When taking into account different backup solutions which are in the market, MS DPM 2010 was rather attractive for us. It’s a solution from leading software vendor and it’s cheap. However, DPM has a number of limitations which forced us to abandon it and rebuild our backup procedures from ground up. Here I’d like to describe major points as impartial as I can.
The first thing about DPM is that it uses VSS snapshots as one and only backup method. The major consequence is that you are very limited in flexibility and cannot do incremental, differential or full backups, implement GFS backup strategy or Progressive Paradigm. The only option you have is to exclude weekends or any other particular days from backups. That means ineffective storage utilization and inability to have longer data retention as you could have with flexible backup policy as GFS for instance, not to mention additional spendings on storage.
Another problem of VSS is that it supports only 64 snapshots. Basically, that means if you exclude weekends from your backup policy, you will be able to have backups for 89 day period. It’s clearly not enough if, for example, you work in a financial institution where you have strict policies of long data retention. DPM assumes that you will use tapes for prolonged data retention. If you already have tapes then you are good to go, if not then once again it’s additional expenditures.
Interestingly enough in DPM you cannot have different retention policies for data which resides on the same volume. Say I want to keep database backups for 3 months and transaction logs for the last week. If database backups and transaction logs reside on the same volume then you will have to create the second volume and separate them.
Limitation which I personally find very inconvenient is space reservation. Each time you create a Protection Group you reserve space for it. Say 500GB. And you cannot change it. In case one folder from ten, which you backup from the server, moves to another place and 250GB become free, the only option you have is to destroy Protection Group, loose all backups and recreate it. DPM helps you in situation when you don’t know how your data will grow and you can specify smaller storage size initially and it will automatically grow as needed. However, it can extend only 32 times. If you hit that limit, then you are in the same situation as before.
Another major issue arise when you change protected server name. If server name is changed the only option you have is destroying protection group, loosing all backups and recreating it.
The next limitation I also find inflexible is target storage. In DPM you can only use blocked devices as target storage to keep your backups. So it’s either DAS, FC or iSCSI storage. NAS is not supported.
If you work in SMB then you would probably have issues with installation and support of legacy systems. DPM works only on 64-bit Windows Server 2008 platforms (Windows Server 2003 is not supported). DPM doesn’t support Bare Metal Recovery (BMR) of Windows Server 2003.
And lastly, DPM keeps all data on a raw volume. Raw volumes are more efficient in terms of disk I/O performance. But when it’s helpful for DBMS it doesn’t seem to make any difference for backup software. The downside of it is higher risk of loosing all data in case of volume damage or DPM bug. It’s arguable, so I will leave it as my personal opinion.
In conclusion, it’s rather disappointing to see how software with 7 years history (DPM 2006 was released in 2005) has more limitations than any backup software solution I can think of. Even if you don’t have enough money for Symantec Backup Exec, ARCServe Backup, HP Data Protector or any other software, I would recommend to make more effort and search for some other solution. Otherwise you can fall into the same trap as we did.
Tags: backup, Backup Exec, Bare Metal Recovery, BRM, data protection manager, Data Protector, DPM, inflexibility, limitations, Microsoft, MS, policy, restore, retention, schedule
Niktips's Blog 
March 10, 2012 at 5:34 pm |
Interesting impressions, most of which are relevant to SMB’s as well. The raw volume storage creeped me out a little too, as did the no nas, no usb.
I did like the speed with the block level backups for full system images, they are way faster than backup exec. I can do a domain controller in 14 minutes, vs 1+ hours for Backup exec.
But you raise a number of interesting points. Thanks for the article.
March 11, 2012 at 2:55 am |
I tried that to be more of facts than impressions. I’m glad it was helpful for you.
December 11, 2012 at 4:55 pm |
Hi,
About 64 snapshots, do you know if there is the same limitation on DPM 2012? It looks like very strange that Ms propose a backup solution with a retention limit of 3 months..
Thanks,
December 12, 2012 at 11:06 am |
Haven’t used it ever since. You can try it out though.
