| Q1. |
What is data deduplication and how does it work? |
| A1. |
Data deduplication is a technique for eliminating redundant data from storage, especially from backups. It works by examining the data stream as it arrives at the storage appliance, checking for blocks of data that are identical and eliminating redundant copies. If duplicate data is found, a pointer is established to the original set of data as opposed to actually storing the duplicate blocks - removing or “deduplicating” the redundant blocks from the volume.
It might seem that squeezing more data into less space would mean there's more room to store new data, but that's not how data deduplication works. Because the technology uses pointers to locate repeated data, the ratio of data you can store increases with each backup you make. The ratio of data can depend on the type of data to be stored, the backup methodology and the length of time it is retained.
For more information on data deduplication refer to the whitepapers available on: http://www.hp.com/go/d2d2500.
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| Q2. |
What is Dynamic deduplication and how does it differ from those already on the market? |
| A2. |
There are various methods of deduplication that provide different benefits depending on their usage. For a detailed explanation on these methods please refer to the whitepapers on: www.hp.com/go/d2d or www.hp.com/go/d2d2500.
The HP patented Dynamic deduplication algorithm has been specifically designed for small and medium environments with a focus on compatibility and cost. It includes additional levels of HP reliability for data integrity during backup and restore jobs to deliver:
- Low-cost and small footprint
- A backup format independent solution – so that it is compatible with the majority of backup applications.
Dynamic deduplication works:
- “in-line” with backup, which means that data is deduplicated as it is stored to disk for faster availability (rather than as a separate process once it is on the disk).
- at the block-level within files, rather than “single-instance” which simply removes duplicate files.
For more information on Dynamic deduplication refer to the whitepapers available on: www.hp.com/go/d2d or www.hp.com/go/d2d2500.
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| Q3. |
Is this the same kind of data deduplication used on other HP StorageWorks Virtual Tape Library (VLS) products? |
| A3. |
No. HP has selected different deduplication technologies to meet the differing needs of small and medium businesses to enterprise data centers.
The HP VLS family uses Accelerated deduplication based on object-level data deduplication for increased performance, where the D2D product family employs Dynamic deduplication to meet the requirements of smaller environments for lower cost, smaller size and wider compatibility.
These deduplication technologies are not compatible, they use different technologies and cannot be used together.
For more information on Dynamic deduplication refer to the whitepapers available on: www.hp.com/go/d2d or www.hp.com/go/d2d2500.
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| Q4. |
What data deduplication ratio can I expect to achieve with Dynamic deduplication on the HP StorageWorks D2D2500 Backup System? |
| A4. |
The simple answer is that you can expect to see a reduction in the amount of data between 10x and 50x, however this is very much dependent on the data being backed up, the backup methodology, and the length of time that data is retained. With the backup of a typical business data set over a period of more than 3 months, users might expect to see a deduplication ratio of 20:1 for daily incremental and weekly full backups, or 50:1 for daily full backups.
The important point is that Dynamic deduplication allows you to keep data over a longer period of time on the same disk (more iteration of the same backup data). It does not necessarily allow you to store more unique data or additional data from more servers.
For more information on Dynamic deduplication refer to the whitepapers available on: www.hp.com/go/d2d or www.hp.com/go/d2d2500.
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| Q5. |
Is the HP StorageWorks D2D2500 Backup System a virtual tape library? What advantages does that bring? |
| A5. |
Yes. The D2D2500 Backup System is a virtual tape library and part of the HP virtual tape library range which includes the HP StorageWorks D2D Backup System family and the HP StorageWorks Virtual Library System (VLS) family.
A virtual tape library is a disk-based solution which sits between your server and your physical tape drive/library to provide faster data backup, greater data availability and rapid restores. The D2D2500 product emulates HP LTO tape autoloaders and is recognized by the backup application as one or more physical tape autoloaders (up to 6 for the D2D2500). As compared to other disk-based data protection solutions, the advantages of using a virtual tape library are its ability to leverage and integrate into current backup environments, its ease of setup and management, and its minimal maintenance requirements.
The D2D25000 Backup System is designed and priced for smaller organizations that need to back up no more than six servers. The HP StorageWorks VLS family are designed and priced for medium to large companies and enterprise data centers with many more servers.
