It has generally come to my attention that for consultants especially there is a lack of knowledge surrounding Celerra and the fact that from EV7, files can be archived. I have threrefore put together this quick, simple article in regards Celerra components and how EV works with Celerra so terminilogy etc can be understood.

What is it…? - Models, Components, Terminology

- A NAS/SAN Device for File Storage.
Comes with many different options in terms of hardware and software. A bit like Enterprise Vault!

• The Celerra product line
• Celerra NS series
• Celerra NS40 and NS80
• Celerra NSX series
• Celerra Clustered Network Server

Core Components

• Data Mover
• Control Station
• Storage system
• Network connections
• Component naming conventions

Each component is now covered in a little more detail below.
Data Mover

• For data transfer
• 1-14 Data Movers
• Referred to sometimes as a Blade
• Active/Standby  
• Independent
• Communication to key components

Control Station

• Management
• Monitoring
• EMC Customized Linux OS

Storage system

• Array of Physical Disks
• Type can vary depending on the Model/Symmetrix or CLARiiON disk arrays.

Networking

Located on Data Mover
Number of NIC’s dependent on model
Ethernet or fibre
Component naming conventions

• Data Movers are named based on where they are located in the Celerra Network Server cabinet. The name can be changed.
• Network ports are named based on the type of NIC and the position of the port on the NIC. This name cannot be changed.

Requirements prior to archiving to EV

• Data Mover, File System, CIFS Server and CIFS Share are setup and configured.
• Enterprise Vault 7 or above required to support placeholders on a Celerra.
• Data Mover to be running Dart 5.5 or above.
• IP Addresses to be used for each CIFS Server to configure in DNS.

How it works (BAckground Process) Enterprise Vault for File System Archiving creates files called “Placeholders”. On Windows this is achieved using a Windows File System Filter Driver.
This would not work with Celerra so how does Enterprise Vault do it?

• Enterprise Vault uses an API named the Celerra FileMover API to create placeholders.
• The Data Mover credentials stored in FileServerEntry table in SQL in Directory Database.
• Download.asp is used to recall data.

Setup
Covered in the following technote which you will find linked to in the Install and Config Guide for EV8.
http://entsupport.symantec.com/docs/289676

Gotchas
The URL of the Enterprise Vault Web Access Application is for example http://EVServer.demo.local/EnterpriseVault. The EV Server defined needs to be the one that the FSA Archiving Task/Storage Service is running on.  For example if you have two EV servers ServerA and ServerB and ServerB processes the Celerra then the URL will need to point to this server.  If this does not happen then data will be archived however placeholders will not recall correctly and you will receive a 500 error.  The reason is the request will go to the wrong EV server.

Also in the URL use the Alias for the Vault Server concerned whenever possible.

Remeber also the URL is case sensitive and if this is incorrect you see a "No Matching Connection" logged in FSA Reports and Dtraces. Tip is to check the SiteEntry (If only one EV Server in use) or the Computer Entry table to ensure correct case is used.

If still receiving no matching connection use a HTPP trace utiliy like Fiddler to capture request and see what the URL EV is trying to use including case in use and compare this to what is set on the Celerra.

Proxy Servers can sometimes cause issue so if possible bypass these.

Celerra transfers data in three ways. EV supports FULL!!
1. Full - The complete item is recalled in 32KB chunks from the beginning to the end of the file.
2. Partial – The file is recalled in 32 KB Chunks until a point in the file depending on how the user is using the file.
3. Pass-through – The file is recalled in random 8 KB chunks.
To set full on a file system use the following command.
fs_dhsm -modify File System -read_policy_override Full

Full – Partial – Pass-Through?
To check which option is being used use the following command

FS_DHSM –INFO FileSystemName

Backup and Anti-Virus Scanning

Useful Technotes - There are ofcourse more available via support site,
http://support.veritas.com/docs/304712
'Failed to check Placeholder state on EMC Celerra volume' is generated when adding a Celerra volume as a target in File System Archiving

http://support.veritas.com/docs/292572
Celerra and Delete on Delete and Delete on Recall Behavior for Enterprise Vault 7.0 and Enterprise Vault 2007.

http://support.veritas.com/docs/304532
Alternate Data Streams (ADS) are being created on a Celerra Target

http://support.veritas.com/docs/316271
How to view placeholder metadata for placeholders that reside on an EMC Celerra device

http://support.veritas.com/docs/289810
GENERAL ERROR: "Error 5005 : Failed to Complete Command" is returned on a Celerra Device.

http://support.veritas.com/docs/316523
Slow placeholder recalls of large files on EMC Celerra