PERC 6i and Incorrect drive size

Mon Oct 6 10:30:25 CDT 2008

Is moving drives with Virtual Disks configured between PERC and SAS supported?
That's news for me, is that documented anywhere?

--
Harald

________________________________

From: Elazar Broad [mailto:elazar at hushmail.com]
Sent: Mon 2008-10-06 16:59
To: Jensas, Harald
Cc: linux-poweredge-Lists
Subject: RE: PERC 6i and Incorrect drive size

So that would explain it. The VMWare tech that addressed my
partition issue noted that 431MB was missing from the partition. My
RAID 1 array was originally on a SAS5/iR, I then moved it to a
PERC6/i via the 'Import foreign configuration' option in the PERC
BIOS. Is it safe to assume that the SAS5/iR uses about 80MB or so
for configuration data where as the PERC6/i uses 512 as you
previously stated? As far as I know, moving from a SAS5/iR to a
PERC/6i is supported. Is the PERC controller supposed to rewrite
the partition table?

Thanks,
 Elazar

On Mon, 06 Oct 2008 06:22:32 +0000 Harald_Jensas at Dell.com wrote:
>Hi,
>
>No, most likely not.
>
>This is the info I could find:
>
>
>SAS 5/iR - RAID Disk Data Format = LSI SSP
>
>PERC 5 - RAID Disk Data Format = Common DDF, Profile 1
>PERC 6 - RAID Disk Data Format = Common DDF, Profile 1
>
>
>As you can see the SAS 6/iR does not use DDF, so the SAS 5iR does
>not exhibit the same behavior.
>
>
>--
>Harald Jensås
>
>
>> -----Original Message-----
>> From: Elazar Broad [mailto:elazar at hushmail.com]
>> Sent: 05 October 2008 21:51
>> To: Jensas, Harald
>> Cc: linux-poweredge-Lists
>> Subject: RE: PERC 6i and Incorrect drive size
>>
>> Ah! Thanks Harald! Now let me ask you, does the SAS/5ir exhibit
>the
>> same behavior?
>>
>> Elazar
>>
>> On Sun, 05 Oct 2008 18:26:13 +0000 Harald_Jensas at Dell.com wrote:
>> >Hi Patrick,
>> >
>> >You are seeing 512 MB less space available on each drive when
>> >using the PERC controller. This is because the PERC Controller
>use
>> >the DDF - Data Disk Format.
>> >
>> >DDF is a SNIA standard on how data is formatted on RAID Disk
>> >Groups. The standard specify that a minimum of 32 MB of space
>must
>> >be reserved on each disk in the RAID Group for the DDF
>structure.
>> >In the PERC case the designers decided to reserve 512 MB for
>the
>> >DDF structure, on each disk in the RAID group. I am not sure
>why,
>> >but I guess to be sure not to run out of space when new/more
>> >features are added. Another reason to go for such a large space
>is
>> >to make sure one can keep backward compatibility for a long
>> >time... etc.
>> >
>> >
>> >You can read about DDF here:
>>
>>http://www.snia.org/tech_activities/standards/curr_standards/ddf/S
>N
>> >IA-DDFv1.2.pdf
>> >
>> >
>> >--
>> >Harald Jensås
>> >
>> >> -----Original Message-----
>> >> From: linux-poweredge-bounces at dell.com [mailto:linux-
>poweredge-
>> >> bounces at dell.com] On Behalf Of Elazar Broad
>> >> Sent: 05 October 2008 05:20
>> >> To: linux-poweredge-Lists; Boyd, Patrick
>> >> Subject: RE: PERC 6i and Incorrect drive size
>> >>
>> >> Hi Patrick,
