Avamar Backup Advantage

A high percentage of data that is retained on backup media by most backup solutions is highly redundant. The typical backup process for most organizations consists of a series of daily incremental backups and weekly full backups.

Daily backups are usually retained for a few weeks and weekly full backups are retained for several months to several years. Because of this process, multiple copies of identical or slowly changing data are retained on backup media, leading to a high level of data redundancy.

A large number of operating system, application files and data files are common across multiple systems in an enterprise. Identical files such as Word documents, PowerPoint presentations and Excel spreadsheets, are stored by many users across an environment. Backups of these systems will contain a large number of identical files.

Additionally, many users keep multiple versions of files that they are currently working on. Many of these files differ only slightly from other versions, but are seen by backup applications as new data that must be protected.

Backing up redundant data increases the amount of backup storage needed and can negatively impact network bandwidth. Organizations are running out of backup window time and facing difficulties meeting recovery objectives due to the need to manage backup versions and a myriad of backup tapes.

Avamar differs from traditional backup and restore solutions by identifying and storing only unique, sub-file data objects. Redundant data is identified at the source, drastically reducing the amount of backup data that travels across the network to be stored and managed by the backup host. When storing data objects, Avamar takes maximum advantage of inherent hard-disk characteristics. Avamar also creates and stores “trees” that link all data objects from a single backup. These “trees” are used to re-create files for restore.

Avamar RAIN

Avamar supports two basic types of standard Avamar server configurations, which are:

- Non-RAIN and 

- RAIN.

Non-RAIN configurations consist of a single stand-alone node. In single node configurations, both utility and data functions are provided. Non-RAIN configurations require replication. (Previous versions of Avamar supported 1x2 servers consisting of 1 utility and two data nodes).

RAIN configurations include one utility node, three or more data storage nodes, and a spare data node. Currently, the largest standard configuration consists of 16 data nodes, 1 utility node, and 1 spare data node. A minimum RAIN configuration is 1x3 server.

In a multi-node system, the nodes operate together as one server. The hostname and the IP address of the utility node are the identity of the Avamar server for access and client/server communication. Avamar load balances data across all available nodes in a server. With node architecture, Avamar can be easily scaled by adding more nodes.

Avamar Replication

Avamar replication is a feature that transfers data from a “source” Avamar server to a “destination” Avamar server. All data in the destination server can be directly restored back to primary storage without having to be staged through the source Avamar server.

You can use either Avamar Administrator or Avamar Enterprise Manager to manage your replication settings.

Efficient Data Transfers. Replication is accomplished by way of highly efficient, asynchronous Internet Protocol (IP) data transfers, which can be scheduled during off-peak hours to make optimum use of network bandwidth.

Additionally, like other members of the Avamar product family, replication uses sophisticated data de-duplication technology that finds and eliminates redundant sequences of data before it is sent to the destination server, thereby reducing network traffic and promoting efficient use of hard disk storage.

Remote Branch Disaster Recovery. Replication enables the efficient replication of data stored in a single-node server to a multi-node server. Using replication, a distributed enterprise can centrally protect and manage multiple remote branch offices that are using individual single-node servers for local backup and restore. The centralized multi-node server can then be used for disaster recovery, in the event of catastrophic data loss at any remote branch office.

Enterprise Data Center Disaster Recovery. Replication can also be used to replicate data stored in a multi-node server to any other multi-node server in your enterprise. In this manner, multi-node servers can provide peer-to-peer disaster recovery for each other.

Avamar Data Deduplication

Data Deduplication
Avamar differs from traditional backup and restore solutions by identifying and storing only unique, sub-file data objects. Redundant data is identified at the source, drastically reducing the amount of backup data that travels across the network to be stored and managed by the backup host. When storing data objects, Avamar takes maximum advantage of inherent hard-disk characteristics. Avamar also creates and stores “trees” that link all data objects from a single backup. These “trees” are used to re-create files for restore.

Data deduplication, or single instance storage, reduces storage needs by identifying duplicate or redundant data. Only unique data is then stored on the storage media. The level at which data deduplication is employed determines the granularity of deduplication. Three levels of data deduplication are:

File level deduplication helps organizations reduce storage needs for file servers by identifying duplicate files within hard disk volumes and providing an efficient mechanism for consolidating them. The most common implementation of single instance storage is at the file level. With this method, a single change in a file results in the entire file being identified as unique. As shown in the example, if there were 5 versions of a file in a backup environment, the 5 files in their entirety are stored.

Fixed block deduplication, also called fixed length deduplication, is commonly employed in snapshot and replication technologies. This method breaks a file into fixed length sub-objects. However, even with small changes to the data, all fixed length segments in a dataset can change despite the fact that very little of the dataset has actually changed.

