Published: 12 Jul 2006
Newer and not-so-familiar backup products may offer some functional and operational advantages over the big three backup programs.
Free at last. As backup software breaks away from its historically tight integration with tape, less well-known backup products are addressing new priorities, such as closer application integration, backing up directly to disk and encryption. In doing so, they may be a better fit than the big three enterprise backup programs: EMC Corp.'s NetWorker, IBM Corp.'s Tivoli Storage Manager (TSM) and Symantec Corp.'s Veritas NetBackup (see "Big three apps adjust to disk-based backup," Storage, April 2006).
Atempo Inc.'s Time Navigator, for example, includes support for heterogeneous SAN and NAS environments, encryption and hierarchical key management. On the small- to medium-sized business (SMB) side, Symantec's Backup Exec 10d can manage disk-based backups by first staging them on disk for a defined period of time before moving the data to tape.
Complement or replace?
The role of backup software is changing. As organizations consolidate, expand or introduce new applications, there's a growing need to support numerous applications and sites running various underlying hardware and software platforms. As a result, a single enterprise backup software product may not satisfy every application requirement. This is forcing some organizations to reconsider and re-evaluate the role and scope that other backup software products should play in their shop (see "How SMB and enterprise products differ," at right).
|How SMB and enterprise products differ|
As backup software products evolve, the differences between those targeted at enterprises and small- to medium-sized businesses (SMBs) start to blur. Adding to the confusion, vendors like BakBone Software Inc. and CommVault Inc. offer SMB versions of their enterprise products, while others like Computer Associates International Inc. have merged SMB and enterprise products into one product line. Here's how to distinguish between the two classes of products.
Sophisticated management options. Enterprise products will include more powerful ways to manage backup jobs, such as by department or site, and allow policies to be applied to those groups with different administrators getting various levels of control. SMB products generally display all servers on one panel and allow administrators to set policies on only one server at a time, with only one administrator role for all of the servers managed by the backup product.
Tape library and vaulting. SMB products generally provide only basic tape library management functions.
Ease of management. SMB products are easier to manage because they manage less. Backup software vendors recognize that the individuals who manage backup in small shops are usually IT generalists who don't need all of the advanced management functions required by enterprise users.
Platform support. Enterprise products offer a wider array of operating system, database, e-mail and application platform support than SMB products, which generally support only Windows and Linux operating systems and limit integration to Microsoft Corp. products like Exchange, SharePoint and SQL Server.
Expanded product suites. Enterprise backup software products are usually part of a suite of integrated products. Users shouldn't expect third-party integration with SMB backup products.
For example, shops with Network Appliance (NetApp) Inc. filers may want to consider adding another backup product that complements their big three backup products. In instances where users are attempting to do snapshots of dense file systems--file systems that contain millions of small files--Syncsort Inc.'s Backup Express might better satisfy snapshot requirements than products from major enterprise backup software vendors.
Backup Express allows users to overcome the inability of NetApp's native SnapVault snapshot feature to quickly execute snapshots on dense file systems. Executing a native SnapVault snapshot on a dense file system can take 24 hours or longer to complete. Using Syncsort's Backup Express, which includes hooks into NetApp's OS APIs, allows users to complete the same snapshot in seconds.
Another instance where users may want to consider using a lesser-known backup product is remote-office support. Rik Un, a TSM administrator with a Houston-based oil and gas company, is often called on to fly to remote sites to help administrators set up the corporate TSM product. Though Un works with TSM on a daily basis and is a certified TSM administrator, he likes CommVault Inc.'s Galaxy because it takes less time to set up and is more intuitive to manage, even though it lacks some of TSM's features. "TSM's setup and management interface is horrific," says Un.
Shops that make the wholesale switch to another backup software product usually cite multiple reasons for the change. Becky Berg, a system administrator at Farm Credit Services of America in Omaha, NE, was tasked with backing up her company's 47 remote offices to the central office. The firm's existing product, Symantec's Backup Exec, didn't provide her with the ability to accomplish the task at that time. She looked at Symantec's Veritas NetBackup product but found it to be out of her price range.
Berg chose CommVault's Galaxy, which offered all of the features she required and, she says, cost quite a bit less than NetBackup. One feature she particularly likes is the round-robin media agent, which identifies the least-busy tape drive on the firm's Spectra Logic Corp. T10000 tape library and sends the backup job to that tape drive. Berg also plans to use CommVault's QiNetix DataMigrator software, which moves files according to age and last use from primary to secondary storage.
Some backup products geared to SMBs are being enhanced with enterprise-class product features. For example, Symantec made the following improvements to Backup Exec last year:
- Version 10d allows users to do Web-based file recovery.
- Administrators can manage all Backup Exec media servers from a central interface.
- A continuous data protection (CDP) option backs up a server at a remote site and, using a filter driver that runs continuously, sends all file changes to the central office on a schedule set up by the administrator to optimize WAN usage.
