Seagate 8TB archive drives - Pre clear question

[ashman70]

I just pre cleared a 4TB drive and it took just a tad over 53 hrs for one pass, how long is it taking you to do one pre clear pass on an 8TB drive? Am I looking at over 100hrs if a 4TB took 53?

[trurl]

Never done 8TB but my last preclear of a 6TB took about 43 hours. Are you using the faster post-read option?

[danioj]

I just pre cleared a 4TB drive and it took just a tad over 53 hrs for one pass, how long is it taking you to do one pre clear pass on an 8TB drive? Am I looking at over 100hrs if a 4TB took 53?

 

Hi. I did extensive testing with the Seagate 8TB SMR drives. I posted results here: https://lime-technology.com/forum/index.php?topic=39526.msg386233#msg386233

 

In short, 3 passes (using Bjp's faster script) is 133 Hours and 19 Minutes

 

== invoked as: ./preclear_bjp.sh -f -A -c 3 /dev/sde
== ST8000AS0002-1NA17Z   Z8404KRE
== Disk /dev/sde has been successfully precleared
== with a starting sector of 1 
== Ran 3 cycles
==
== Using :Read block size = 1000448 Bytes
== Last Cycle's Pre Read Time  : 19:42:48 (112 MB/s)
== Last Cycle's Zeroing time   : 17:07:40 (129 MB/s)
== Last Cycle's Post Read Time : 20:59:15 (105 MB/s)
== Last Cycle's Total Time     : 38:07:58
==
== Total Elapsed Time 133:19:52

[ashman70]

Trurl, how would I find out?

[danioj]

Trurl, how would I find out?

 

If you're using the faster script as I mention above - using the -f switch.

 

See how I executed mine in the above code snippet.

 

https://lime-technology.com/forum/index.php?topic=32564.0

[gfjardim]

If you're using the Preclear Plugin, it would appear this way:

 

[ashman70]

What happens to the existing pre clear plugin I have? Does it get upgraded ?

[danioj]

What happens to the existing pre clear plugin I have? Does it get upgraded ?

 

No change to the plugin. The plugin switch as shown above (AFAIK) only appears (or it used to) when the preclear script you have installed supports a faster post read (e.g. the Bjp script I linked to above).

 

To switch between the two you just have to do is replace the original preclear script on the flash drive with the newer one (but renamed to be equivalent to the original). You don't need to change or upgrade the plugin.

[ashman70]

So I can't execute the faster version from the gui? It has to be executed from the command line? I am confused.

[danioj]

So I can't execute the faster version from the gui? It has to be executed from the command line? I am confused.

 

OK - just do this:

 

1) Download the fast preclear script from the link I posted above

2) Rename it to the same name as the normal preclear script

3) Replace the normal preclear script that the plugin uses with the faster one you have just renamed

4) Execute the plugin from the GUI

- The option to do the faster post read will now be selectable

5) Select the faster post read option now available (along with whatever other parameters you want to select)

6) Execute

 

Hope this helps.

[ashman70]

Thanks, followed your instructions to the letter, still get the old pre clear option without the faster pre clear option. I think I might need to reboot, will do this tomorrow.

 

Thanks.

[trurl]

Thanks, followed your instructions to the letter, still get the old pre clear option without the faster pre clear option. I think I might need to reboot, will do this tomorrow.

 

Thanks.

Rebooting cannot possibly have any affect on this. From command line, post results of

ls -lah /boot/config/plugins/preclear.disk

[ashman70]

drwxrwxrwx  2 root root 4.0K Dec  3 21:14 ./

drwxrwxrwx 21 root root 4.0K Mar  1 23:32 ../

-rwxrwxrwx  1 root root 228K Oct  9  2013 libevent-2.0.21-x86_64-1.txz*

-rwxrwxrwx  1 root root 1.2M May  7  2013 ncurses-5.9-x86_64-2.txz*

-rwxrwxrwx  1 root root  63 Dec  3 21:08 preclear.disk-2015.11.18.md5*

-rwxrwxrwx  1 root root 122K Dec  3 21:08 preclear.disk-2015.11.18.txz*

-rwxrwxrwx  1 root root  84K Apr  5  2014 preclear_disk.sh*

-rwxrwxrwx  1 root root 200K Oct  9  2013 tmux-1.8-x86_64-1.txz*

[trurl]

drwxrwxrwx  2 root root 4.0K Dec  3 21:14 ./

drwxrwxrwx 21 root root 4.0K Mar  1 23:32 ../

-rwxrwxrwx  1 root root 228K Oct  9  2013 libevent-2.0.21-x86_64-1.txz*

-rwxrwxrwx  1 root root 1.2M May  7  2013 ncurses-5.9-x86_64-2.txz*

-rwxrwxrwx  1 root root  63 Dec  3 21:08 preclear.disk-2015.11.18.md5*

-rwxrwxrwx  1 root root 122K Dec  3 21:08 preclear.disk-2015.11.18.txz*

-rwxrwxrwx  1 root root  84K Apr  5  2014 preclear_disk.sh*

-rwxrwxrwx  1 root root 200K Oct  9  2013 tmux-1.8-x86_64-1.txz*

This is the original preclear script, not the faster one.

[ashman70]

I found it, thanks for your help and patience.

[isvein]

I got the 5TB archive disk, as it is big enoguh for me.

But this preclean will take some time.....

Preclear in progress... Zeroing (1 of 3). 96% @ 41 MB/s (32:33:21)

[skylark]

I've just cleared an 8TB Seagate drive using the plugin without faster post read (i'm old school and really want ALL of the disk to be fully exercised) ... took 76hrs. Got one more to go. Guess i could try that faster preclear switch if it appears.

 

[JorgeB]

I got the 5TB archive disk, as it is big enoguh for me.

But this preclean will take some time.....

Preclear in progress... Zeroing (1 of 3). 96% @ 41 MB/s (32:33:21)

 

This is slower than normal, unless you're using a USB enclosure.

[isvein]

I got the 5TB archive disk, as it is big enoguh for me.

But this preclean will take some time.....

Preclear in progress... Zeroing (1 of 3). 96% @ 41 MB/s (32:33:21)

 

This is slower than normal, unless you're using a USB enclosure.

 

connected internal, but using an old 1556 system, may be why.

[JorgeB]

connected internal, but using an old 1556 system, may be why.

 

Still doesn’t explain the slow speed unless you’re using a slower add-on controller, see here for normal preclear time using the same disk.