Variable block level deduplication uses an intelligent method of determining segment size that looks at the data itself to determine repeatable boundary points. Variable block level deduplication yields a greater granularity in identifying duplicate data, eliminating the inefficiencies of file level and fixed block level deduplication. With variable block level deduplication, a change in a file results in only the variable-sized block containing the change being identified as unique. Consequently, more data is identified as common data, and in the case of backup, there is less data to store as only the unique data is backed up. This is the method used by Avamar.

Avamar Components

In an Avamar system, what makes up the system are the following 3 major components.  They are Avamar server, Avamar backup clients, and Avamar Administrator.

Avamar Server 
- Client backups are stored on this server.  This server provides essential processes and services required for client access and remote system administration. Take note that the following processes: Avamar Administrator Server (mcs) and Avamar Data Server (gsan) run on the Avamar server.

Avamar Client Software
- After software installation on the clients, Avamar client software runs on each computer or network server that is being backed up. This provides client software for various computing platforms. Each client consists of a client agent and one or more plug-ins.

Avamar Administrator Console
- This console software is installed on any supported Windows or client computer. which is able to access the Avamar system on the network.  From then on, this user management console software application is used to remotely administer the Avamar system.

Avamar Checkpoints

Avamar Checkpoints
Checkpoints are system-wide backups taken for the express purpose of assisting with disaster recovery. Checkpoints are typically scheduled twice daily and validated once daily (during the maintenance window). You also can create and validate additional server checkpoints on an on-demand basis.

Checkpoint validation, which is also called an Avamar Hash Filesystem check (HFS check), is an internal operation that validates the integrity of a specific checkpoint. Once a checkpoint has passed an HFS check, it can be considered reliable enough to be used for a system rollback.

The actual process that performs HFS checks is hfscheck; it is similar to the UNIX fsck command.

You can schedule HFS checks by using Avamar Administrator. You also can manually initiate an HFS check by running avmaint hfscheck directly from a command shell.

An HFS check might take several hours depending on the amount of data on the Avamar server. For this reason, each validation operation can be individually configured to perform all checks (full validation) or perform a partial "rolling" check which fully validates all new and modified stripes, then partially checks a subset of unmodified stripes.

Initiating an HFS check requires significant amounts of system resources. To reduce contention with normal server operation, an HFS check can be throttled. Additionally, during this time, the server is placed in read-only mode. Once the check has been initiated, normal server access is resumed. You can also optionally suspend command dispatches during this time, although this is not typically done.  If HFS check detects errors in one or more stripes, it automatically attempts to repair them.

Avamar - Clients Agents Plug-ins

Avamar clients
Avamar provides client software for various computing platforms. Each client comprises a client agent and one or more plug-ins.

Agents
Avamar agents are platform-specific software processes that run on the client and communicate with the Management Console Server (MCS) and any plug-ins installed on that client.

Plug-ins
The following topics provide details on the two types of Avamar plug-ins.

File system plug-ins
File system plug-ins are used to browse, back up, and restore files or directories on a specific client file system. Avamar currently provides plug-ins for the following operating systems:

• Free BSD
• HP-UX
• IBM AIX
• Linux
• Mac OS X
• Microsoft Windows
• Microsoft Windows Volume Shadow Copy Service (VSS)
• SCO OpenServer
• SCO UnixWare
• Oracle Solaris
• Novell NetWare
• VMware

Application plug-ins
Application plug-ins support backup and restore of databases or other special applications. Avamar currently provides plug-ins for the following applications:

• IBM DB2
• Lotus Domino
• Microsoft Exchange
• Microsoft Hyper-V
• Microsoft Office SharePoint Server (MOSS)
• Microsoft SQL Server
• NDMP for NAS devices, including EMC Celerra IP storage systems and Network Appliance filers
• Oracle
• SAP with Oracle
• Sybase ASE

Avamar Encryption

Avamar Encryption

To provide enhanced security during client/server data transfers, Avamar supports two levels of “in-flight” encryption: Medium and High. The exact encryption technology and bit strength used for any given client/server connection depends on a number of factors, including the client platform and Avamar server version.

The default encryption method is used for client/server data transfers (None, Medium, or High) when you create and edit groups.  The group encryption method can also be overriden for a specific client on the Client Properties tab of the Edit Client dialog box, for a specific backup on the On Demand Backup Options dialog box, or for a specific restore on the Restore Options dialog box.

To enable encryption of data in transit, the Avamar server data nodes each require a unique public/private key pair and a signed X.509 certificate that is associated with the public key.

