On 08/18/2009 10:57 AM, Greg KH wrote:
> On Tue, Aug 18, 2009 at 09:59:56AM -0400, Ric Wheeler wrote:
>    
>> On 08/18/2009 09:25 AM, Greg KH wrote:
>>      
>>> On Tue, Aug 18, 2009 at 09:18:30AM -0400, Ric Wheeler wrote:
>>>        
>>>> We have a new toy to test very large&   slow storage with built up from 5
>>>> SAS expansion shelves (Promise Vtrak J-Class) with 60 S-ATA drives and
>>>> 16 SAS drives (the S-ATA drives each have a Promise Vtrak S-ATA MUX
>>>> adapter daughter card in the disk sled).
>>>>
>>>> The basic idea is to build a cheap&   slow test bed for file&   storage
>>>> system scalability. Collectively, we have about 120TB (raw) of capacity
>>>> to play with in one server.
>>>>
>>>> As we work through various issues, a couple of oddities popped out.
>>>>
>>>> The first is that udev grumbles during boot about "file name too long"
>>>> like the following:
>>>>
>>>> Aug 17 06:49:58 megadeth udevd-event[20447]: unable to create db file
>>>> '/dev/.udev/db/\x2fdevices\x2fpci0000:00\x2f0000:00:04.0\x2f0000:17:00.0\x2f0000:18:0a.0\x2f0000:1f:00.0\x2fhost11\x2fport-11:0\x2fexpander-11:0\x2fport-11:0:0\x2fexpander-11:1\x2fport-11:1:0\x2fexpander-11:2\x2fport-11:2:17\x2fexpander-11:3\x2fport-11:3:1\x2fend_device-11:3:1\x2fbsg\x2fend_device-11:3:1':
>>>> File name too long
>>>>          
>>> Odd, what is the sysfs tree for this device?  You have expanders
>>> attached to ports attached to expanders?  How deep can you go?
>>>
>>> thanks,
>>>
>>> greg k-h
>>>        
>> There are two dual-port SAS HBA's in the server that plug into the first of the
>> 5 SAS expansion shelves. Each shelf has two internal SAS loops and is daisy
>> chained to the next shelf....  This test is running with just the first 4
>> shelves active (although that fifth shelf is plugged in, just not used/active).
>>
>> Each of the 60 S-ATA disks sits behind a MUX card which lets it appear on both
>> loops.
>>
>> We could break up the shelves into two independent sets of devices which would
>> limit the tree depth.
>>
>> How can I get you the sysfs tree information in a useful way?
>>      
> 'tree /sys/devices/'
> or
> 'find /sys/devices/'
> would be good.
>
> thanks,
>
> greg k-h
>    

Attached is the bzipped output from - the uncompressed output is quite 
large. Note that this same server has CCIS controllers and fibre HBA's 
as well,

ric