With all the backup products in the market, how do you choose which product is suitable for any given requirement? Well for this post, I shall introduce you to EMC Avamar. Avamar technologies was aquired by EMC back in 2006 and provides efficiency in backup via deduplication at block level.
Avamar is predominantly positioned today as an appliance with the Avamar software pre-isntalled on a Dell Power Edge 2950. In the same fashion as any other backup products, agents are deployed on systems to be backed up.. nothing new there. The intelligence comes into play where deduplication is concerned. Avamar agents will keep track of blocks which have been backed up and only send changed blocks of data over the network. This has a few benefits:
- Capacity Efficiency (only change a word on a previously backed up document, you only backup the changed blocks.. not the whole document again.
- Network utilisation. End users become accustomed to the fact that their network will be hit hard during a backup window. With products like VMWare; server sprawl is rife and you can end up really hammering your network. With Avamar only backing up changed data, network utilisation during backups is dramatically reduced.
- Remote offices. Many Companies have remote offices dotted around with piddly little links, block level changes will be significantly smaller than file level incremental changes. So bandwidth issues aren’t allways as apparent with avamar.
- Avamar plays best with customer data that have large commonalities (ie, file data, OS library files, etc.). Less commonalities (ie, Database volumes, where rate of change is greater) will mean a lower dedupe ratio.
Avamar appliances can be sold as single nodes (in which case you need a replicated pair of single nodes for EMC to support the solution) or as a RAIN solution which works in much the same way that RAID does. You have a parity node, capacity nodes and a spare node.
If you come up with an avamar opportunity and want to have any level of accuracy in terms of the size of appliance required.
These are the questions the reseller needs to be asking.
- How much of the data is File data ?
- How much data is Database data ?
- Is any data VMFS (VMWare system) ?
- if so how much ? how much data is email data ?
- Is there any mail archive data, if so how much ?
for each of the above, what are the following :
- Number of daily backups being retained number of weekly backups being retained
- number of monthly backups being retained (would advise not to retain more than 3 months of data, is it becomes a very costly solution).
- What is the daily rate of change for each of the above (% Approx)
- What is the projected annual growth of data (% approx)
- How many sites are being backed up
- Data being backed up per site
- size of link between sites
Plus the obvious questions around how much they’re looking to spend, the smallest change in an avamar config can have potentially large cost implications.
See the below video for a more in-depth white board curtosy of EMC: