I was running a pre-clear on a very large drive and accidently killed the terminal window. That was an interactive window, right? If yes, is there a way to submit a pre-clear as a batch job an view results later on with a log file or something?

 

 

A good solution might be to install the 'screen' plugin and then run the pre-clear under screen.  That way losing your interactive session does not kill the job, and you can later reconnect and go back to the screen with the pre-clear output.

 

It may be possible to run pre-clear purely as a background job, but doing so would give you no way of monitoring how it was progressing until final logs were written on completion.

Use screen, You can disconnect, Then reconnect on another session later on.

A good solution might be to install the 'screen' plugin and then run the pre-clear under screen.  That way losing your interactive session does not kill the job, and you can later reconnect and go back to the screen with the pre-clear output.

 

It may be possible to run pre-clear purely as a background job, but doing so would give you no way of monitoring how it was progressing until final logs were written on completion.

 

You can monitor preclear with unMenu.

 

You can monitor preclear with unMenu.

 

Not, however, if it's not running 

Closing the active terminal session kills the process.    Installing Screen is indeed the best option -- you can easily do that with UnMenu -- just add it from the package manager.    Then it's simple to start pre-clear;  exit; and later just go back and check on the session.

 

 

 

Thanks. I will install the screen utility after this pre-clear is done. It is a 4TB drive and only %28 done. It has been going since yesterday which means it has been running for about 15 hours now. How long does it take to pre-clear one 4TB drive? It says it is going 135MB/S.

 

This really could take 3 days.

 

 

 

 

I recently did some tests on 2 4TB Seagate drives and they took right around 39 hours to do one complete preclear.

Thanks. I will install the screen utility after this pre-clear is done. It is a 4TB drive and only %28 done. It has been going since yesterday which means it has been running for about 15 hours now. How long does it take to pre-clear one 4TB drive? It says it is going 135MB/S.

 

This really could take 3 days.

Outer cylinders on the disk will be faster than inner.  Assume 100MB/s for an average.

 

To read 1GB will take 10 seconds at 100MB/s.

That will let you read 6GB every minute. (360GB per hour)

You have 4000GB to read with a 4TB drive.

4000 / 360 = 11.1 hours

 

The pre-read will take roughly 11 hours, just to read the disk physically.  It is about as fast as it can be read. 

The writing usually takes about the same amount of time

The post-read and verification takes abuot twice as long as the read only, since the verify is checking every byte.  The verification part is CPU dependent, so a faster CPU will help.

 

11 + 11 + 22 = 44  hours (assuming a 100MB/s rate)    My estimate is pretty close, as prostaff's response shows. 

(He  averaged a bit higher than 100MB/s)

Silly question, I installed screen started my pre-clear on 4 drives, I'm going to have to close the putty window. how do i get back into it to see the progress?

Silly question, I installed screen started my pre-clear on 4 drives, I'm going to have to close the putty window. how do i get back into it to see the progress?

Installing screen is not enough. You have to manually start a screen session and then start your preclear in the screen session.

 

Assuming you have done that, then see here: Linux Screen Tutorial.

"Installing screen is not enough. You have to manually start a screen session and then start your preclear in the screen session."

 

 

I did start it and was running along pretty good but the it froze on 93% of an ssd that i will be using as cache. i was pre-clearing 4 drives 1 sdd and 3 2tb.

 

I can't telnet to it just hangs on trying to connect and the http://tower/ does not respond it just sits on waiting for response. My guess its using that cpu quite a bit i check on it  tomorrow.

 

I dont think you need to preclesr csche drive. And I am sure you shoud not pre clear ssd

 

Sent from my SGH-T889 using Tapatalk 4

 

 

If you have ssmtp installed for email support, you can use the email function for preclear.  It will send you a full report when it's done.

 

In a pinch you can also use the prefix "nohup" in front of a command so that if the window closes it will not kill the running process.

"Installing screen is not enough. You have to manually start a screen session and then start your preclear in the screen session."

 

 

I did start it and was running along pretty good but the it froze on 93% of an ssd that i will be using as cache. i was pre-clearing 4 drives 1 sdd and 3 2tb.

 

I can't telnet to it just hangs on trying to connect and the http://tower/ does not respond it just sits on waiting for response. My guess its using that cpu quite a bit i check on it  tomorrow.

 

 

Preclearing an SSD is not necessary.

Preclearing an SSD is not necessary.

 

did not know that, I will put it in my notes. thanks for all the help.

 

EDIT: well i could not get into it via the console at the pc, so i had to reboot it.  I have started all over again excluding the SSD.