Mirrored USB boot keys

[ben42153251]

This would be a very simple feature to implement,

 

Allow mirroring of two USB UNRAID boot keys, this way if one fails there is an exact copy on the other that can simply be booted and the failed USB key rebuilt later from the web interface.

 

Simple MDADM raid I think would suffice, I intend to run UNRAID unattended, the motherboard has remote management interface including even viewing the BIOS over remote. Problem is I can't fix a failed USB key, but I could just boot a mirrored one.

 

.......... Actually, you know what would be even better than this?

 

An option in the web interface to "backup" to a spare USB key, that just uses DD to copy the entire disk to the backup usb key.

 

That way when we are happy with installations it's possible to take a backup of the boot system.

[abs0lut.zer0]

This would be a very simple feature to implement,

 

Allow mirroring of two USB UNRAID boot keys, this way if one fails there is an exact copy on the other that can simply be booted and the failed USB key rebuilt later from the web interface.

 

Simple MDADM raid I think would suffice, I intend to run UNRAID unattended, the motherboard has remote management interface including even viewing the BIOS over remote. Problem is I can't fix a failed USB key, but I could just boot a mirrored one.

 

.......... Actually, you know what would be even better than this?

 

An option in the web interface to "backup" to a spare USB key, that just uses DD to copy the entire disk to the backup usb key.

 

That way when we are happy with installations it's possible to take a backup of the boot system.

 

IF it was doable..

then you would first need 2 licenses as the GUID of the USB's would be different

[Helmonder]

Correct... However it really would be nice if the license structure would not be based on the usb flashdrive.. Failure of a flashdrive (which is now by design a single point of failure) now makes the array go kaput.. New keys are given quickly, but still..

 

[gundamguy]

Correct... However it really would be nice if the license structure would not be based on the usb flashdrive.. Failure of a flashdrive (which is now by design a single point of failure) now makes the array go kaput.. New keys are given quickly, but still..

 

I'm not sure there is a better way honestly. What would you tie the license to if not the GUID of the flash?

 

There are some SD-card readers out there that have GUID's that work with unRAID, meaning you can register the reader and be able to switch the cards out...

 

Note: Most do not work with unRAID because the reader doesn't have a unique GUID... but there are the rare few that do have that...

[Helmonder]

I agree..

[Fischje]

I must agree.

 

I think there must be feature to register two GUIDs. At a user-interface u had to choose the active one. Through this a administrator could easily switch to the backup stick if needed. At midnight, on sunday or at any time....

 

 

[SSD]

Flashdrive failures have been exceedingly rare. The few I remember have been due to using low quality, non-brand devices, like the kind you'd get at a tradeshow.

 

The risk of data loss in the event of a flash failure is also very low.

 

Using a flash backup can be dangerous. Since the flash tracks drives assignments, using a backup when drive assignments were different can be disastrous. Imagine your parity drive were upsized, and the old parity made into a data disk. Using a flash backup might put that disk back into the parity slot, and start destroying the data on the old parity disk as the array is brought online.

 

If a flashdisk were to fail, rebuilding it is not complex or dangerous. Only a tiny bit of know how is required.

 

For these reasons I discourage boot disk backups.

 

Implementing some sort of automated backup might well be doable, and may overcome my concerns to a degree. But if the flash failed I am not sure I would trust the backup which might have been in the middle of syncing one of the critical files, which might now be empty, incomplete or corrupt. I'd likely rebuild the flash anyway.

 

So buy a good quality flashdrive and rest easy that if it fails, recovery is easy to do. Read up on the recovery process if you're worried. Backup your data, not your flash.

[gundamguy]

Using a flash backup can be dangerous. Since the flash tracks drives assignments, using a backup when drive assignments were different can be disastrous. Imagine your parity drive were upsized, and the old parity made into a data disk. Using a flash backup might put that disk back into the parity slot, and start destroying the data on the old parity disk as the array is brought online.

 

I've seen plenty of examples of this in the general support forums. It's a real shame too, because the users think what they are doing is wise (backing up data is what we are trained to do) but then the super data that knows disk locations assigns the wrong disk as parity and boom, major data loss.

 

I've been meaning to create a script that "backs up" only the parts of the flash that can't get you into trouble, skipping the files that cause these problems, but I've been tired and busy and honestly don't think it adds that much value.

[ljm42]

Seems like an easy fix would be to have the array refuse to start if the assigned parity drive has a valid filesystem.

[jonp]

Seems like an easy fix would be to have the array refuse to start if the assigned parity drive has a valid filesystem.

 

Except when there are only two disks in the system, parity will be an exact mirror of data disk.

[ljm42]

Seems like an easy fix would be to have the array refuse to start if the assigned parity drive has a valid filesystem.

 

Except when there are only two disks in the system, parity will be an exact mirror of data disk.

OK, but that should be an easy configuration to detect, right?

[jevans04]

Seems like an easy fix would be to have the array refuse to start if the assigned parity drive has a valid filesystem.

 

Except when there are only two disks in the system, parity will be an exact mirror of data disk.

 

How about a warning message before the array starts that says "WARNING!!!  Assigned Parity Drive has a valid file system.  Are you sure you want to proceed?  Doing so will erase all files currently on this disk." and requires the user to select yes or no?

[kizer]

Honestly and I do mean honestly. The best solution for this no matter what is to take a screen shot of your Assigned drives and set your array to not start when it boots. Make it a HUGE habit to check your assigned drives against your screen shot before you start. I normally just focus on the last 4 of every drives serial number for a quick check. Plus I only have 8 Drives + Cache so its pretty quick. I do this every time I boot my Array. I've been paranoid since V4+ Something and its not done me wrong, but I always do this just in case.

 

I always use the same machine to Admin my server so I just keep a screen shot on my desktop. When I make any major changes I take another screen shot and delete the old.

 

I do have a copy of my Flash Drive on my Windows machine too, but when I make Drive changes I copy a new Backup of my Flash drive.

I do not think an Automated backup is a wise idea unless you have a strict workflow when it comes to making changes and booting your server.