When the Avamar server is installed, a public/private key pair and a self-signed certificate are generated automatically in the /data01/home/admin directory on each Avamar server storage node and in the /usr/local/avamar/etc directory on the utility node. However, because self-signing is not recommended in production environments, you should generate and install a key and signed certificate from either a commercial or private CA.

Each individual Avamar server can also be configured to encrypt data stored on the server “at rest.” The decision to encrypt all data stored in an Avamar server is typically a one-time decision that is made when the server is initially deployed at a customer site.

Avamar NDMP Accelerator Node for NAS

Avamar NDMP Accelerator Node

The limited scalability of traditional single system NAS platforms has been well documented as an issue.  Less well documented are the issues that can arise when the backup and recovery process can't keep up with the growth.

That is where the Avamar NDMP Accelerator node come in,  it support multiple storage devices and up to 8 simultaneous streams, performing real-time data dedupe.  Of course, there needs to be sufficient RAM and configuration on the accelerator. It supports VNX, Celerra, and NAS devices running Data ONTAP.  It supports NDMP version 4 over 100/1000 Mb/sec Ethernet and will work over a LAN or WAN.

The NDMP backups contain all storage device accounting information and ACLs.  Only volumes are visible, and include/exclude lists are not supported.  When combined with VNX or Celerra, the NDMP accelerator performs incremental backup at the volume level only and defaults to full backup of sub-root directories.  Best practice is to not backup more than 10 million files in a single backup job, which can be overridden in the config but jobs may fail for lack of memory with too many files.

When backing up NetApp Filers, the NDMP accelerator is backward compatible to Avamar 4.1 servers, but version 5.0 or newer is recommended.  The appliance will backup and restore volumes, qtrees and directories, and SnapVault snapshots must be backed up in full.

The NDMP accelerator will perform file level restores, as well as single directories and sub-directories, but data backed up on other Avamar client types are not restorable to a NAS - if it came from NDMP, it stays on NDMP and vice-versa.  There is no web restore with external authentication - users must have local authentication, and ACLs are fully supported, but there is no control for overwrite options.

Both LAN and WAN location of the NDMP device are supported, but it is recommended to have the accelerator local to the device being protected.   8 GB of memory is required in the appliance for multiple streams, and the recommendation is to have 4GB of memory per stream (8 streams max).

Multi-volume accounts will attempt to backup all volumes simultaneously, opening up to the possibility that there would be too many simultaneous streams.  It is best practice to combine all multi-volume accounts into one account and have a single multi-volume backup using the avsetupndmp script.

Avamar and VMware

Avamar software quickly and efficiently protects VMware Infrastructure environments by reducing the size of backup data within and across virtual machines - using agents in the virtual machines or on the VMware vStorage APIs for Data Protection proxy server.

For virtual machine backups, Avamar eliminates traditional backup bottlenecks caused by the large amount of redundant data that must pass through the same set of shared resources - the physical server's CPU, Ethernet adapter, memory, and disk storage.

Avamar reduces the traditional backup load - up to 200 percent weekly - to as little as 2 percent over the same day period, dramatically reducing backup times and resource utilization.

Key Avamar benefits include:

• Up to 10x faster daily full backups
• Up to 500:1 reduction in required daily network bandwidth
• Up to 50:1 reduction in required global backup storage media
• Encryption of backup data in flight and at rest
• Fault tolerance across Avamar nodes and elimination of single points of failure using the patented RAIN technology
• Scalable grid architecture
• Daily server integrity and data recoverability checks
• Simple one-step recovery
• Flexible deployment options, including EMC Avamar Data Store and EMC Avamar Virtual Edition for VMware (a virtual appliance)
• Improved physical server consolidation rations

Avamar Integration with Data Domain

Starting from Avamar release v6.0 onwards, not only comes with more new features, Avamar provides support for integration with Data Domain.

On the hardware side, this release offers higher density nodes with greater performance. Nodes are now offered in 4 different capacities: 1.3 TB, 2.6 TB, 3.9 TB, and 7.8 TB. The standard Utility and Accelerator nodes continue to be available and serve the same function in Avamar v6.0 as they did in previous releases. What is more, is the performance of the node relative to important internal system maintenance and upkeep scales with capacity. The 7.8 TB node offers twice the performance of the 3.9 TB node. For some important tasks like garbage collection and file system checks this means there is no longer any good reason not to use the highest density nodes even for data with exceptionally high change rates.

