PROVISIONING A LUN/STORAGE TO HOST IN DMX

Provisioning LUN from a storage to host involves a simple process to follow. First we need to understand the requirement and then we start the actual process. Here we deal with only STD Devices and meta devices formed from STD devices. Thin device creation and virtual provisioning will be discussed later for DMX4 and VMAX

In provisioning  LUN(/storage) to host process below steps are involved

1) CREATING DEVICES 

devices may be individual STD devices or Meta devices formed by combining two or more STD devices. we will discuss about different types of devices later this

post for now we stick to provisoning STD/meta devices in DMX 3/4

2) MAPPING

   Devices that we created needs a path to assign them to a host. so we map them to symmetrix front end ports and the process is called mapping

3) MASKING

  so we have devices(LUNs) created for host and prepared a way to access. then what is masking and why we need this? when we map the devices to a front end port, all the hosts which are zoned to a front end port  will have access to all LUNs or devices we created and mapped to that port. so to provide secure way of accessing a particular device/LUN by particular host we require masking them.

lets jump into the actual process through solutions enabler SYMCLI


let our requirement is 4x100gb concatinated meta luns protection is raid 5 (3+1) host name: windows host_wwn: 1000000000123

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1)  CREATING DEVICES

a) STD device creation:

step1:  Check if any configuration lock

$symconfigure -sid 1234 verify

abort any running/hault config lock

$symconfigure -sid 1234 abort


step2: check the free space in array

$symconfigure -sid 1234 list -freespace -units MB


step3: create std devices

first create a file "dev_create.txt" with the following command


create dev count=16 size=25gb config=RAID-5 data_member_count=3 emulation=FBA disk_group=2;

$symconfigure -sid 1234 -f dev_create.txt commit -v -nop

this command will create devices of 25 gb. lets say the devices are 0001:000F,0010

 b) CREATE META DEVICES

first create a file "meta_create.txt" with below commands

form meta from dev 0001 config=concatinated
add dev 0002:0004 to meta 0001

form meta from dev 0005 config=concatinated
add dev 0006:0008 to meta 0005

form meta from dev 0009 config=concatinated
add dev 000A:000C to meta 0009

form meta from dev 000D config=concatinated
add dev 000E:0010 to meta 000D


now run the configuration command to create meta device

$symconfigure -sid 1234 -f meta_create.txt -v -nop commit

now we have created 4x100gb meta device

Lets check the devices which we created just now or anytime we can search free devices in the storage array using

$symdev -sid 1234 list -noport


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2) MAPPING

lets check what are front end ports

$symcfg -sid 1234 list -fa all

Now lets check on which FA port the host logged in ( from the requirement session we will sure have either or both host name and host wwn)

$symmask -sid 1234 list logins -wwn host_wwn

We have the front end port where the host logged in now we need to find the available address for LUN on the front end port. let 7c port 0 is our front end directory/adaptor

$symcfg -sid 1234 list -available -address -dir 7c -p 0

##now from the output find the available address##

mapping the devices to front end port

we can map one device at a time so it is better to create a file ( map.txt ) with mapping commands for all devices then we map all of them with a single command

map dev 0001 to dir 7c:0 lun=123 target=0;
map dev 0005 to dir 7c:0 lun=124 target=0;
map dev 0009 to dir 7c:0 lun=125 target=0;
map dev 000D to dir 7c:0 lun=126 target=0;


$symconfigure -sid 1234 -f map.txt -v -nop commit

 we are done with mapping devices to front end ports. lets check the mapping

$symmask -sid 1234 list no_assignment -dir 7c -p 0

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3) MASKING

masking is a straight forward one and have a single step

$symmask -sid 1234 -wwn 10000000000012 -dir 7c -p 0 add devs 0001,0005,0009,000D

to update the info in VCMDB

$symmask refresh


With this we done with the provisioning the storage to a host.  In my next post I will explain you what are the types of different  devices available in symmetrix DMX 3/4 and also VMAX.


Thank you
Rajesh Para