How to determine which usb drive is faulty

[zimon]

Hi,

I have a boot mirror with 3 identical usb drives. One drive showed up with 22 write errors so I would like to replace it before it gets worse.
But how can I tell which physical usb drive is the one with the 22 errors? Can I just unplug one and then easily add it to the pool again?

Hopefully there is a way with 0 risk.

 

[dlavigne]

Yes. Though rebuilding a mirror on USB drives will be hard on all of them. Mirrored boot devices are really meant for SSDs.

 

[zimon]

so there is no way? Why is it tough to rebuild a mirror on USB drives?
What would be the best practise here? I thought using a usb drive as a boot volume is best practise since it does not cost much and it does not occupy a SATA slot.

 

[dlavigne]

USB sticks are cheap and easy to replace when they inevitably (and fairly quickly) die. There's no advantage to mirroring them. If you're going to use USB sticks for the boot device, ensure you always have a saved copy of your latest config and a few spare sticks laying around. When one stick dies, your downtime is the time it takes to reinstall to a new stick and restore your config.

 

[zimon]

yes I have the latest config saved but I never restored my system from it and tbh I am a bit scared to do so.
On the other hand replacing a failed usb drive which is mirrored takes 2 seconds. ( and I can't do much wrong)