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VTL vs DSU

Kisad
Level 5

HI,

I moved to a new environment which has both VTL and Disk Storage. This is my first experience of working with VTL's. I understand that VTL  emulate  Tape Drives and Tape Library but are actually disks/storage in the backend.

Now this makes me wonder ,why go the roundabout way of ultimately backing up on a disk (backend of VTL) and take the additional overhead of managing Virtual Media/Drives/Library.Why not simply use the disk storage and backup directly to it. Is there a specific benefit of using VTL.

Please throw some light on this.Thank You.

I'm using Netbackup 6.5 on Solaris 10

PS: I went through the link https://www-secure.symantec.com/connect/forums/use-vtl-or-not-use-vtl-question but it wasnt very clear.

 

TIA

kisad

 

6 REPLIES 6

marekkedzierski
Level 6
Partner

It depends on VTL. If you've got Data Domain, Quantum, Falconstor with deduplication feature you can use OST plugin and threat your hardware as a disk storage with dedup functionality. If you want to duplicate to tape - simply create storage lifecycle policies.

Deepak_W
Level 6
Partner Accredited

VTL -

1. VTL will emulate itself as tape drives. you can create the virtual LTO tapes (any LTO generation), which looks like normal LTO tapes to NBU

2. You can create LTO tapes with barcode, which you want to use in your envoronment

3. Some VTL offer tape export option to physical tape. in this option you can retain barcode schema. For eg. your virtual tape being exported and physical tape will have the same barcode. benifit with this is you can still restore your data from physical tape library (PTL) in case your VTL goes down

4. backup speed is fabulous on VTL as compared to PTL

 

DSU -

1. this is used for staging, or you can have copies on tape and disks both, using SLP probably

2. DSU is local to media / master server. whereas you can zone VTL to any host / NAS to have SAN based backups

 

hope this clears...

 

By the way which VTL you are using??

ChipApple
Level 3
Partner Accredited Certified

Hi Kisad,

My understanding there is no advantage of using VTL over DSU other than a comfort zone for customers who are familar with tape libraries and media.

In many instances, a DSU has to be used anyway in order to take advantage of GRT (Granular Restore Technology) on certain agents such as Exchange, Active Directory and SharePoint.

One challenge you might have is the amount of time that the backup images take to expire before reclaiming the disk space taken by the VTL(s).

Chip

Vapulaflo
Level 4

Sun VTL.... it's a falcon store rebundle and it doesn't works!

Yasuhisa_Ishika
Level 6
Partner Accredited Certified

Most VTL have data compression / deduplication feature that helps you for bulk storage size and compression load. To compress data without VTL's feature, you have to configure client compression that cosumes CPU time on clients.

But, in my tought, cost to purchase, configure and manage VTL is grater than cost for additional disks without compresstion(enough with low-tier SATA disks) and CPU cores on clients, in most case.

Feel free from tapes!

AndreaBolongaro
Level 5
Certified

Hello Kisad, 

I suggest the following links, very useful for me

- Using Virtual Tape Libraries with Veritas NetBackup Software

 

http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_using_virtual_tape_libraries_...

- Netbackup Disk Based data Protection Options

 

http://eval.symantec.com/mktginfo/enterprise/white_papers/b-disk_based_data_protection_options_WP_14...

 

Hope it helps,

 

Andrea