Last week there was an interesting thread about the preferred strategy for the creation of policies on the Auburn NetBackup list. You can read the thread yourself at the Auburn list archives. If you aren’t familiar with this email list, it is an email list hosted by Auburn University. You can join the list or view and search the archives here. The list is strictly a peer to peer forum for NetBackup administrators. Occasionally you’ll see a Symantec employee respond to a question, but in general it’s a peer forum. Even if we don’t respond ourselves, you can guarantee we read it on a regular basis.
There are a number of people who always prefer to create one policy per client. One proponent is Curtis Preston, the author of “Backup and Recovery”. You can read Curtis’ explanation for one client per policy on his blog, "Mr Backup".
I was interested in the policy creation strategy thread, so I created a short survey and posted a link to a survey on the NetBackup Auburn mailing list.
Here are the results from the survey.
Participants: I invited all readers of the Auburn veritas-bu list to participate. I chose to allow only one respondent per IP address although did not gather or retain the IP addresses. Twenty-nine people participated. Here are the results.
- What versions of NetBackup do you administer?
I know that there are customers using very old versions of NetBackup, but I was a little surprised to see as many votes for 3.x versions. It seems that 5.1 and 6.0 are still the most commonly employed versions of NetBackup.
When asked about the whether you preferred one client per policy I got the following results.
- Always – 17.2%
- Sometimes – 62.1%
- Often – 10.3%
- Never – 10.3%
Note: In retrospect I should have better differentiated between “Sometimes” and “Often”. Since the choices were ordered right to left from “Always” to “Never” I expect people interpreted “Sometimes” to mean more frequently than “Often”. (Next time, I’ll write a more precise question, I promise)
The point for me is it that only 10% of NetBackup administrators who responded to the survey avoid putting only one client in a policy. In addition I believe that almost 80% of respondents often have a reason to put one client in a policy.
When asked why the policy creation strategy was employed 70% responded that it made reporting simpler. In addition, 53% indicated that one client per policy allowed for more scheduling flexibility. Only 30% indicated that they chose their strategy based on peer or consultant advice. One administrator commented that one client per policy made it easier to train new NetBackup administrators. That makes complete sense in that there may be historical reasons for certain policy groupings that might get lost over time. Trying to train a new employee might be more difficult in that circumstance.
For the total number of policies on the largest NBU server I got the following results. The number of policies ranged between 28 and 7000, the average number of policies was 487. I ran a quick analysis and determined that for this sample set, 85% of respondents administer systems with between 121 and 853 policies.
So what will I be doing with this information? I’m passing it along to the engineers responsible for the next generation Policy Execution Manager – i.e. PEM2. The same information will get passed to our large scale system test engineers who work hard to create internal environments that mimic customer settings.
In my final analysis, I believe administrators may be choosing “one client per policy” as a simple work-a-round for certain behaviors in NetBackup. Personally, I believe we can probably find better ways for you to be able to get your job done, without forcing you to manager 7000 policies for 7000 clients. Luckily, we’re already working on making NetBackup easier to configure and administer so we are already putting thought and effort into related areas.
If you are looking for a final recommendation on this topic I’m going to punt -- it works both ways and there are tradeoffs with both approaches so chose the one that makes sense for you.
Message Edited by Turlas on 04-15-2008 10:48 AM