VIO SERVER BASICS

virtual I/O is the term used to describe the ability to share physical I/O resources across partiotions.


physical resouces that are being shared are adapter cards located in pci-x slots of managed system.


vioserver software runs on seperate partitions. which is created using HMC.






benifits of vio server


partitions can be created without requiring additional physical adapter.


 suppose you are having 3 ethernet adapters in your P570 box. and you have planned to create 12 partiotions. it means you need 12 physical ethernet adapters for this that means extra cost . because of this only vio server came into picture. by using vio server if you are having only one ethernet adapter that is enough and is assigned to vio server .  in this scenario you can create 12 virtual ethernet adapter through HMC  and assign to the partitions.


going to aix environment


$help  - it is very useful  .it will show you list of commands used in vio server .


$oem_setup_env


you will get #prompt. now you can run aix commands




to view the mapping

$ lsmap -all

SVSA            Physloc                             Client Partition ID
--------------- -------------------------------------- ------------------
vhost0          U8234.ZMA.0123494-V5-C22            0x00000006

VTD                   vtscsi0
Status                Available
LUN                   0x7100000000000000
Backing device        abhivg_rootvg

Physloc

VTD                   vtscsi44
Status                Available
LUN                   0x8800000000000000
Backing device        hdisk99
Physloc               U7311.i20.063CD7C-P1-C02-T1                                                                                                

SVSA            Physloc                            Client Partition ID
--------------- -----------------------------------------------------
vhost1          U8234.zmc.01234C94-V5-C22          0x00000001

VTD                   NO VIRTUAL TARGET DEVICE FOUND

here, you see the  vhost0, vhost1 these are the adapters corresponding to particular partition.

here , vhost0  corresponds to partition id 6

         vhost1  correspond to partition id 1

VIRTUAL TARGET DEVICE(VTD)

it can be logical volume,PV or a file that you are assigning  to particular  partition by mapping that with the related adapter(vhost). 

here for vhost0  ,

 a VTD  is defined named vtscsi0 which is backed by logical volume "abhivg_rootvg"

also vtscsi44 which is backed by hdisk99 attached to vio server.


how to map the VTD to particular partition.






1.create a logical volume of the required size you want to map.


$mklv -lv abhilv rootvg 5G
abhilv available


#lsvg -lv rootvg

2. map the logcal volume to particular adapter(vhost#) associated to the particular partition using "mkvdev" command.

$ mkvdev -vdev abhilv -vadapter vhost3 -dev abhi_disk

abhi_disk Available

in this command the following parameters are used,

-vdev -  to specify  the backing device

-vadapter - the adapter corresponding to particular partition you want to map

-dev - to give the name for VTD

$ lsmap -vadapter vhost3

SVSA            Physloc                       Client Partition ID
--------------- ------------------------------- ------------------
vhost3          U8234.EMA.0688C94-V5-C24      0x00000007

VTD                   abhi_disk
Status                Available
LUN                   0x8100000000000000
Backing device        abhilv
Physloc   


how to remove the virtual target device
            
$ rmdev -dev abhi_disk  or $ rmvdev -vtd  abhi_disk
abhi_disk removed



$lsmap -vadapter vhost3

SVSA            Physloc                            Client Partition ID
--------------- -----------------------------------------------------
vhost3         U8234.zmc.01234C94-V5-C22          0x00000007

VTD                   NO VIRTUAL TARGET DEVICE FOUND