Error Code 21 - The device is not ready from Macrium backup

dalchina · 21 Dec 2023

No. See post #4. Multiple causes.

Have you tried my suggestion?

You seem to have some kind of disk problem- so that's where you should be looking.

plaurits · 21 Dec 2023

Well before performing any action I want to check where this error is generated.
So where should I look to see this 0x15 device not ready error?

dalchina · 21 Dec 2023

How do you know which partition the error is related to?

As I suggested..

I'll make this simple.

Let's say you have partitions
a, b, c, d

Try imaging partition a ALONE.
If you get the error then, you know it's associated with partition a.

But that doesn't mean you won't get it with the others.

So now check by imaging b.
Then c.
Then d.

Repeat if the error only occurs occasionally.

Then run appropriate checks on your disk and the partitions against which you found the error occurring.

Previously suggested in 1 line...

plaurits · 21 Dec 2023

yes I know.
But that is not my question.
I know exactly when error 21 was coming from macrium full backup log.
Now I just want to see where in windows I see this error - so far I did not find it in event viewer.

dalchina · 21 Dec 2023

I can't help you. If Macrium generates that, then that's a function of that program.

Do feel free to ask on their forum.

plaurits · 21 Dec 2023

The whole reason for raising issue in this forum is that macrium support and forum say that error is just passed on from windows.
But so far they have not been able to tell me where to look for this error.

Farvatten · 21 Dec 2023

plaurits said:

But so far they have not been able to tell me where to look for this error.

I use to ritually see this same "Backup aborted! - Unable to read from disk - Error Code 21 - The device is not ready", happen about once every few months or so.

And the only thing I could associate it with was seen in the Event Viewer at the EXACT same moment that Macrium had started it's scheduled backup when it was complaining the device was not ready, and that was a System Informational Event for Ntfs ( Microsoft-Windows-Ntsf ) #98 - saying the disk had been tested and found healthy:

"Volume X: (\Device\HarddiskVolume17) is healthy. No action is needed."

Which I'm guessing is a 'chkdsk /scan' operation.

This heath check actually appears often, again only guessing it's for any disk that's never been accessed since boot time, or been disconnected and reconnected, or simply been dormant for some predetermined interval, so when it's first accessed again, Windows appears to want to check it's health.

I have not had this 'disk is not ready' message from Macrium for while, which I attribute ( rightly or wrongly ) to me forcing this heath check, if needed, by a physical access to the drive at least once before my scheduled late night backup.

I also have turned off scheduled disk maintenance ( defrag ).

Like many things with my often rocky relationship with Windows, I just do this out pure superstition now.

plaurits · 21 Dec 2023

Thanks, that was exactly the type of info I was looking for. So I will check event log again, I was searching for 0x15 in vain.

plaurits · 18 Jan 2024

Update 240118:
Even though I still do not know the root cause for this issue, it seems that rescheduling online backup to a less busy timeslot can be used as a WA. This is in line with this article from MSP360.
So in this case issue is not related to the disk, which has passed all the tests proposed.
If/when I get an update from Macrium R&D I will update this thread.