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[SOLVED] Preclear and WD EARS with jumper

Featured Replies

Hello all,

 

I just recently purchased and installed a new jumpered WD 2TB EARS drive in my unRAID server, to go with two other jumpered WD 2TB EARS drives that I already had in my server.  I just ran the preclear, but I did it with the "-a" option.  It started at sector 64, but I think I needed to start at 63.  Did I do the right thing or should I go back and rerun the preclear with a different option or no option?

 

Thanks in advance for your assistance!

 

Mod edit: Marked thread [sOLVED].

- Raj

Hello all,

 

I just recently purchased and installed a new jumpered WD 2TB EARS drive in my unRAID server, to go with two other jumpered WD 2TB EARS drives that I already had in my server.  I just ran the preclear, but I did it with the "-a" option.  It started at sector 64, but I think I needed to start at 63.  Did I do the right thing or should I go back and rerun the preclear with a different option or no option?

 

Thanks in advance for your assistance!

if you user -a, you would have specified sector 63.  if -A, sector 64.

 

If jumpered you want sector 63.

 

you can use

preclear_disk.sh -t /dev/sdX

to see if (and how) they are set.

 

If they are precleared, you can use

preclear_disk.sh -C 64 /dev/sdX

or

preclear_disk.sh -C 63 /dev/sdX

to convert from one to the other.. (as long as you did not yet assign them to the array just yet)

  • Author

if you user -a, you would have specified sector 63.   if -A, sector 64.

 

If jumpered you want sector 63.

 

you can use

preclear_disk.sh -t /dev/sdX

to see if (and how) they are set.

 

If they are precleared, you can use

preclear_disk.sh -C 64 /dev/sdX

or

preclear_disk.sh -C 63 /dev/sdX

to convert from one to the other.. (as long as you did not yet assign them to the array just yet)

 

Awesome.  Looks like I used "-A" because it was set to sector 64.  But the other two disks have been assigned to my array since last year and I can't tell what sector they are since they are assigned.  The reports I saved from last year don't have what sector they started on.  I followed the procedures from last year when preclearing a jumpered drive, so I believe they start on sector 63.  Should I got ahead and change the new drive to sector 63 and then add it to the array?  Any risks?

There are no risks to using the "-C" option on a drive not yet installed in the array after being pre-cleared.  It only take s a few seconds to run.  It will not run unless there is an existing pre-clear signature on the disk.

 

If the other two drives are assigned to your array and are jumpered, then just leave them as they are.

 

You can tell their current partitioning by typing:

fdisk -lu /dev/sdX

 

  • Author

Looks like I should be okay then.  Thanks for all of your help!

 

root@unRAID:/boot# preclear_disk.sh -t /dev/sdc

Pre-Clear unRAID Disk /dev/sdc
################################################################## 1.13
Device Model:     WDC WD20EARS-60MVWB0
Serial Number:    WD-WCAZA8305788
Firmware Version: 51.0AB51
User Capacity:    2,000,398,934,016 bytes

Disk /dev/sdc: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1              64  3907029167  1953514552    0  Empty
Partition 1 does not end on cylinder boundary.
########################################################################
========================================================================1.13
==
== DISK /dev/sdc IS PRECLEARED with a starting sector of 64
==
============================================================================

root@unRAID:/boot# preclear_disk.sh -C 63 /dev/sdc

Pre-Clear unRAID Disk /dev/sdc
################################################################## 1.13
Device Model:     WDC WD20EARS-60MVWB0
Serial Number:    WD-WCAZA8305788
Firmware Version: 51.0AB51
User Capacity:    2,000,398,934,016 bytes
########################################################################
Converting existing pre-cleared disk to start partition on sector 63
========================================================================1.13
Step 1. Verifying existing pre-clear signature prior to conversion.  DONE
Step 2. converting existing pre-clear signature:  DONE
========================================================================1.13
==
== Conversion complete.
== DISK /dev/sdc is now PRECLEARED with a starting sector of 63
==
============================================================================

root@unRAID:/boot# fdisk -lu /dev/sda

Disk /dev/sda: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63  3907029167  1953514552+   0  Empty
Partition 1 does not end on cylinder boundary.

root@unRAID:/boot# fdisk -lu /dev/sdb

Disk /dev/sdb: 2000.3 GB, 2000398934016 bytes
1 heads, 63 sectors/track, 62016336 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1              63  3907029167  1953514552+  83  Linux
Partition 1 does not end on cylinder boundary.

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