HP B6200 Synthetic Backups

[Kev_Lamb]

Hi,

I have read on the forum that using Synthetic backups with the HP StoreOnce OST Plug-In is not supported, HP have also confirned this, they are looking to push for the support, I have created an NFS share on the StoreOnce B6200 and have set this up as an Advanced Disk and Storage Pool and can successfully run some test Synthetics using this method.

Having spoken to HP they do not reccomend using NBU with the NFS(NAS) shares for Synthetic backups, this maybe a push from them to get DataProtector in the door (over my dead body) but I would like to know if anyone is using any of the HP StoreOnce products with NFS shares and using Synthetic Backups and if they have encountered any problems using this method?

We currently use a VLS12000 and are looking to get rid of Virtual Libraries and start using OST and as we are an HP hardware house the B6200 met that requirment but we also have a need for synthetic backups so were looking to split the B6200 into OST and NFS share to accomodate this until HP get the OST/Synthetic working.

Kev

[Kev_Lamb]

Ok, just to generalise, does anyone use NFS mounted systems as Advanced Disk and Synthetic Backups on any system???

[RLeon · Accepted solution]

this maybe a push from them to get DataProtector in the door (over my dead body)

They were trying to offer us the B6200 before it even started support running in OST mode. The idea was that VTL mode is the future, even better when paired with Data Protector instead of NetBackup.
... Still puts a smile on my face today.

When OST does synthetics, it's call Optimized Synthetics. It is more efficient than 'normal' Synthetics because the heavy duty work is done inside the storage without having to go through a media server. (Discussed in this thread.)

Perhaps that is why HP would rather you use OST (Optimized) Synthetics than the 'normal' Synthetics through NFS. Ironically, their B6200 OST mode doesn't currently support Optimized Synthetics.
According to the Nbu HCL, it supports "Opt_Dup" but not "Opt_Synth".

AdvancedDisk with NFS is supported, though I don't think many people do this because it is generally best to provide such a setup with a dedicated backup vlan/subnet, but more importantly, when using NFS based storage-units, backups and restores with GRT is not officially supported/endorsed by Symantec, even if it works.

Synthetic backups would work on NFS based storage-units as it should, but the network will be busy with data going back and forth between the B6200 and your media server when backups are being synthesized, which is not very efficient compared to OST's Optimized Synthetics, as mentioned earlier.

[Kev_Lamb]

Many thanks RLeon, at present we do not use GRT so the use of NFS for Synthetic Backups is Ok, so far all my testing for backuop and restore is Ok.

You are correct about the lack of support for Optomized Synthetics, aparently they are working on this....when this will be is anyones guess.

Short term it looks like it will meet the requirements and hopefully in the long term we will get the OptSyn support from HP.

[teiva-boy]

When using a Dedupe product for Synthetics, there is a reason HP or EMC, etc don't support it.  Performance.

On a synthetic backup, data is read off the device, and recompiled into a synthetic full.  This read operation, and depending on the backup application can just hammer a dedupe appliance into being useless.  Too many open connections, too many open files, CPU maxed out, etc.  It's the rehydration of images that has to occur that is taxing it.

On an Optimized Synthetic, the backup application has a "hook," into the appliance to rather than manipulate and read back the actual image files; it will talk to the metabase/database on the appliance and just move pointers around in the database.  Never having to do the file open/read operations.  Never having to rehydrate data.  This takes both vendors to work together to make it happen.

So while as a Advanced disk it's working fine today.  At scale you could run into issues, which is why HP pushed back as a CYA.  But I also don't doubt the ulterior motive of selling the craptastic HP DP.