Even better, prices have declined while capacities have gone up-in some cases the cost per TB has improved by more than 20%. And the power consumption per TB has also dropped considerably-by as much as 65% in the case of the 7.8 TB nodes. All this equals bigger grids which cost less to acquire, less to power and cool in the data centre, and use less of your valuable raised floor square footage to store data.

Under the covers there are lots of significant performance improvements to the new nodes to make sure that things work better than before: EMC has leveraged the Intel multi-core architecture to speed up startup and checking of data stripes. Memory utilization is improved, and overall backup performance increases.

One of the biggest changes that many customers willnotice will be the changes to the networking architecture. The lines between internal and external networks are no longer blurred. There is a network that is clearly an internal management and administration network (which is redundant). And customers will connect an Avamar grid to their external network to provide for backup bandwidth and redundancy if desired. (As an aside, for those of you that want Cisco everywhere in your network, it is now possible to connect your Avamar Data Store nodes directly to your Cisco network. You can maintain the homogeneity of your IP network and continue to manage and support only Cisco devices.)

On the software side, the improvements are every bit as significant:

• Support for EMC Secure Remote Support (ESRS)
• A new installer/updater service for client and server code upgrades and patches that is customer accessible
• An Avamar client manager that enables management of large groups of clients with a single pane of glass, and allows wizard driven task execution against groups of clients. (Another aside: it also allows moving a client or a group of clients from one Avamar grid to another. For those of you managing large numbers of desktop and laptop clients, or desktop and laptop clients for a globally distributed workforce, this will be a particularly welcome addition that will make administration a lot easier.)
•  Overall, there have been a least a dozen significant enhancements (and many minor updates) to the desktop and laptopbackup experience with the Avamar DT/LT client that will make Avamar easier, faster, more flexible, and easier to support for these environments. From an end user perspective, the self-service recovery window has been improved, which is a welcome upgrade. From an administrative point of view, the administration of large numbers of clients has been made easier too.
• Improvements have been made across a wide range of general clients, and specific modules, including the backup of Oracle systems, Oracle RAC systems, NDMP backups, backups for Iomega ix12 systems (a very cool feature which essentially puts an Avamar client on the Iomega storage system for powerful remote backup of these systems), VMware Image Backup enhancements, Windows 2008 server backups, SQL server systems, Exchange backup, and a host of others. I will return to the topic of Windows applications backup and VMware backup in the near future, because there is enough good stuff there to warrant a separate discussion.

And, to leave the best for last: Avamar is now offering integration with Data Domain systems.

With release 6.0 of the Avamar software, EMC will now support Data Domain systems as a backup target. This combines the performance and scale of the Data Domain systems with the ease of use and simplicity of the Avamar software. Now any application, of any size, can be protected with Avamar. And the scale of Avamar grows very significantly-with the addition of up to 285 TB of capacity per Data Domain system (and up to 4 systems supported per Avamar server).

In the initial release, EMC is supporting the backup of Oracle, SQL, Exchange, SharePoint, and VMware Images to Data Domain systemswith Avamar software. The Avamar GUI will manage the backup, restore, and replication of data for these systems, as well as monitoring and reporting on the Data Domain systems that are the backup targets. Avamar clients get an embedded DD BOOST v2.3.1, which is responsible for actually sending the backup data from the client to the target Data Domain system. Now, even very largedatabases and database with very high daily change rates can be easily integrated into Avamar.

Overview of Avamar

Overview of Avamar - Avamar Node Types and Processes
There are several different types of Nodes within an Avamar Server.

Utility Node - The identity of the Avamar Server which provides the bulk of the internal Avamar server processes such as: Avamar Administrator (used to manage the Avamar Server from a gui), cron jobs, DNS, NTP, external authentication, web access, MCS and EMS.

Storage Node - This node run a process called gsan.  This service communicates with the avtar command on the individual backup clients.  Avtar communicates with a storage nodes gsan process, then that storage node spreads the data across the available data nodes.

Spare Node - An active node that  is present in a multi-node RAIN (Redundant Array of Independent Nodes) grid.  The interesting thing about the Spare Node is that it is NOT a hot spare.  There is a procedure in place that needs to be followed when a failed Storage Node occurs.  In fact, the Avamar Server doesn’t even care if the Spare Node is powered on, so if you are a “Green” conscience company, feel free to leave the Spare Node powered down.  EMC Best Practice is to leave the Spare Node up and active though.

Avamar Backups clients can be installed with 2 different types of client plug-ins: File System and Databases.  The Avamar client uses 2 processes in the backup and restore process: Avtar and Avagent.  The Avagent process listens for backup/restore work orders from the MCS service on the Utility Node using port 28002 and executes the avtar command that handles the backup/restore processes and communicates with the gsan service on the storage nodes.  This process is depicted in the included picture above.