August 21, 2013 at 11:55 am |
yes the same limitation exists in DPM 2012 SP1
January 3, 2013 at 3:28 pm |
Your article is really excellent. I hope other people will see this before their DPM deployment. I am also facing many limitations for disk and tape. There is no differential or incremental tape backup in DPM. DPM is really disappointing.
April 25, 2013 at 8:24 pm |
You raise some valid points, but there are ways to work around the limitations. For us, compared to Backup Exec, it was a better solution.
We have been using DPM for about a year now. We did know about the limitation but have been pretty happy with it. You can’t do “incremental”, but the express backups do not take very long at all. Where a full backup with Backup Exec over the weekend was talking over 24 hours (incremental during the week) we can now don’t have to worry about it. We backup throughout the day with little performance issue. SQL gets backed up 4 times a day, file servers once, Exchange 3, etc… We save about 6 days on disk and send tapes out once a week.
I created my own storage using eSATA and port multipliers, so a single eSATA cable can carry 5 drives. It was pretty inexpensive and performance is incredible. We are a non-profit so we use all MS, because they are incredible to non-profits. So that made it much easier for us.
My biggest complaint is it cannot backup my CIFS storage from my iscsi storage. I can do snapshots on the SAN, but DPM can’t use them. The odd thing is Windows can use the snapshots (i.e. previous versions).
April 26, 2013 at 1:14 pm |
I didn’t say that you can’t workaround them. And I’m sure that some customers are even OK with all the limitations. But I feel like it’s better to have something that’s working good, than to run into issues here and there and try to workaround them.
June 16, 2014 at 8:28 am |
One more limitation – very important for us – is that you cannot define patterns for including or excluding certain resources. Any decent backup solution does permit you to create filter with wildcards. But not DPM. If you don’t want to backup Temporary Internet Files of your users, tough luck, you have to ‘unclick’ every
single one of them.
Managing space is a great PITA – there is no sane way to move the volumes around (no, the Migratesomethingsomething.ps1 script is not sane – more often than not it creates a copy of the volume while leaving the old one behind).
And the last and most serious flaw – debugging this beast is close to impossible. Especially considering the way DPM works and how windows logging works. The relevant logs are virtualy non-existent. (no, “Backup failed” is not enough, neither is non-googleable 0x800somethingsomething error code).
June 16, 2014 at 8:39 am |
It’s an old post, but it doesn’t seem that DPM is getting any better than it was a few years ago. Thanks for the update.
August 7, 2014 at 11:44 pm |
The list can go on and on!
No long term storage option unless you use tapes. There is a work around by using virtual tape software but this is very messy and an extra cost.
Having to manually erase expired tapes.
Reporting is terrible. Unable to produce a simple report stating which backups have failed and the reason why.
Must use backup to disk for short term storage for Exchange or else you cannot backup Exchange databases in a DAG.
No deduplication.
Limited backward compatibility. ie current version DPM 2012 R2 cannot backup Server 2003, SQL 2005, Hyper v Server 2008.
August 8, 2014 at 2:23 am |
I can feel your sorrow, Charlie. I really wish you wouldn’t have had to go through all this pain and misery. But unfortunately that’s the reality of DPM.
August 11, 2014 at 10:28 pm |
Folks, you need to read up some more on DPM. First, Secondary DPM servers are what you use to get long-term backups. So you’d have 64 snapshots on the first DPM server, which I usually do twice a work day for 45 days. Then the secondary DPM server backs up the first one, so 64 snapshots could be once a week for 64 weeks, or once a month for 64 months.
MS added back in support for backing up Windows Server 2003 with DPM 2012 R2, although you could previously still do it by using an older agent.
The point has to be made that if you are continuing to keep around ancient products, then why would you upgrade to the newest DPM? Just continue running 2012 w/SP1 or 2010 and use it to back up your older environments as needed.
Deduplication is now supported if your file server is using it, so backing up a deduped volume means it stays deduped in DPM.
For sure you will want to use the central console feature, which is basically operations manager, for centralized logging and monitoring.
