This directory contains disk systems intended as targets for backups. There is a separate directory for disk targets for archives.
Note: IBM announced 4/17/08 that they are purchasing Diligent. This makes the future of the current IBM product (based on Falconstor) and the HDS product (based on Diligent) unclear. While both vendors have stated that they will continue to support existing customers, it is unclear how this will affect long term viability of these products.
| Vendor/Product
| Original Vendor
| VTL, NAS,
or Local
| Integrated or
Standalone
| Appliance,
Gateway,
or Software
| De-dupe
| In-band or
Out of band
| Dedupe Domain
| Dedupe Method
| Open-Storage API
|
| See definitions of these column names
|
| COPAN
| FS=COPAN
VTL=Falconstor
| VTL & NAS
| Integrated
| Appliance
| On VTL
| Out-of-band
| Global
| Hash
| ?
|
| Data Domain
| Data Domain
| VTL & NAS
| Standalone
| Appliance & Gateway
| Yes
| In-band
| Local
| Hash
| Yes
|
| Diligent ProtecTier
| Diligent
| VTL
| Standalone
| Software
| Yes
| In-band
| Local
| Delta Diff
| ?
|
| Diligent VTL Open
| Diligent
| VTL
| Standalone
| Software
| No
| N/A
| N/A
| N/A
| ?
|
| EMC EDL
| Falconstor
| VTL
| Integrated
| Appliance
| No
| N/A
| N/A
| N/A
| ?
|
| EMC DL 3D
| Quantum
| VTL,NAS
| Integrated
| Appliance
| Yes
| Policy
| Local
| Hash
| ?
|
| Exagrid
| Exagrid
| NAS
| N/A
| Appliance
| Yes
| In-band
| Local
| Delta Diff
| ?
|
| Falconstor
| Falconstor
| VTL
| Integrated
| Software
| Yes
| Out-of-band
| Global
| Hash
| ?
|
| Gresham Clarita VTL
| Gresham
| Integrated
| Software
| No
| N/A
| N/A
| N/A
| N/A
| ?
|
| Fujitsu-Siemens CentricStor
| Fujitsu-Siemens
| Integrated
| Appliance
| No
| N/A
| N/A
| N/A
| N/A
| ?
|
| HDS VTL
| Diligent
| VTL
| Standalone
| Appliance
| Yes
| In-band
| Global (2 nodes)
| Delta Diff
| ?
|
| HP VTL
| SEPATON
| VTL
| Standalone
| Appliance
| Yes
| Post-process
| Global
| Delta Diff
| ?
|
| IBM VTL
| Diligent (IBM)
| VTL
| Standalone
| Appliance
| Yes
| Inline
| Global (2 nodes)
| Delta Diff
| ?
|
| NEC Hydrastor
| NEC
| NAS
| N/A
| Software
| Yes
| In-band
| Global
| Hash
| ?
|
| NetApp Nearstore VTL
| NetApp
| VTL
| Integrated
| Appliance
| Yes
| Post-process
| Local
| Delta Diff
| ?
|
| NetApp NearStore
| NetApp
| NAS
| N/A
| Appliance
| Yes
| Out-of-band
| Local to Flex-vol
| Hash + bit compare
| ?
|
| Overland Reo
| Diligent
| VTL
| Standalone
| Appliance
| Yes
| In-band
| Local
| Delta Diff
| ?
|
| Quantum DXi
| Quantum
| VTL, NAS
| Integrated
| Appliance
| Yes
| Policy
| Local
| Hash
| ?
|
| SEPATON
| SEPATON
| VTL
| Standalone
| Appliance
| Yes
| Out-of-band
| Global
| Delta Diff + others
| ?
|
PureDisk Storage Unit
(Only works with NBU)
| Symantec
| LFS
| N/A
| Software
| Yes
| In-band
| Local
| Hash
| Yes
|
| Sun StorageTek VTL
| Falconstor
| VTL
| Integrated
| Appliance
| Yes
| Out-of-band
| Global
| Hash
| ?
|
Legend
- VTL, NAS, or LFS
- Is the target a virtual tape library (VTL), Network Attached Storage (NAS), or a locally attached filesystem (LFS)
- Integrated or Standalone
- If the VTL will copy its virtual tapes to physical tapes in a library connected behind it, the it is considered an :Integrated tape library. If you must use your backup software's traditional way for copying backups from one tape to another in order to copy data from virtual tape to physical tape, then it's a Standalone VTL.
- Appliance, Gateway, or Software
- An appliance is a complete system containing a head and all necessary disk. A gateway is a server head provided by the vendor that is ready to plug into disk of your choice. Software products do not provide any hardware, although they may specify certain system types that are certified with their software.
- De-dupe
- Does the product identify and eliminate redundant data
- In/Out of band
- If the product does deduplication, is the redundant data identified and eliminated before it ever hits disk (i.e. in-band, also known as in-line or synchronous), or does the product write the backup to disk, then have a separate process read and deduplicate it?
- Dedupe Domain
- The bigger the amount of data that is compared against each other, the better the deduplication ratio, especially in a multi-appliance environment. Many deduplication appliances dedupe data only against other data stored within a single filesystem or in the storage connected behind a single head (i.e. local dedupe.) Some dedupe appliances can accept data from multiple heads and still de-dupe all data against all other data, regardless of which head it comes into (i.e. global dedupe).
- Dedupe method
- One of the methods for identifying redundant data is the creation of a SHA-1 or MD5 hash. If two blocks of data have the same hash, they are deemed identical. For a heated debate on the merits of the "hash collision" issue, check out this thread in the NetBackup forum. Another method is delta differencing, where tonight's backups are simply lined up against last night's backups and compared bit-for-bit. This is a very old technique - the difficulty now is in using this methodology against backups from various sources. (Traditional delta differencing systems did so within the backup software.)
- Open-Storage API
- To say YES in this column, the vendor must support Symantec's Open-Storage API, which is designed to control intelligent disk target devices from NetBackup.