Hello,

 

I am wonder about can preclear work on 4TB ?

 

Sorry if this has been answered.

 

Thanks

Yes, if you have the recent version.

I am wonder about can preclear work on 4TB ?

I have pre-cleared disks up to 6TB in size without issues.  Note that if on unRAID v6 it is important that you have the latest version of the pre-clear script as earlier releases had a bug that could occur in 64-bit versions of unRAID.

 

It would be interesting to hear if any (rich ) unRAID users have yet tried pre-clear with disks larger than 6TB.

Thanks.

 

I have unraid version 5.04

will this version accept 4T drive ?

will the latest preclear work with with 5.04 ?

 

Thanks

 

 

 

Thanks.

 

I have unraid version 5.04

will this version accept 4T drive ?

will the latest preclear work with with 5.04 ?

 

Thanks

Pre-clear works the same regardless of the unRAID release.  v5 supports 4TB (and larger) drives without issue.

Yes & yes. See my sig.

Preclearing 4TB (1 run) takes about 36 hours on my system.

I just did 4 4TB drives not to long ago all at once.  Took over 80hours for 3 passes

I only preclear one pass and it takes around 33 hrs for a 4TB. My 6TB drives take 53 hrs. Upgrade to 5.06 as well. 

I've done my own form of preclear on 2 4T drives.

 

This consists of a smart long test (Which I do on every drive right away).

I suppose this is equivalent to the pre-read.

 

A 4 Pass pattern using badblocks 0xaa, 0x55, 0xff and finally 0x00.

 

Then another final smart long test

I suppose this is equivalent to the post-read.

 

I did these both at the same time via screen on unRAID 5.0.6 under ESXI 5 on an HP Microserver.

Times are below.

ModelPre-readBadblocksPost-ReadTotal

Seagate ST4000DX001 - 4TB 5400 RPM Hybrid9:0367:349:0385

Hitachi HDN724040ALE640 - 4TB 7200 RPM9:3765:569:3783

 

I've included the logs in case anyone is curious about using smartctl long test and the badblocks pattern test for burn in/clear

Seagate ST4000DX001 - 4TB 5400 RPM Hybrid

root@unRAID2:/boot/logs# date;badblocks -sv -w -c 512 -t0xaa -t0x55 -t0xff -t0x00 -o /boot/logs/ST4000DX001-1CE168_Z3014JCE.201410221000.badblocks  /dev/sdd
Wed Oct 22 10:15:47 EDT 2014
Checking for bad blocks in read-write mode
From block 0 to 3907018583
Testing with pattern 0xaa: done
Reading and comparing: done
Testing with pattern 0x55: done
Reading and comparing: done
Testing with pattern 0xff: done
Reading and comparing: done
Testing with pattern 0x00: done
Reading and comparing: 59:11:20 elapsed
86.75% done, 65:59:48 elapsed
86.75% done, 65:59:50 elapsed
done
Pass completed, 0 bad blocks found.
root@unRAID2:/boot/logs# date
Sat Oct 25 05:50:13 EDT 2014

 

Hitachi HDN724040ALE640 - 4TB 7200 RPM

root@unRAID2:/boot/logs# date;badblocks -sv -w -c 512 -o /boot/logs/HGST_HDN724040ALE640_PK2334PCGTEKJB.201410221000.badblocks -t0xaa -t0x55 -t0xff -t0x00 /dev/sdc
Wed Oct 22 10:13:56 EDT 2014
Checking for bad blocks in read-write mode
From block 0 to 3907018583
Testing with pattern 0xaa: done
Reading and comparing: done
Testing with pattern 0x55: done
Reading and comparing: done
Testing with pattern 0xff: done
Reading and comparing: done
Testing with pattern 0x00: done
Reading and comparing: 94% done, 59:13:05 elapsed
done                                
Pass completed, 0 bad blocks found.
root@unRAID2:/boot/logs# date
Sat Oct 25 04:09:51 EDT 2014

root@unRAID2:/boot/logs# smartctl -t long /dev/sdc   
smartctl 6.2 2013-07-26 r3841 [i686-linux-3.9.11p-unRAID] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org


=== START OF OFFLINE IMMEDIATE AND SELF-TEST SECTION ===
Sending command: "Execute SMART Extended self-test routine immediately in off-line mode".
Drive command "Execute SMART Extended self-test routine immediately in off-line mode" successful.
Testing has begun.
Please wait 577 minutes for test to complete.
Test will complete after Sat Oct 25 13:51:50 2014

 

 

At the end of this all,. I'll use JoeL's preclear to put the signature on the drive.

I prefer to use smartctl long test for the pre/post reads as it logs it into the drive itself.

I prefer to use badblocks as I can do multiple passes with patterns.

I'm not fond of a blind dd.  I like the ability to use patterns walking one way or another then clear with the -t0x00

However, as JoeL mentions, badblocks alone cannot determine the drive's health.

You need to look at the syslog for retries and the smart logs for changes.