Celerra Disk Reconfiguration and Advanced Management

EMC Proven Professional Knowledge Sharing 2011 James Ingle Design Architect Alexander Open Systems [email protected]

Table of Contents Article Summary ...... 3 Reasons for Backend Disk Reconfiguration ...... 3 Process for Backend Disk Reconfiguration ...... 3 Additional Information on NAS Volumes and Disk Usage ...... 5

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Summary The EMC ® Unified Storage Platform is a very flexible storage system when it comes to connectivity and data management. Due to the tight integration of EMC Celerra with EMC CLARiiON®, storage administrators are able to provide a scalable storage solution for any network infrastructure. While setup and basic administration of the EMC Celerra is quick and simple, reconfiguring the back end storage and following best practices takes some consideration.

While it is extremely easy to add disks and expand storage with the Celerra, what happens when you change directions with your storage design and wish to reconfigure the CLARiiON storage behind the Celerra data movers? There is a specific process that must be followed using the graphical (GUI) and/or the command line interface (CLI). Additionally, there are caveats that must be considered when deleting the underlying volumes, disks, LUNs, and RAID groups that make up Celerra storage.

Reasons for Backend Disk Reconfiguration  Protocol or Connectivity Change – The decision to convert from iSCSI to NFS or Fiber Channel  Infrastructure Change – New feature, application, or acquisition may require different capacity and performance characteristics  Performance Tuning – Adjust RAID type or disk configurations for storage tiering and performance

Process for Backend Disk Reconfiguration 1) Access Celerra using SSH/Telnet/CLI and log in using nasadmin (ensures proper environment variables and paths for commands used in this procedure) 2) Use navicli or Navisphere/Unisphere to identify the physical disks and/or RAID Groups that you wish to reconfigure a. CLI Command: $ /nas/sbin/navicli -h "sp_ip_address" getdisk –all 3) Identify the File Systems and Storage Pools in use on the Celerra a. Use Celerra Manager or Unisphere to identify the file systems utilized by iSCSI LUNs, NFS Exports, and CIFS File Shares 4) Identify the Storage Pools that the File Systems reside on a. via GUI: View the Properties of the File System b. via CLI: $ nas_fs -info "file_system_name" 5) Identify the Volumes that the Storage Pools reside on (Volumes are labeled d7, d8, d9...) a. via GUI: View the Properties of the Storage Pool b. via CLI: $ nas_fs -info "file_system_name" 6) Identify the Raid Groups and LUNs that the Volumes reside on a. via CLI: $ /nas/tools/.whereisfs -all

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7) Perform a full backup of all data to be migrated 8) Migrate the data to a temporary location or file system a. Use Celerra Replicator or manual copy tools (xcopy / robocopy / emcopy / rsync) 9) Delete any File System Checkpoint storage that is in use on designated disk space 10) Delete the File Systems that are no longer in use a. via GUI: Right-click or select desired File System and select Delete b. via CLI: $ nas_fs -delete "file_system_name" -Force 11) Verify that the Volumes that the Storage Pools reside on are no longer in use (will have 'n' in the 'inuse' field) a. via CLI: $ nas_disk -l 12) If a Volume still shows that is in use after all of the File Systems have been deleted, run the shrink command to remove the disk from use on the Storage Pool a. CLI Command: $ nas_pool -shrink "storage_pool_name" -volumes "volume_name" 13) If User-Defined Storage Pools have been created, they may be deleted. System-Defined Storage Pools may NOT be deleted. a. via CLI: $ nas_pool -delete "pool_name" -deep 14) Delete the Volumes that reside on the disks and/or RAID Groups that you wish to reconfigure a. via CLI: $ nas_disk -delete "disk_name" -perm 15) Use navicli or Navisphere/Unisphere to remove LUNs from the Celerra Storage Group a. CLI Command: $ /nas/sbin/navicli -h "sp_ip_address" storagegroup -removehlu "LUN_ID" 16) Use navicli or Navisphere/Unisphere to unbind the LUNs and then delete the RAID Groups a. Unbind LUNs: $ /nas/sbin/navicli -h "sp_ip_address" unbind "LUN_ID" -o b. Delete RAID Group: $ /nas/sbin/navicli -h "sp_ip_address" storagegroup -removerg "rg_ID" -o 17) Verify that no LUNs have been trespassed during or before the previous steps (trespass back to default owner if necessary) a. CLI Command: $ /nas/sbin/navicli -h “sp_ip_address” getlun -default -owner 18) Rescan the storage system after the change to discover the available disks a. via GUI: Rescan Storage System b. via CLI: $ server_devconfig server_2 -c -s -a 19) Provision the unused storage as needed 20) Migrate data from temporary location to new storage pool space and file systems

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Additional Information on NAS Volumes and CLARiiON Disk Usage

Celerra Disk Table The Celerra File Server stores the volume or disk IDs in a disk table or database that allows the system to keep track of the backend storage. When a LUN is added to the Celerra Storage Group on the CLARiiON array, the Celerra File Server is allowed to access and manage that LUN. When a Celerra storage rescan or discovery process is executed to find recently added storage, several steps occur:

1) Celerra initiates discovery process 2) LUN is discovered 3) A volume name or disk ID is created for the LUN and added to the disk table a. NOTE: The volume name appears as d7, d8, d9… 4) The LUN description is changed in the CLARiiON and follows the following naming scheme a. LUN X becomes Celerra_NAS-NAME_LUN-ID_DISK-NAME b. Example: LUN 16 = Celerra_NS120_16_d17 5) The volume is then labeled based on the RAID type for storage pool assignment a. Example: LUN 16 is a 4+1 RAID5 Raid Group on 300GB FC drives. When added to the Celerra, it is labeled as: clar_r5_performance b. NOTE: If Automatic Extension is enabled, the useable space of the volume will automatically be added to the clar_r5_performance storage pool. If this happens, it is still possible to add it to a User-Defined storage pool as long as it is not in use (see step 9.a below for checking if disk is in use) c. NOTE: See the latest Celerra Release Notes for recommended disk configurations for backend CLARiiON storage on Celerra File Servers.

The Celerra Disk Table keeps track of all of the disks that are added, changed, or removed from the Celerra. The disk names stored in the Celerra Disk Table are assigned once and never deleted. Disks d0 thru d6 are used for the Celerra data mover system files and should never be moved, changed, or deleted. If one of these disks is modified accidentally, please contact EMC Support. The actual user storage begins with d7 and goes up. If at any time you delete a disk from the Celerra Disk Table, the disk name d7 will not be used again. Instead the next disk number in line will become the next disk name, such as d8.

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