[Webinar] Streamline your web hosting managementRegister Today

  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1548
  • Last Modified:

NetVault Backup

I want to know which option is better

Netvault backup with  Tape Libray


NetVault backup with NAS/SAN
3 Solutions
Depends on what your needs are.

If you don't need to keep data for more than a year, if you are happy having all your backup data at the same site as your business data, and if you'll never be audited by the IRS (or equivalent local taxing agency) or sued over a contract, then you may be able to  get by with backing up to disk alone.

If you have an unlimited budget so that electricity costs and HW acquisition costs don't bother you, you may be able to get by with just disk.

Numerous studies have shown that a D2D2T (disk to disk to tape) strategy is much cheaper than just D2D -- and it provides for an easy way to get your data offsite, as well as to maintain it for extended periods of time.

If the law or your business practices say that you have to keep data for fie or ten years or longer, the likely best fit is a mixture of D2D2T for servers that backup slowly or require frequent restores, and D2T for servers that stream the backups well and don't need frequent  restores.
venkataramanaiahsrAuthor Commented:
Generally the feeling is tape backup is obsolete and i am given the task to choose between
Dell TL4000 LT05/06 Tape library  and San storage  for back up solution.  Approximate current size of backup data is around  20TB. (Mostly Radiology Dept data - images)

Can you pls explain the pros and cons of the same
Gerald ConnollyCommented:
Tape backup is NOT obsolete, there are numerous papers/studies out there to show that it isn't, and beside this there a numerous reasons why you should use tape.

Remember that HDDs are not designed to sit on a shelf not working for extended periods like tape is.

Radiology images, I suspect you have to keep them for some considerable time, I think it's something like 30 years after a patient dies in some countries!
Never miss a deadline with monday.com

The revolutionary project management tool is here!   Plan visually with a single glance and make sure your projects get done.

David Johnson, CD, MVPOwnerCommented:
In an ideal world you would have both SAN and Tape (two different media)

The accepted rule for backup best practices is the three-two-one rule. It can be summarized as: if you’re backing something up, you should have:

    At least three copies,
    In two different formats,
    with one of those copies off-site.
Connolyg's explanation -- given that you have patient medical information -- is exactly what I was hinting at.   Disk may initially *seem* either cheaper or easier -- but a few  years down the road you'll start to see just how expensive it is to keep this kind of data on disk.

Data on the tapes can be easily compressed, without losing performance, and gaining some additional capacity.
The tapes can be easily encrypted, without losing backup performance or capacity.
The tapes can be stored on a shelf for five years or more without loss of data -- at which time you can go through them according to policies, laws, and regulations, and move data you still are required to keep to the then-current generation of tape.

Disk is not designed to keep data when stored without power for years -- in fact, no disk manufacturer says anything about how long the data on an unpowered disk will be good.  Tape is designed to store data and be reliably read for 20 - 30 years or more.  

Tape doesn't require more than the most basic of HVAC control when not being read or written to -- and maybe an occasional manual rotation to keep the tape from sagging.
Disk requires being powered up and spinning in order to maintain its data.  And the power used is heat, and you have to move the heat out of the data center somehow, which is more electricity for air conditioning.

Consider the HP MSL 2024 tape library instead of the Dell.  HP has a tool called Tape Assure that can give you real-time metrics on tape drive performance, tape health, compression ratios, etc.  In addition, HP's tape drives have a much better implementation of adaptive write speed -- a continuously variable implementation, vs. IBM's end-of-track, which means your tapes and drives will last longer and be more reliable.  
http://www.hp.com/go/msl   will get you what you need.

Now -- it's possible that you have to do frequent restores of some servers, or, that you have some servers that can't stream data fast enough to keep your tape drives spinning.  In that case, you might want to implement a disk-to-disk-to-tape strategy, staging the slow servers on disk before copying that data to tape.  In addition, this helps you with your backup strategy because it gives you at least two  of the three copies you want, and two of your different media, and the tape can be your off-site option.

If a full backup takes too long (for whatever "too long" means to your business), another option is to consider using HP Data Protector software, which has an Incremental Forever with Synthetic Full backup option.  This means you do one full backup to disk, then all incremental backups to disk after that (and the incremental backups then will be very quick and almost always meet your backup window requirements).  When you require a full backup on tape for offsiting, you create a synthetic full, which uses the backup application catalog to pull the files from your disk pool as if you'd done a full backup at the point of your last incremental backup.  Then you ship the tape to wherever you store them.  This technology is particularly valuable for either systems with lots of small and tiny files in a deep directory structure that can't be backed up fast enough to meet their window, or, for customers with lots of data that tends to not change much, but the huge amount of data makes it silly to perform a standard full backup when so little has changed.
venkataramanaiahsrAuthor Commented:
Thanks every body for sharing this excellent information which really helped me in finalizing  my decision on backup options

Featured Post

[Webinar] Kill tickets & tabs using PowerShell

Are you tired of cycling through the same browser tabs everyday to close the same repetitive tickets? In this webinar JumpCloud will show how you can leverage RESTful APIs to build your own PowerShell modules to kill tickets & tabs using the PowerShell command Invoke-RestMethod.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now