Backing up to NAS

[Bruce123]

We are planning to replace our current backup system(s) with something more suitable.

 

At the moment we use a combination of BExec 9 (dates back to 2003), Windows 2003 backup, Windows 2008 backup, robocopy and a script. For media we use 1TB and 320GB USB HDDs. Most of our backups are differentials (full at weekend) and we have 5 Friday drives.

 

Backup USB HDDs are transferred each day to a fire proof safe located at a different site. But can sometimes cause problems, especially during holiday periods.

 

We have 4 sites and the connections between these sites have recently been upgraded to 100Mbit (from 2Mbit).

 

The opens the potential for backing up over these links to NAS. But I my knowledge of backing up to NAS is very limited. I have looked at a QNAP unit which has 6 SATA bays (up to 6TB). One option is to use two of these, where 3 sites backup to a NAS at the 4th site, and the 4th site (where most of the data is located) backup up to a second NAS at one of the other 3 sites.

 

My main concerns are:

 

1. Whether we have sufficient bandwidth to backup the data over the links.
    
   
2. The whole concept of backing up to online storage. Potential for hacker to delete the backups (although we could do regular transfers to USB HDDs for archive). How is this viewed or addressed? What is accepted practice.
    
   
3. The most appropriate backup software (looking at Microsoft DPM 2010), but feedback I have seen suggests it is far from perfect and can be difficult to setup.
    
   
4. I would prefere BExec 12, but we have 34 servers (although around 7 are due to be decommisioned soon), but that still leaves 27, and at £300 agent lisence per year, it would be very costly.
   

 

Any advice from anyone in the educational sector (or otherwise), would be much appreciated.

 

Many Thanks,

 

Bruce.

 

Leeds, UK.

Edited October 3, 2010 by Bruce123

[timbo343]

how much data are you backing up?

[Bruce123]

The main site has around 600GB (including the virtual HDDs on the Hyper V host).

 

The other 3 have around 200GB at each.

 

Total 1.2TB.

[AngryTechnician]

I currently back up to an iSCSI NAS using a combination of DPM 2010 and Windows Server Backup. Although I am currently doing this over a 1Gb connection to the opposite side of our (large) site, it was on a 100Mb line at one point and worked just fine.

 

If your intersite links are resilient and actually gives you 100Mb, I don't think you'll have a problem, especially if you are able to prioritise traffic on your network and schedule the heaviest parts of the backup out of hours. I've had very few problems with DPM, and it not only has bandwidth throttling built-in but transfers changes to the backed-up data throughout the day (every 15 minutes by default). The systems that use WSB are scheduled for out of hours. The amount of data I'm transferring is around the same as yours, though in my case it's all from the main server room rather than split up.

[Bruce123]

Thank it's reassuring that you use DPM 2010 to backup to a NAS over a network and it works satisfactorily.

 

The throughput of each WAN link is around 40-50Mbit (measured by transfering a file), which doesn't compare too badly with FastEthernet where I guess you'd expect to get around 70Mbit. The central site is connected at 300Mbit, which allows the other 3 sites to connect in at 100Mbit at the same time, without a bottlekneck. As far as I know, the WAN links aren't resilient to the extent of having a failover link.

 

The NAS I'm looking at has iSCSI and the salesman (at CCL) suggested that this geatire could be useful for backups and I believe that it also has USB connections to allow a simple backup from NAS to USB HDD. I am thinking that setting up RAID5 on the NAS will improve performance and fault tolerance, as I doubt we will need the full 6TB. But I don't know how far you'd be able to go back for restores.

 

As regards to prioriting traffic (lowering it for backups), I could do that on the router using the IP addresses of the NASes and lowering the priority on packet with this source/destination addresses. But i'd still be concerned about DPM using precious bandwidth on our new WAN links, for backups during the day. Can DPM not be configured to do backups out of hours?

 

How easy did you find DPM 2010 to setup? I just wonder if we need to pay for assistance to help us set it up, but I wouldn't want us to pay for consultancy unless it is absolutely necessary.

 

I think I may also need to up the number of server backup / enterprise licenses from what I orginally estimated (more SQL server installs than I realised),

 

Thanks,

 

Bruce.

Edited October 3, 2010 by Bruce123

[AngryTechnician]

As far as I know, the WAN links aren't resilient to the extent of having a failover link.

Poor choice of word from me; when I said resilient, I really should have just said reliable, i.e. doesn't go down that often. iSCSI can cope with links dropping, I just wouldn't want it happening daily.

 

Setting up DPM wasn't a technical challenge for me. Compared with other System Center products I've used (SCCM, SCE), it was actually quite easy. Obviously I don't know your level of technical expertise, but you seem like you are knowledgeable enough to manage it without consultancy. Do you have an onsite Exchange or SharePoint? I found it easier to set up than either of those...

 

Definitely use RAID5 on the NAS; yes it's only a backup, but if your backup gets toasted due to a disk failure and the very next day the Head wants some files he deleted back, you'll really wish your backup wasn't toasted.

 

I would be surprised if you find the incremental data transfer during the day to be a problem. I will take a better look tomorrow, but I'm pretty sure the bandwidth usage is actually quite light, plus you can always throttle it. Here's what the throttling settings look like so you see what sort of flexibility you have to work with:

 

 

These settings are per-computer, so you can set different throttling on different servers.

 

On the subject of licensing, consider whether you actually need the DPM feature set for all those servers. As I said, I use a combination of DPM and WSB. Specifically, I use WSB on the servers where all I'm really interested in is disaster recovery, i.e. the server went pop and I want it back to how it was last night. WSB works just fine to an iSCSI device, so I use the same NAS for both backup types. DPM is used where I frequently want to restore of specific files or SQL server data, or can't afford to lose a whole day's data.