Friday, June 26. 2009

How to Mask Paths in vSphere

You can prevent the ESX/ESXi host from accessing storage devices or LUNs or from using individual paths to a LUN. Use the vSphere CLI commands to mask the paths. When you mask paths, you create claim rules that assign the MASK_PATH plugin to the specified paths. Via Kevin Kress the master of VMkernel and Console Config and esxcfg-* tools.

Procedure

1	. Check what the next available rule ID is.

esxcli corestorage claimrule list

The claim rules that you use to mask paths should have rule IDs in the range of 101 – 200. If this command shows that rule 101 and 102 already exist, you can specify 103 for the rule to add.

2	. Assign the MASK_PATH plugin to a path by creating a new claim rule for the plugin.

esxcli corestorage claimrule add -r <claimrule_ID> -t <type> <required_option> -P <MASK_PATH>

For information on command-line options, see esxcli corestorage Command-Line Options.

3.	Load the MASK_PATH claim rule into your system.

esxcli corestorage claimrule load

4.	Verify that the MASK_PATH claim rule was added correctly.

esxcli corestorage claimrule list

5.	If a claim rule for the masked path exists, remove the rule.

esxcli corestorage claiming unclaim <type> <required_option>

6.	Run the path claiming rules.

esxcli corestorage claimrule run

After you assign the MASK_PATH plugin to a path, the path state becomes irrelevant and is no longer maintained by the host. As a result, commands that display the masked path's information might show the path state as dead.

Example B‑5. Masking a LUN

In this example, you mask the LUN 20 on targets T1 and T2 accessed through storage adapters vmhba2 and vmhba3.

#esxcli corestorage claimrule list

#esxcli corestorage claimrule add -P MASK_PATH -r 109 -t location -A vmhba2 -C 0 -T 1 -L 20
#esxcli corestorage claimrule add -P MASK_PATH -r 110 -t location -A vmhba3 -C 0 -T 1 -L 20
#esxcli corestorage claimrule add -P MASK_PATH -r 111 -t location -A vmhba2 -C 0 -T 2 -L 20
#esxcli corestorage claimrule add -P MASK_PATH -r 112 -t location -A vmhba3 -C 0 -T 2 -L 20

#esxcli corestorage claimrule load

#esxcli corestorage claimrule list

#esxcli corestorage claiming unclaim -t location -A vmhba2
#esxcli corestorage claiming unclaim -t location -A vmhba3

# esxcli corestorage claimrule run

How to Mask Paths in vSphere

Eric Sloof

Friday, June 26. 2009

How to Mask Paths in vSphere

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