Originally Posted by MTK358
In Arch, I very often get errors about HAL when mounting a drive using a GUI file manager, especially after updates.
I wonder what HAL really does, how to fix it, or is there a better alternative?
HAL stands for "hardware abstraction layer", it aims to be sitting in between your software and your hardware, and it manages things like disks, audio cards, optical drives, usb gadgets or whatever you wish.
If you have a problem with HAL at a given point, open a thread and be specific about the symptoms, errors, messages, etc. Maybe we can help you.
As for your question, there's no 1:1 alternative for HAL. You can't just replace HAL with anything else and continue working just like yesterday. Most software is migrating to many components (udev, upower, policykit and devicekit, and a few others) which do the work that HAL did, but as I said, the software needs to be migrated for this to work.
Being that said, most up to date distros should not depend much on HAL any longer for most stuff. So, this depends to a large degree on your distros and desktop environment. In my Gentoo box, as an example, the only packages still depending on HAL are phonon (which is mostly used for desktop notifications in kde) and k3b (the kde burning tool).
Remember that if you have software that depends on HAL you must make sure that the hald services is being started when you boot your system. Otherwise they will not operate correctly, if at all.