>> >>  Thanks for the reply. I am aware of that. My issue is more
>of
>> >how
>> >> the PERC controller reports the drive size to the OS. Like
>so:
>> >If I
>> >> plug one of the drives into the PowerEdge 1800's onboard
>CERC2/s
>> >> controller, fdisk reports the drive as having
>> >640.1GB/1,250,263,728
>> >> sectors. On the other hand, fdisk on a PERC6i virtual
>> >disk(RAID1)
>> >> reports 639.5GB/1,249,116,159 sectors. What I want to know
>is,
>> >why
>> >> is there 500MB+ missing when using the PERC6i controller?
>> >> Additionally, on a clean install of VMWare's ESXi the
>included
>> >> partedUtil complains about the geometry reported by the
>> >> controller's BIOS.
>> >>
>> >> Elazar
>> >>
>> >> On Fri, 03 Oct 2008 13:35:48 +0000 Patrick_Boyd at Dell.com
>wrote:
>> >> >The drive manufactures measure drive size in base 10, i.e. a
>KB
>> >is
>> >> >1000
>> >> >bytes, a MB is 1000 KB, and a GB is 1000 MB.
>> >> >
>> >> >Software measures drive size in base 2, i.e. a KB is 1024
>> >bytes, a
>> >> >MB is
>> >> >1024 KB, and a GB is 1024 MB.
>> >> >
>> >> >That is the discrepancy that you are seeing.
>> >> >
>> >> >-----Original Message-----
>> >> >From: linux-poweredge-bounces at dell.com
>> >> >[mailto:linux-poweredge-bounces at dell.com] On Behalf Of
>Elazar
>> >> >Broad
>> >> >Sent: Friday, October 03, 2008 3:27 AM
>> >> >To: linux-poweredge-Lists
>> >> >Subject: PERC 6i and Incorrect drive size
>> >> >
>> >> >I know this is slightly off topic. I have a PERC 6i in a
>> >PE1800, I
>> >> >
>> >> >have 2 WD 640GB drives connected to the controller. When
>> >booting,
>> >> >if I hit Ctrl+R to access the configuration utility, both
>> >drives
>> >> >only show as 609620MB as opposed to 640000. Any ideas are
>> >greatly
>> >> >appreciated...
>> >> >
>> >> >Elazar
>> >> >
>> >> >--
>> >> >Financial aid not enough?  Click here for information on
>> >funding
>> >> >your
>> >> >education.
>> >>
>>
>>>http://tagline.hushmail.com/fc/Ioyw6h4fr47sgV1v2eLJxPb08J3E9nEukp
>j
>> >F
>> >> >U87Gn
>> >> >wBUIotXmZhbFX/
>> >> >
>> >> >_______________________________________________
>> >> >Linux-PowerEdge mailing list
>> >> >Linux-PowerEdge at dell.com
>> >> >http://lists.us.dell.com/mailman/listinfo/linux-poweredge
>> >> >Please read the FAQ at http://lists.us.dell.com/faq
>> >>
>> >> --
>> >> Burn fat. Finally, a diet plan that works.
>> >>
>>
>>http://tagline.hushmail.com/fc/Ioyw6h4exb11apa5661hcUxtzh8U8LVZ1kM
>6
>> >A3PohkCTxsi
>> >> ifITY5L/
>> >>
>> >> _______________________________________________
>> >> Linux-PowerEdge mailing list
>> >> Linux-PowerEdge at dell.com
>> >> http://lists.us.dell.com/mailman/listinfo/linux-poweredge
>> >> Please read the FAQ at http://lists.us.dell.com/faq
>>
>> --
>> Go the extra mile with a new pair of running shoes. Click now!
>>
>http://tagline.hushmail.com/fc/Ioyw6h4e3XvqqN4j88JCiOtb4etfaN4pj9L6
>EhakBRvYZwt
>> NXUWZEs/

--
Hotel pics, info and virtual tours.  Click here to book a hotel online.
http://tagline.hushmail.com/fc/Ioyw6h4eRCkmIdopVmJ5JfI2rlz6gK2aWYhTAykZcONvhSMiGs3gLG/