Enhanced data protection
Features like CDP, encryption, and disk-based backup and recovery are becoming more prevalent, but there are significant differences in how backup programs deliver these features. For example, products such as CommVault's Galaxy and Symantec's Backup Exec allow administrators to manage CDP within the backup software management interface. Hewlett-Packard (HP) Co.'s OpenView Storage Data Protector uses different interfaces and requires separate logins to manage its backup and CDP databases. Though products like OpenView Storage Data Protector and Atempo's Time Navigator store the CDP data in a different database than the backup data, both HP and Atempo plan to create an index that will allow them to use a federated approach to manage data in the two databases.
|Enterprise backup software challengers: Disk backup options|
|Click here for a comprehensive list of the enterprise backup software challengers: Disk backup options (PDF).|
Other backup software vendors offer CDP, but not in the truest sense of the word. For instance, Atempo has three versions of its CDP product: LiveBackup for PCs, LiveBackup Express and LiveServ for Microsoft Exchange. The first two support only desktops and laptops, while the Express version lacks disaster recovery and system rollback capabilities. Syncsort's Backup Express delivers a type of CDP functionality, although the company doesn't market it as CDP. With Backup Express, administrators may set up a schedule to quiesce applications and capture block-level changes to create a consistent and recoverable system image at various times throughout the day. While not true CDP, it allows users to create recoverable images more often than once a day.
Data encryption capabilities also vary widely. For instance, CA's BrightStor ARCserve Backup includes host-based encryption that allows administrators to specify which files they want to include or exclude from encrypting, as well as what level of encryption they wish to apply to files. However, there are several downsides to using host-based encryption: Turning on encryption requires a password to be set prior to initiating the backup and the password must be available when a restore is done. Second, using host-based encryption increases CPU overhead on the server during backup and recovery, which can affect backup performance. Users also need to verify what levels of encryption the backup software supports and which ones they use. Products such as EMC's Retrospect support an older encryption algorithm, DES-56, which, if used, can be hacked in 35 minutes or less by simply using all possible 56-bit key combinations. Syncsort Backup Express and Symantec Backup Exec plan to incorporate encryption into their products later this year.
As vendors integrate disk into the backup process and claim support for features like disk-to-disk-to-tape (D2D2T), users need to verify how vendors are implementing this functionality. One of the least desirable ways to implement D2D2T is when the backup software treats the disk as a target and dumps the data to disk. This requires the backup software to back up the dump file again from disk to tape, and two restores must be done: first from tape back to disk, and then from disk to the original location. It can also result in the backup software losing track of the dump files and the contents of the files.
|Backup software: Core features|
|Click here for a comprehensive list of backup software: Core features (PDF).|
EMC employs a variation of this approach to centrally manage backup files created by its SMB Retrospect product. Retrospect will back up data on remote-office servers and desktops to disk located in the remote office. Central data centers can then use EMC's enterprise NetWorker to gather the dump files created by Retrospect from the remote offices and store them centrally. However, multiple administrators may need to get involved to restore files because Retrospect may not know where the dump file resides if the remote office's disk copy has been deleted.
A better approach is to spool the data to disk before moving it to tape. Spooled files are temporarily stored in cache memory until moved to tape. The backup software tracks the files the entire time. (When the files are dumped, the backup software assumes the files will be stored on disk permanently; if they're moved, the backup software won't know where the files now reside.) Using disk as a staging area speeds up the backup, but may slow the recovery; if the backup software has already moved the data to tape, users need to recover the data from tape.
Vendors still employ disk caches to satisfy users who execute multiple backup jobs at the same time and send the data directly to a single tape drive, requiring the backup software to multiplex or interleave backup jobs to put all of the data on tape. While this speeds up the backup job and allows the job to complete within the backup window, it also makes recoveries slower since the data is fragmented; it may also cause backhitches, a stop and go of the tape drive, during the recovery.
Atempo's Time Navigator has the ability to defragment large data blocks. It first creates virtual buckets on disk where data from multiple backup jobs is sent. Data from each of the multiple running backup jobs is then separated by individual backup job and put on tape. This eliminates the need to interleave the data on the tape during the backup and improves recovery performance.
A third way vendors implement D2D2T is by first backing up to disk and then managing the creation, movement and retention periods of the backup on different types of media. Keeping a backup on disk for 30 days or 60 days satisfies most user recovery requirements, as most recovery requests will occur within that time period. It also permits the backup software to make a copy of the backup to tape for offsite disaster recovery needs, while allowing the backup software to manage and track the tape so it will know which tape to recall if a recovery is required at a later time. All current versions of enterprise backup software products implement this type of D2D2T, although some SMB products lack these advanced tape library integration and tape vaulting features.
However, one of the most popular ways users implement disk-based backups is by using virtual tape libraries (VTLs). While this approach normally requires the purchase of a separate hardware appliance that bundles the VTL software with it, a couple of backup software vendors offer packages that allow users to circumvent this requirement. Atempo's Time Navigator Virtual Library System (VLS) treats existing storage arrays as a VTL with virtual tapes and allows users to transparently move data between their VTL image and normal tape libraries. BakBone Software Inc. offers a Shared Virtual Tape Library option with its NetVault:Backup product that lets administrators create and share a virtual disk library with multiple NetVault servers to centralize all of the backups in a single VTL.
It behooves you to check out some of the smaller backup software vendors. As traditional ties to tape and tape libraries are broken, products offered by smaller backup vendors may be better architected to handle the new requirements. Obviously, many users are loyal to their familiar backup software and switching to another program may be too daunting a task. Those companies should explore the possibility of using another backup program in a complementary role with their primary backup software to take advantage of new features and possibly cut costs.