Shrink array using the script. How long does it take to zero out a drive?

[ProphetSe7en]

I am using the method to shrink array and keep parity valid. The drive I am zeroing out is only 4 TB, so I thought it would be finished in 12-14 hours or so.

 

But now, 32 hours later it is still running.

 

So I am wondering how long this process usually takes. 

[JonathanM]

The last time I tried it (years ago) I gave up after a week.

 

There are very few scenarios where that method makes the most sense, normally it's better to just rebuild parity and get back protected sooner rather than waiting.

 

What is your situation? Are all your drives proven healthy? Zero errors on all recent parity checks?

[ProphetSe7en]

No issues. Replaced parity a few days ago and everything is ok. Only reason I wanted to use this method was to keep parity. Emulating a drive and rebuilding it with a new 18TB drive would probably take around 40 hours or so. So I figured that zeroing out a 4 TB drive would be much faster.  Apparently its not! 

 

I saw spaceinvaderone`s  video on shrinking array. For his 1 TB drive it tok 3-4 hours, so why should a 4 TB drive take  over 10 times that?

 

 

[itimpi]

3 hours ago, ProphetSe7en said:

So I figured that zeroing out a 4 TB drive would be much faster.  Apparently its not! 

It sounds as if something is slowing down the zeroing process?  I would normally think it should run at a similar speed to a parity check (i.e. around 2 hours per TB) if the array is not simultaneously active with other array activity.   You are likely to get better informed feedback if you attach your system’s diagnostics zip file to your next post in this thread so we can see if anything obvious can be seen.

[ProphetSe7en]

I hated the wait and the lack of any progressbar during the script. So I decided to create a new config and just remove the drive, then let parity rebuild. Still take a lot of time, but at least now I know how long it takes.