[Stgt-devel] [PATCH] tgt-admin: support persistent device binding

[Doron Shoham]

Eli Dorfman wrote:
>>> maybe use the following format :
>>> <target xyz>
>>>     <backing-store /dev/sdb>
>>>           properties  custom # use properties specified below or
>>> default (generate the deadbeaf id) or direct (get real serial number)
>>>           serial-number 12345678
>>>           vendor myvendor
>>>     </backing-store>
>>> </target>
>>>
>>> what do you think?
>> Hmm, 'properties custom' looks unnecessary for me. If a device file of
>> a disk drive is used as backing-store and none of the properties are
>> specified, we can use the physical properties.
> 
> we need something like properties to differentiate between disk (read
> real props), file (generate unique serial number
> disk-sn-partition-filename) and custom (applicable to any case).
> we can call this attribute: "type" which can accept 3 values disk,
> file or custom (default).

This is what I suggest:

<target iqn.2007-04.com.example:san.monitoring>
   <backing-store /tmp/ramdisk/lun1>
      type default
      serial 12345678
      vendor my_vendor
      product_id my_id
      product_rev my_rev
   </backing-store>

   <backing-store /dev/sdc>
      type disk
   </backing-store>
</target>

The reason we use XML is that the original implementation used XML.

We suggest two types:
1. disk: "real" physical devices, where we read the properties from the device itself - i.e. storage disks.
2. default - use default tgt values. 
   We can also override the properties with user defined values (optional).

The reason for the type attribute is to differentiate between these two types.

What do you think about it?
If it is agreed by everyone, I'll send a patch.

Thanks,
Doron