Please help - adaptec 2820sa not ... RESOLVED

Scott Long scottl at samsco.org
Mon Jun 19 16:20:42 UTC 2006


Eric Anderson wrote:
> Ensel Sharon wrote:
> 
>>
>> On Mon, 19 Jun 2006, Jahilliya wrote:
>>
>>>> Ok, aac is in the dmesg.
>>>>
>>>> I can see both 2820sa cards in the dmesg, and I see no errors, etc. -
>>>> there are just no drives listed in dmesg.
>>>>
>>>> My setup is 8 500 Gb drives in a single raid-6 array, size ~2.8TB.  Any
>>>> problems with that ?  Perhaps sysinstall cannot deal with a >2TB drive
>>>> ?  There are no other drives in the system besides the single 2.8TB 
>>>> raid 6
>>>> array ...
>>>>
>>> Have you got any other drives you can attach to the raid?
>>>
>>> If so, disconnect the 8 drives connected, connect up a couple that are
>>> not part of the raid and configure them as a simple raid 1 and see if
>>> the installers sees that raid. Or try any combination in drives to
>>> bring the raid size down below 2TB (I'm sure this limitation has been
>>> fixed.)
>>
>>
>>
>> Ok, the answer is that it has not been fixed.
>>
>> 6.1 sysinstall does in fact see both 2820sa controllers, and when I 
>> put in
>> a single 160GB sata drive, it does see that single drive and I can 
>> install
>> onto it, etc.
>>
>> Sysinstall does _not_ see my 2.7TB raid6 array.  I suspect that if it 
>> were
>> smaller than 2TB, it would see it correctly.
>>
>> I have a number of options with which to deal with this, all of which
>> involve either wasting money or wasting disk space.  Fantastic.
> 
> 
> Right - FreeBSD doesn't recognize >2TB LUNs.

Wrong on several counts.  First, the AAC driver does not present arrays 
to the system as SCSI LUNs.  The traditional 2TB limit with 12 byte CDB
issue simply doesn't exist with this driver.  Second, the FreeBSD SCSI
layer knows how to issue 16 byte CDBs to access >2TB, assuming that the
target understands the 16-byte protocol.  So no, there is no 2TB limit
inherent to FreeBSD.  The only limit is with individual drivers and with
hardware.

Scott




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