As for moving stuff around, I switched all my DPM servers to VMs years ago and never looked back. They all run on top of vSphere and PowerVault storage, and I keep the DPM server count high so each VM can be moved in a reasonable amount of time (less than a week) if the need were to arise.
August 17, 2014 at 1:53 am |
Hi j.rod, thanks for the valuable hints and tips. I published this post two years ago and hasn’t worked with DPM ever since. So I can’t participate in this discussion in any sensible way. This post now lives on its own.
It sounds a bit odd to me to backup a backup server. But I’m glad to hear that you’ve had positive experience with DPM and it might be not as bad as it looks at first glance.
August 17, 2014 at 9:48 am |
Hi j.rod
Yes the recently released update now supports 2003, I can confirm that the older agent would not allow you to. It was due the large number of requests\complaints that forced MS to add 2003 support.
I take your point about using a secondary server but this is double the hardware and OS licences. Which is crazy.
Using native dedup on a server can only take place for example a files server D drive. You won’t be enabling dedup on a OS volume, databases etc so you won’t get the full benefit. Dedup isn’t supported on VHD or VHDX files. Dedupe data can’t be backed up to a secondary server.
It is important to list these limitations should companies be searching for an appropriate backup solution.
September 8, 2014 at 1:38 pm |
2012 and 2012R2 do not suppport encryption and compression on ntfs – classic.
October 1, 2014 at 1:59 pm |
I understand some of your issues, but in reality, we moved from Backup Exec which rarely worked properly – even if it claimed success, often that wasn’t the case to DPM.
Since then, we’ve had very few issues – backing up a considerable number of Physical and Virtual Servers, various workloads and DPM is the best thing since sliced bread.
I don’t think the cost of drives and storage is that big a deal – increasingly so since storage costs fall rapidly – and there’s no real harm in using lower grade drives for this type of application).
One point from your original article though:
“Interestingly enough in DPM you cannot have different retention policies for data which resides on the same volume. Say I want to keep database backups for 3 months and transaction logs for the last week. If database backups and transaction logs reside on the same volume then you will have to create the second volume and separate them.”
In your example, I suspect the answer from MS (and indeed me) is that you’re doing it wrong – you should not be storing Database and Transaction Data on the same disk set (volume). For MS SQL at the very least, it’s recommended you have software, data and transactions on different volumes. If you follow that, it is a non issue to begin with.
While of course everyone has a different scenario, we use DPM to backup several physical sites, a lot of servers, lots of workloads, and use the primary/secondary DPM server & site functionality and it works. All day, every day. I can restore back whenever I want, and it never fails us – it is as good as it claims.
June 12, 2015 at 4:33 pm |
Hi Vince, when you said you use DPM server to backup lot of servers, how many servers were you referring to and were they all virtual servers in a MS environment?
July 10, 2015 at 1:42 pm |
Can DPM integrate with unified VNX 5400?
August 18, 2015 at 2:00 pm |
Unsure about VNX as I can’t find any hardware support matrix however take a look at the following, especially around supported file system ie NTFS only and no NAS support. You will need a tape library or virtual tape library software if you wish to enable long term storage or use a second DPM server, good luck! https://technet.microsoft.com/en-us/library/dn554221.aspx
November 18, 2015 at 4:43 pm |
Adding to the conversation. we’re just beginning to use DPM2012R2. We’re currently backing up two cloud environments, about 20 servers in each, varying loads, 15min increments for 30 days getting two recovery points per day. Our DPM server is a Gen2 Hyper-V Server with the data drive on a volume that is being dedupped. We’re getting about a 70% dedup ratio. Our volume is large enough for multiple DPM servers so far both DPM servers are benefiting from the Dedup. Since our images are nearly the same the storage savings is pretty awesome. So far we’re into our 1st month of running DPM. Previous BU app was Appassure same compression ration but each core server required it’s own dedup database. Memory requirements are much lower than expected. Appassure requires 8gb minimum to run correctly under load. DPM is currently running at 4gb for the same load. All of our servers being backed up are 2012R2. Working good so far just wanted to add 2 cents to the topic.