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7.6 new install - How best to configure Storage Units / Disk Pools

Created: 15 Aug 2014 • Updated: 21 Aug 2014 | 11 comments
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Hi all,

We have a fresh install of with three servers: Master, Media & OpsCenter.  We have two storage devices that are both connected to the Media server using iSCSI.  Both devices appear as single large Volumes (30TB). The storage devices are geographically isolated but will each contain exactly the same data.

We are licensed to use NetBackup Data Protection Optimization and are wondering how best to configure the Storage.  Is it OK to simply create one large 30TB Storage Unit & Pool per device and backup up everything to them or shoud we divide the storage up per type of data e.g. a pool for SQL backups, a pool for Exchange backups, etc?  Are there any recomendations?

Coming from HP Data Protector where we used D2D units it was best practice to have the same type of data on each seperate dedupe store..

Many thanks in advance,


Operating Systems:

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Riaan.Badenhorst's picture

You can only have 1 dedupe pool configured on a MSDP.


Riaan Badenhorst

ITs easy :)

INT_RND's picture

You can easily make a disk pool of 64TB with MSDP but the problem is having a media server that is powerful enough to handle the fingerprint database calculations and transactions. I recommend reading the system requirements in the dedupe storage guide:

I see no benefit to making different pools for different types of data. The more data you put in the better chances you have of fingerprint matching which means better dedupe rates. There are some things that don't dedupe well. Databases for example will take up more space in your dedupe pool than other types of data. If you have partitions in your disk then you might end up running out of space in your database pool. Then what? stop doing database backups while you have plenty of free space in the other disk pool? This doesn't make sense to me. Capacity planning with dedupe storage is difficult because you can't really predict how much space your data will use. You must do some testing and it will take some time to get to your maximum dedupe rate.

BirtyB's picture

Both helpful answers - many thanks chaps.

I wil review the dedupe guide.

INT_RND's picture

Please mark the thread as solved if you have found the answer.

BirtyB's picture

Actually, Riaan's comment has just made me realise that what we are trying to do may not be possible.

As I said previously, we would like to attach two storage devices to a single media server and have exactly the same data on both units (deduped).  How best might we achive this?

Thanks, Graham

INT_RND's picture

You could make one logical volume out of them in a RAID 1 mirror set. Then both disks would contain identical infromation automagically. 

If you do this within the OS of the media server it's called a "Software RAID" because you're not actualy using a RAID controller to create the volume. 

BirtyB's picture

Yeah that would be one way of doing it.

What about replication?  If we concentrate on backing up data to volume A can we then replicate this data to Volume B.  Does NBU support this?

Or I suppose we could turn the Master server into a Media server and have  storage unit connected to each server...

It just seems odd that a single Media server can only host a single dedupe store.

INT_RND's picture

The software RAID would be the easiet. If you wanted duplicate images between two disk pools they would both need to be configured as MSDP and then you can use SLP to duplicate images to the other pool on a schedule. This adds a bunch of extra jobs and copy operations. It would take more time and have the possibility for complications.

The reason you need a media server dedicated to the MSDP pool is because of the managing of the dedupe database. Data deduplication is extremely complex. Again, see the system requirements for a dedupe media server. One MSDP pool can fully untilize 8 CPUs, 32GB of RAM and multiple teamed NICs. There are also I/O considerations. I seen servers that are using 96GB of RAM and it's not going to waste.

What sort of hardware do you have in your media and master server? 

Marianne's picture

Raid protection for the MSDP volume(s) is a no-brainer. Raid-1 or Raid-5 will be fine.

Symantec also recommends to duplicate MSDP to alternate storage - it can be another MSDP pool on another media server or to tape. 
All of this in Dedupe Admin Guide referred to in previous excellent posts.

Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links

Riaan.Badenhorst's picture

We have two storage devices that are both connected to the Media server using iSCSI.  Both devices appear as single large Volumes (30TB). The storage devices are geographically isolated but will each contain exactly the same data.


The mirroring is not going to be a good idea as you'll have latency between the local and the remote  site, which means your writes will be affected.

I suppose you want to have the data on both devices for DR purposes. The best option would be to install another media (and master) at the remote site and use AIR (automated image replication) to replicate it. You could get away with running the master and media on the same server if its powerful enough (and if its a cold site that wont do backups).


Riaan Badenhorst

ITs easy :)

Mouse's picture

Something to note about iSCSI volumes and MSDP. These are only supported when you can achieve 130MB/s R/W on these volumes from your media server and the volume but more importantly, you have to achieve sub 10ms latency which usually only doable with 10GBps Ethernet/LAN .