> Thank you in advance.
>
> --
> JG.
>
>
> Le 20 février 2012 14:50, Stan Hoeppner <
stan@hardwarefreak.com> a écrit :
>
>> On 2/20/2012 4:47 AM, Julien Groselle wrote:
>>> Hi,
>>>
>>> I'm trying to understand why this directory is empty :
>> /sys/class/scsi_host/
>>> We have two types of servers, one like that
>>> # uname -r ; cat /etc/debian_version
>>> 2.6.32-5-amd64
>>> 6.0.4
>>>
>>> And other one like that
>>> # uname -r ; cat /etc/debian_version
>>> 2.6.39-bpo.2-amd64
>>> 6.0.4
>>>
>>> On the first one :
>>> # l /sys/class/scsi_host/
>>> total 0
>>>
>>> On the second :
>>> # l /sys/class/scsi_host/
>>> total 0
>>> lrwxrwxrwx 1 root root 0 20 févr. 11:06 host0 ->
>>> ../../devices/pci0000:00/0000:00:1f.1/host0/scsi_host/host0
>>> lrwxrwxrwx 1 root root 0 20 févr. 11:06 host1 ->
>>> ../../devices/pci0000:00/0000:00:1f.1/host1/scsi_host/host1
>>>
>>> It drive me crazy !
>>> Could someone explain me this difference ?
>>
>> The difference is obvious: 2+ years of kernel development between
>> 2.6.32 and 2.6.39--new features added. These are kernel data
>> structures, not files, after all.
>>
>> It's interesting that you know where these kernel data structures are in
>> the filesystem, yet you apparently lack understanding of what they are,
>> and how they get created in the first place.
>>
>>> Second point, why i have this dependency for the package scsitools ?
>>> # aptitude install scsitools
>>> Les NOUVEAUX paquets suivants vont être installés :
>>> libdrm-intel1{a} libdrm-radeon1{a} libdrm2{a} libgl1-mesa-dri{a}
>>> libgl1-mesa-glx{a} libsgutils2-2{a} libutempter0{a} libxaw7{a} libxmu6{a}
>>> libxv1{a} libxxf86dga1{a} libxxf86vm1{a} scsitools sg3-utils{a} tcl8.4{a}
>>> tk8.4{a}
>>> x11-utils{a} xbitmaps{a} xterm{a}
>>
>> Apparently because this system had at one time a GUI environment, or
>> part of one, installed. And I would guess based on this that scsitools
>> has a GUI component available on GUI systems. One of my headless
>> servers with 2.6.38.6 and Debian 6.0.4 shows only 2 dependencies:
>>
>> The following NEW packages will be installed:
>> libsgutils2-2{a} scsitools sg3-utils{a}
>>
>>> drm... mesa... i don't want this on my server, i just want rescan scsi...
>>> I have installed the package on a test server to read the script
>>> /sbin/rescan-scsi-bus, and of course it stop at this line :
>>> for hostdir in /sys/class/scsi_host/host*; do (empty in my case)
>>>
>>> This line was my first hope : echo "No SCSI host adapters found in
>> sysfs" ;
>>> Oh ! sysfs, nice way to search and it was uninstalled on my production
>>> server.
>>> SO i have installed it...
>>> But /sys/class/scsi_host/ is always empty...
>>>
>>> Any help ? :)
>>
>> cciss is a *block* device driver, not a *SCSI* device driver. Thus
>> disks attached to a SmartArray controller cannot be directed accessed
>> via SCSI commands and SCSI tools. Or, at least that's how it used to
>> be. Apparently this distinction has been blurred between 2.6.32 and
>> 2.6.39. It would seem the 2.6.39 cciss driver allows limited direct
>> access/manipulation of devices connected to the SmartArray controller
>> for things such as S.M.A.R.T.
>>
>> --
>> Stan
>>
>>
>>
>