Forum Discussion

CadenL's avatar
CadenL
Level 6
4 years ago

Real world max number of media servers

Hi

I'm trying to understand the key factors when determining the number of media servers a Master server can cope with. This will be a new environment running NBU 8.3 and the master server is likely to be a new 5250 appliance.

Essentially there will be upwards of 100 remote sites with a small number of windows clients at each location - data size will be <500GB of file and SQL databases per site and I want to have a local media server on each site with a central master server.

This sounds a lot of medis servers - maybe too many - but I want to rule out the feasibility of having a media server per site before I look at alternative options  - but to rule this out I need to better understand the potential issues here.

Licensing isn't a concern, ISLs are all good, stable and >1GB/s, I'd calculate that each site will consist of about 10 backup policies and perhaps 30-40 backup jobs will run daily for each site.Backup strategy will be full at weekends and Incrementals during the week - but these can be staggered if necessary. I don't yet know the total number of files that will be protected each day - but I can get this info to calculate the size of the catalog etc.

I feel that the master server will be single point of failure for the entire environment and therefore accept this an a potential issue for this solution in the event of hardware failure of extended downtime for maintenance etc.

What else should  I consider, or is this solution completely viable and nothing to be concerned over :0)

kind regards and hope everyone has a good Christmas

Linux
  • pats_729's avatar
    pats_729
    Level 6
    4 years ago

    Hi

    Hope you having a nice chrismas holidays.

    For your requirement i recommend you review NetBackup Planning and Performance Tuning guide. Here is attached a small snip of table showing how many media servers a Master should have.

    However, there are many aspects well explained with real time calculations in this guide.

    https://www.veritas.com/bin/support/docRepoServlet?bookId=99904379-99904385-1&requestType=pdf

    Irrespective of NetBackup version this guide is still valid.

     

    • CadenL's avatar
      CadenL
      Level 6
      4 years ago

      Hi

      Many thanks for the information - that guide will give me everything I need :0)

      I did note though, that 8.3 has a different set of recommendations - in as much exceeding 50 media servers isn't recommended and that the master server would need close to 256GB of RAM. So I think that I need to split this requirement into multiple master server domains.

      thanks again

      • davidmoline's avatar
        davidmoline
        Level 6
        4 years ago

        Hi CadenL 

        I think you might be referring to the new NetBackup Perfomance Tuning Guide for 8.3/8.3.0.1/9.0.

        And yes the RAM requirement for the master does seem high. This has been raised internally to check as some in the SE community also thinks it is high. I'll provide an update when I know more.

        David 

  • jnardello's avatar
    jnardello
    Moderator
    4 years ago
    I think the max Media Servers on a single Master I've ever done was around 80 (mostly SAN Media Servers), and although that was many years ago I think the biggest pain point then is still going to be the same now - the administrative overhead of hooking everything to one Master. As you said, you're willing to accept the single-point-of-failure of running with one Master, but please (re)consider : how often do you need to cycle the NBU daemons on the Master ? How often does the Master's OS get patched and/or rebooted ? How long does it take you to upgrade NBU itself on that Master ? If a bathroom located above the Master's DC suddenly floods and leaks into the DC's PDUs, how long will it take to recover the Master to a different site & resume backups for all of those remote sites (troubleshooting IP & NBU security cert issues for 100 Media Servers simultaneously sure sounds like fun to me!) ? If one of those sites loses its network link because of a construction worker cutting into the wrong pipe and hence the Master is unable to talk with some of its Media Servers for a period of time, are you okay with the increased delays everything else is going to start seeing (lots of name lookups in NBU after all, timeouts in catalog cleaning because it can't talk to that box to expire MSDP images, etc. ). Can every one of those remote sites handle identical (long) downtime or will you start losing database servers because they can't offload their transaction log files in a timely fashion ? Do some of those sites have business-critical data that according to SLA MUST be offsite within x hours "or else" ? I would highly recommend spawning another Master or two and breaking up your Media Server load logically between the Masters somehow, particularly if licensing isn't an issue. Best of luck !
    • CadenL's avatar
      CadenL
      Level 6
      4 years ago

      Hi

      Many thanks for your thoughts and it's good to get feedback from someone who has experience in large numbers of media servers. I take on-board all your thoughts and comments and will absolutely reconsider the solution following your feedback.

      thanks again