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| Q6. |
How does the HP StorageWorks D2D2500 Backup System compare with other products in the HP D2D Backup System family? |
| A6. |
The HP D2D Backup System family is comprised of three product offerings: the D2D100 series, the D2D2500 series, and the D2D4000 series. While each of these solutions utilize HP’s virtual tape library architecture and are built using HP ProLiant server technology, they differ based on capacity, features, and price.
The HP StorageWorks D2D100 Backup System is a series of entry-level D2D solution for small offices in a non-racked environment. It provides automated backup for 6 or fewer servers and is available in raw capacities ranging from 1 TB to 3 TB. Built using a tower form factor, it allows customers to directly integrate an HP LTO tape drive for easy data offload to tape. It connects to a standard Ethernet network using a single iSCSI port and represents HP’s lowest cost solution for upgrading to a D2D backup solution.
Similar to the HP D2D100 Backup System, the HP StorageWorks D2D2500 Backup System also delivers entry-level D2D solution for up to 6 servers with a raw 3 TB disk but it does so in a 1U rack-mount form factor. Other difference include an additional iSCSI port (giving a total of 2x iSCSI ports), faster performance at 75 MB/s, and the Dynamic deduplication feature to provide up to 50x more storage capacity using the same number of hard drives (as compared to the D2D100 series). The D2D2500 is priced just above the D2D100 series.
The HP StorageWorks D2D4000 Backup System is a 2U form factor mid-range solution for larger IT environments or remote data centers in racked environments. It provides backup for up to 16 servers offers a raw capacity range of 4.5 TB to 9 TB. Like the D2D2500 Backup System, the D2D4000 series features Dynamic deduplication, but offers two options for network connectivity: dual-port iSCSI for connection to a standard Ethernet network or dual-port Fibre Channel for connection to a SAN. It is designed for higher performance backup and restore requirements and is priced above the D2D2500 series.
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| Q7. |
Does the HP StorageWorks D2D2500 Backup System support data replication for disaster recovery? |
| A7. |
No, at its launch the D2D2500 Backup System will not support data replication. However this capability is under development for introduction in the near future. |
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| Q8. |
What backup applications is the HP StorageWorks D2D2500 Backup System compatible with and how does my backup software vendor license? |
| A8. |
The D2D2500 Backup System is compatible with most industry leading backup applications.
For more information on current compatibility visit: www.hp.com/go/ebs
Backup software vendors handle licensing differently. Some vendors have chosen to license on a “per TB” basis, while others license as if the virtual devices were physical devices. For more details we recommend that you contact your backup software vendor.
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| Q9. |
Does the HP StorageWorks D2D2500 Backup System mean that I no longer need tape backup? |
| A9. |
No. The D2D2500 Backup System is an excellent solution for daily backup. However, for a robust data protection strategy HP recommends that data is regularly offloaded to physical tape as it provides the most portable, cost-effective technology for:
- Long term archival of data to meet regulatory requirements.
- Off-site storage for disaster recovery in the case of theft, fire, flood or other site-wide disasters.
Using a combination of both disk and tape in a disk-to-disk-to-tape (D2D2T) solution delivers all the benefits of disk for fast data backup and restore, and tape for additional levels of data protection.
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| Q10. |
What physical tape drives are supported and how do I migrate data to tape? |
| A10. |
The HP StorageWorks D2D2500 Backup System supports direct connectivity to HP LTO-2, LTO-3 or LTO-4 Ultrium tape drives. The HP D2D2500 Backup System supports direct connection of the following HP Ultrium tape drives using an appropriate host bus adapter:
HP External LTO-2, LTO-3, and LTO-4 tape drives.
HP Internal LTO-2, LTO-3, and LTO-4 tape drives installed in either a HP 1U or 3U Rack-Mount Kit.
Backup to tape drives, autoloaders and libraries is also available, across the network, using the tape-to-tape (or media copy) feature in your backup.
This allows users to directly offload data (backup jobs) from the D2D2500 to a physical tape drive using the integrated tape export/import features found in the web-based browser interface. Using a directly-connected tape drive with this feature will allow the user to copy data to and from a physical tape cartridge without using any network or server bandwidth. However, HP also supports data copy to network-connected tape devices (via a host or backup server) by using your backup applications tape-to-tape copy (or media copy) function to copy the virtual cartridge from the D2D2500 Backup System to a physical tape cartridge.
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