Hi All

 

I have been running 4.7 for a long while now and generally pretty happy with it. I have the following disks...

 

Parity  - 2Tb Seagate ST32000542AS

Disk 1 - 1Tb Samsung HD105SI

Disk 2 - 2Tb Hitachi HDS5C302

Disk 3 - 1Tb Western Digital WD10EARS

Disk 4 - 1Tb Western Digital WD10EARS

Disk 5 - 2Tb Western Digital WD20EARS

 

So a bit of a mixed bag... for a while now the Hitachi drive keeps 'failing' - it goes to a red spot and is effectively dead. The first time this happened I panicked and thought I was about to lose everything - but after checking the disk it seemed that there was nothing wrong with it. Anyway - every time it fails now, I unassign the disk, reboot Unraid, Hitachi appears with a blue spot, re-assign it and it rebuilds and then all is fine for a few more weeks.

 

This is just to let you know why I have decided to change the disk - I am thinking its probably some random incompatibility... so today I bought a Western Digital 2Tb WD20EZRX to replace it... annoying as I thought the Hitachi drive was 1Tb so this would be an upgrade Anyway I was just about to pre-clear it ready to install it and came across a Wiki which says to set the Default partition format to MBR - 4k aligned. Mine is set to MBR unaligned.

 

http://greenleaf-technology-howtos.blogspot.co.uk/2011/02/how-to-preclear-your-hard-drives-for.html

 

Anyway reading this Wiki it kind of reads that this should be done on a new installation and doesn't say whether changing settings on a live server will muck things up... so I thought I would see what others think as I don't really understand this parameter and don't know what it should be set to on my unit - hence the drive details. Also if I do change it - does that mean all my drives have to be re-precleared to benefit and if so, could I do them one at a time to ensure that I don't lose any data??

 

So - any advice or thoughts greatly appreciated

 

Thanks

All new drives should be 4k-aligned.

Thanks dgaschk

 

So if I change this setting will it cause any problems as the drives were installed with unaligned setting, or should I be able to change it to 4k and all will be well?

 

Incidentally, I have just started pre-clearing the new 2Tb drive using the -A flag as this seems to be right for 4k alignment 

 

KR

There is no effect on existing drives. This will produce no observable effect on your system. The -A option is not required once the unRAID system is set to 4k-aligned; it will have no effect.

Thanks