Sata raid questions

I ordered 2 Seagate 160GB 7200.10 7200RPM SATAII/300 8MB Cache - OEM drives
from ebuyer.com UK.

I wanted them to be the same so there would be no issues running them in a
raid configuration. I am a bit miffed as despite ordering them a day apart,
they seem to be different versions as follows:


Drive 1:

Model: ST3160815AS
Part number: 9CY132-501
Firmware: 3.AAA
Warranty expires 30-03-2012 even though delivered today

Drive 2:

Model: ST3160815AS
Part number: 9CY132-304
Firmware: 3.AAC
Warranty expires 16-05-2012 even though delivered today

The models are the same and match what I ordered.

Will the different part numbers and different firmware cause issues?

I would have though ideally it would be best if the drives were identical.

thanks

On Wed, 20 Jun 2007 11:35:18 GMT, "LongJohn"
<not@this.address> wrote:

>I ordered 2 Seagate 160GB 7200.10 7200RPM SATAII/300 8MB Cache - OEM drives
>from ebuyer.com UK.
>
>I wanted them to be the same so there would be no issues running them in a
>raid configuration.

In most cases, they don not need to be the same. Not same
part #, not same firmware version, not same model, not same
manufacturer, not same capacity. That is mostly an urban
myth with one most significant exception, that if you are
defining an array with drives of (even trivially) difference
size, the source drive/initial member of the array upon
which the array size is determined, needs to be the smallest
of all of them.


>I am a bit miffed as despite ordering them a day apart,
>they seem to be different versions as follows:
>
>
>Drive 1:
>
>Model: ST3160815AS
>Part number: 9CY132-501
>Firmware: 3.AAA
>Warranty expires 30-03-2012 even though delivered today
>
>Drive 2:
>
>Model: ST3160815AS
>Part number: 9CY132-304
>Firmware: 3.AAC
>Warranty expires 16-05-2012 even though delivered today
>
>The models are the same and match what I ordered.
>
>Will the different part numbers and different firmware cause issues?

See above.


>
>I would have though ideally it would be best if the drives were identical.


No, there is no ideal that necessarily makes it best if
they're identical, although if you have two drives of
different performance levels, the slower of the two may make
the array slower only by that amount of (performance
decrease), but not because they're different per se (two
different drives having same performance levels each should
be about the same as two identical drives with same
performance levels each), it would still be faster than if
the array were comprised of all identical specimens of that
slower drive. Also if they are different capacity the extra
space on the larger drives is wasted space, though IIRC some
proprietry RAID controllers like Intel Maxtrix type can make
use of the extra space for another separate volume.

In other words, forget what you thought you knew and try
them.

"kony" <spam@spam.com> wrote in message
news:llci731qo3q0907k3dm1rc8d33rne763fp@4ax.com...
> On Wed, 20 Jun 2007 11:35:18 GMT, "LongJohn"
> <not@this.address> wrote:
>
>>I ordered 2 Seagate 160GB 7200.10 7200RPM SATAII/300 8MB Cache - OEM
>>drives
>>from ebuyer.com UK.
>>
>>I wanted them to be the same so there would be no issues running them in a
>>raid configuration.
>
> In most cases, they don not need to be the same. Not same
> part #, not same firmware version, not same model, not same
> manufacturer, not same capacity. That is mostly an urban
> myth with one most significant exception, that if you are
> defining an array with drives of (even trivially) difference
> size, the source drive/initial member of the array upon
> which the array size is determined, needs to be the smallest
> of all of them.
>
>
>>I am a bit miffed as despite ordering them a day apart,
>>they seem to be different versions as follows:
>>
>>
>>Drive 1:
>>
>>Model: ST3160815AS
>>Part number: 9CY132-501
>>Firmware: 3.AAA
>>Warranty expires 30-03-2012 even though delivered today
>>
>>Drive 2:
>>
>>Model: ST3160815AS
>>Part number: 9CY132-304
>>Firmware: 3.AAC
>>Warranty expires 16-05-2012 even though delivered today
>>
>>The models are the same and match what I ordered.
>>
>>Will the different part numbers and different firmware cause issues?
>
> See above.
>
>
>>
>>I would have though ideally it would be best if the drives were identical.
>
>
> No, there is no ideal that necessarily makes it best if
> they're identical, although if you have two drives of
> different performance levels, the slower of the two may make
> the array slower only by that amount of (performance
> decrease), but not because they're different per se (two
> different drives having same performance levels each should
> be about the same as two identical drives with same
> performance levels each), it would still be faster than if
> the array were comprised of all identical specimens of that
> slower drive. Also if they are different capacity the extra
> space on the larger drives is wasted space, though IIRC some
> proprietry RAID controllers like Intel Maxtrix type can make
> use of the extra space for another separate volume.
>
> In other words, forget what you thought you knew and try
> them.
>
OK thanks

I do wonder what the firmware changes were though.