Deduplication on a Master Server - MSDP or Puredisk

[kybeer]

Hi!

Generelly speaking, is Puredisk the best/the only solution for deduplicaion on a Master Server, in a Netbackup 7.5.x environment? I have read here that MSDP is not recommended to run on a Master Server - only on dedicated Media servers.

http://www.symantec.com/business/support/index?page=content&id=HOWTO61249

"- DO NOT configure MSDP on NetBackup (NBU) master servers, OpsCenter servers or servers that are the master and opscenter server. Performance suffers significantly, particularly during busy backup periods."

best regards

johan

[Mark_Solutions]

The same can apply to PureDisk depending on how you set it up

The general rule is that a Master should be a Master when ever possible

Even if using PureDisk the Master would still be performing backups and so using its network etc for those backups as well as, by default, assisting in the fingerprinting of all of the data

Best to keep a Master as a Master when ever possible unless it is an appliance or as powerful as an appliance

[kybeer]

The Master is used for taking backups right now (that's the only server on the main site - the Master, and there's one Media server in a remote site), and is pretty powerfull (I have no real performance issues), if that's what you mean.

So if the hardware in the Master server is fast enough I might as well go with MSDP on it?

[Mark_Solutions]

MSDP will be a greater loading than normal backups.

As an example the NBU Appliances have 12 cores, 6 gb/s SAS disks and 128GB RAM

If your Master can compete with that they you will probably be OK

But as always the best practice is that a Master should be a dedicated Master

You may also need to tune memory and TCPIP as it will be doing a whole LOT more work when you drop MSDP on it.

[kybeer]

Our Master is 6core XEON 3,2GHz with HT, direct atached SAS chassis (synthetic backups run at 400-700MB/s)  and 32GB ram. The CPU load on the Master right now is low. RAM is easily upgraded.

So the thing is really if you want to tax your Master server with deduplication or not? It's not a matter if MSDP or PDDE "works" or not ? Would you say that Puredisk is less taxing than MSDP?

[Mark_Solutions · Accepted solution]

PureDisk involves having a server somewhere else do the work - so yes it will be less taxing on your Master

The trouble is that PureDisk is shortly to go end of life so if you are looking to implement something now i would go for MSDP

It is obviously your choice but if you have a spare server i would load it up with RAM and setup MSDP on that

[kybeer]

Thanks for the reply. I'll see what I can do with MSDP. A while ago saw that there's a reccomended abount of RAM in GB for each TB of storage you deduplicate. Do you know what I mean?

[Mark_Solutions]

Yes - ignore it or at least double it!

It used to (and probably still does) say something like 1GB per TB of disk - so for 30TB of disk you need 30TB of RAM

So if that is OK why would a 64TB maximum Appliance have 128GB RAM?

So try 2GB per TB of disk used for MSDP and you may be OK - then add a bit if it is also going to be the Master Server.

Hope this helps

[kybeer]

Thanks. Is that size in TB for "non-deduped" / "RAW" space, or is it the deduped size? For example, if I have a fileserver with 10TB disk that I need to backup I should have at least 20GB RAM in the server...

[Mark_Solutions]

It is the size of the disk you attach to your server - so if you pop a 10TB volume onto your server to use as your MSDP disk pool ten you need 20GB RAM for it - hope that makes sense

[kybeer]

Yes, thank you.