Mixing 512-byte sector, and 4096-byte sector drives

Mixing 512-byte sector, and 4096-byte sector drives

[Peter Kieser]

Hello,

I have a 6-drive RAID6 of WD15EADS (512-byte sector) drives. One of the 
drives is failing, and I have been forced to buy a WD15EARS (4096-byte 
sector) drive to replace the failing drive, and it has the new "advanced 
format" technology.

Do I need to set the "XP" jumper on pins 7-8 to play nicely with the 
other 512-byte sector drives in my array, or will mdraid be okay with 
the 4096-byte sector drive? Will there be a performance penalty adding 
the drive to my array?

Thank you,

-Peter

Re: Mixing 512-byte sector, and 4096-byte sector drives

[Wil Reichert]

On Mon, Mar 22, 2010 at 4:39 PM, Peter Kieser <peter@kieser.ca> wrote:
> Hello,
>
> I have a 6-drive RAID6 of WD15EADS (512-byte sector) drives. One of the
> drives is failing, and I have been forced to buy a WD15EARS (4096-byte
> sector) drive to replace the failing drive, and it has the new "advanced
> format" technology.
>
> Do I need to set the "XP" jumper on pins 7-8 to play nicely with the other
> 512-byte sector drives in my array, or will mdraid be okay with the
> 4096-byte sector drive? Will there be a performance penalty adding the drive
> to my array?

Did you create your RAID on the device or on a partition?  If its on
the entire device then you should be fine, tho this might depend on
which metadata format you are using & where its located on the disc
(not sure how the metadata effects data alignment).  If you used a
standard partitioning tool its likely your partitions start on sector
63.  This can be confirmed via an fdisk -l on your other drives.  If
that's the case then you'll probably want to use the offest jumper.
How the drive will behave with the others I have no idea.  If after
you add the drive and your write speeds drop dramatically then
something is misaligned.

Wil

Re: Mixing 512-byte sector, and 4096-byte sector drives

[Peter Kieser]

On 3/22/2010 5:11 PM, Wil Reichert wrote:
> On Mon, Mar 22, 2010 at 4:39 PM, Peter Kieser<peter@kieser.ca>  wrote:
>> Do I need to set the "XP" jumper on pins 7-8 to play nicely with the other
>> 512-byte sector drives in my array, or will mdraid be okay with the
>> 4096-byte sector drive? Will there be a performance penalty adding the drive
>> to my array?
>>      
> Did you create your RAID on the device or on a partition?  If its on
> the entire device then you should be fine, tho this might depend on
> which metadata format you are using&  where its located on the disc
> (not sure how the metadata effects data alignment).
>    

I created the RAID directly on the device, I have replaced the drive and 
the new 4096-byte drive seems to be playing nicely with the other drives 
in the array after the resync completed.

-Peter