/2002/o...es-368-375.pdf

FWIW, two sites that are very useful for learning about low-level Linux cruft are these:

www.kernel.org
www.tldp.org

[Beckett]

Much appreciated, Rubberman.