Hot Swappable internal SATA drives

[margolisd]

Hi. Newb here so go easy. I have a number of internal sata ports on my motherboard. I'd like to utilise one of these ports to use a hot swappable drive bay. The kind of bay I'm using is a CRU Dataport DX115.

So, I've set everything up. Only I can't seem to hot swap drives in the bay. The only way I can access drives in the bay is by making an entry in the /etc/fstab file and booting with the drive on.

So, is this a limitation of of the ports on the motherboard? Is there any way I can make the port hot swappable?

If not, I can live with this, but I have another problem. When I boot with a drive in the bay, it is always assigned the device name sdb1. This bumps my RAID5 to sdc. Is there a way I can edit the fstab file so that the RAID is always SDB. That way SDC can be reserved for the removable drive that may or may not be there.

Hope that makes sense. Any ideas appreciated.

[Rubberman]

First, don't use device id's as in /etc/fstab. Label the drives/partitions instead and mount using the label instead. The system is free to change the ID's whenever you reboot if it wants to (scan order has changed for instance). Using labels means that even if what was /dev/sdx is now /dev/sdy, it will still mount normally using the label.

Second, if you have an entry in /etc/fstab, normally it has to be available when you boot the system. However, you can change that by using the 'noauto' option which will allow you to manually mount the drive. Here is a sample of how the entry might be in /etc/fstab:

LABEL=xyzzy /mnt/xyzzy ext3 noauto 0 0

This tells the system to mount the drive/partition labeled 'xyzzy' on /mnt/xyzzy, that it is an ext3 file system, don't auto-mount the drive at boot time, the drive doesn't need to be dumped, and the system should not check if it needs to run fsck on it when mounted.

Finally, if you are going to swap the drive out, you still have to unmount it first. I assume you will be running as a sudoer so you don't need to be root to mount/umount the drive.

[margolisd]

Perfect! That works great!

Thanks for your time

[Rubberman]

Perfect! That works great!

Thanks for your time

My pleasure! One thing to do, before you umount the drive, is to issue the 'sync' command to ensure that all cached updates have been written to disc. I know that umount is supposed to do that, but I have found that it doesn't at times. It's probably a bug, but I don't know for sure and I always keep in mind our friend Murphy's Law.