MCS (Management Console Server) provides centralized management including scheduling of backups, restore of backups, monitoring and reporting.

EMS (Enterprise Manager Server) provides web based management for multiple Avamar Servers as well as monitoring and configuration for Avamar Replication.

Web Access provides access to documentation, backup plug-ins as well as remote File System  restore access to end users.

EMC Avamar Deduplication

EMC Avamar enables fast, efficient backup and recovery by reducing the size of backup data at the client—before it’s transferred across the network and stored. Avamar's variable-length deduplication dramatically reduces network traffic by only sending unique blocks, compressed and encrypted over local area networks (LANs) or wide area networks (WANs). Blocks that were previously stored are never backed up again.

Avamar is a sourcebase global deduplication solution which enables fast, efficient backup and recovery by reducing the size of backup data at the client before it is transferred across the network and stored. Avamar’s data deduplication dramatically reduces network traffic by only sending unique blocks over LAN/WAN. Blocks that were previously stored are never backed up again.

This means huge savings in bandwidth for backup, a lot less disk storage needed on the back end, and most importantly very fast backups often as much as ten times faster.

Avamar backups can be quickly recovered in just one step eliminating the hassle of restoring full and subsequent incremental backups to reach the desired recovery point. Backup data is encrypted during transit across the network and at rest for added security.

There are three ways to define data deduplication:

File-Level 
File level deduplication reduce storage needs for file servers by identifying duplicate files and providing an efficient mechanism for consolidating them. The most common implementation of single instance storage is at the file level. With this method, a single change in a file results in the entire file being identified as unique. Example: If there were 3 versions of a file in a backup environment, the 3 files in their entirety are stored.

Fixed Block 
Fixed block deduplication is commonly employed in snapshot and replication technologies. This method breaks a file into fixed length sub-objects. However, even with small changes to the data, all fixed length segments in a dataset can change despite the fact that very little of the dataset has actually changed.

Variable Block 
With variable block level deduplication, a change in a file results in only the variable-sized block containing the change being identified as unique. Consequently, more data is identified as common data, and in the case of backup, there is less data to store as only the unique data is backed up. This is the method used by Avamar

What is Avamar - EMC's top selling backup solution

EMC's top selling backup solution Avamar has a refreshing new twist on the backup world. Avamar utilizes backup to disk hardware and client software installs to create a client-server network backup/restore solution while using a unique de-dupe technology.

Traditional backup solutions have some significantly inherent problems. A high-percentage of data that is retained on backup solutions is redundant data. Typical strategies consist of daily incremental backups and weekly full backups. These backups can be very time consuming, especially when getting the full backups, and yield multiple copies of identical or slowly changing data on backup media. This media then has to be organized and kept off-site for disaster recovery purposes, which often leads to high protection service costs, and high recovery time objectives. In addition, the data itself that is often duplicated across several servers in the case of system files, and many users keep identical or slightly different versions of the same documents. Traditional backups will backup all copies and variations as if they were brand new documents. Backing up redundant data increases the amount of backup storage needed and can negatively impact network bandwidth. The backup window for most organizations gets smaller and smaller the more they grow.

Avamar differs from traditional backup and restore solutions by identifying and storing only unique data objects. Redundant data is identified at the source, which reduces the amount of data that actually needs to travel to the backup server node. Avamar utilizes a chunk and hash methodology to break down all files into smaller chunks of data to send to the backup node. Unique hashes are generated from this data that gets stored on the backup node. If a client tries to send the same data, the backup node will respond that it already has that data and does not need another copy. Only new, modified, or changed chunks from the original files will be sent to the backup node.

Key Features:

• Global data de-duplication ensures that data objects are only backed up once across the backup environment.
• Systematic fault tolerance, using RAID, RAIN, checkpoints, and replication provides data integrity and disaster recovery protection.
• Highly reliable inexpensive disk storage for primary backup storage.
• Standard IP network technologies. Optimizes use of network for backup, does not require a separate backup network.
• Centralized management. The Avamar Administrator and Enterprise consoles give users full-featured remote management of Avamar servers with robust reporting capabilities.

Support for Windows, Unix, Linux, NDMP, SQL, Exchange, DB2, and Oracle.
So now that you have some of the basics, check back soon to get a more in depth look to how the different solutions are deployed. There are 3 basic versions:

Avamar Data Store Non-RAIN (single or multiple nodes with replication)
Avamar Data Store RAIN (multiple data nodes for fault tolerance)
Avamar Virtual Edition (virtual appliances versions in .5 and 1 TB)