Performance question - Best processor option for MediaAgents

In my experience media agents typically are not processor bound. Memory size  and Disk Speed are much more important.

there is a sizing calculator out there on maintenance advantage that is actually pretty good. 

Your high CPU usage can also be the result of disk IO latency due to IO-wait. So have you checked the latency on the disk carrying the DDB? Also take notice of the following KB article: https://kb.commvault.com/article/SYN0003

All-in-all interesting question: curious what the outcome is going to be.

Hi Sergio,

XL Media Agent with 16 CPU with 64 RAM is good enough to handle 100 TB’s of DB data.

My suggestion to have a check on the DDB disks. If it is a physical MA’s, it is highly recommended that DDB disks should be an inbuilt SSD disk. SSD from shared storage mapped to MA’s will also cause issues on the later stages. 

Thanks
 

@Sergio V - curious on the frequency of the synthetic full backups - why every two days for that big database?

Hi All,

Thanks for the answers. Some more info:

• Sizing was calculated using commvault’s calculator (actually, Commvault engineers helped with it).
• DDB disks are internal SSD drives (RAID1). Usage is about 100MB/s while synthetic fulls are running (a lot less than what the SSD drives support). I will check latency tomorrow (when the next synthetic full runs).
• About the backup frequency - I just rechecked and it’s only thursdays and sundays for the 100TB BD. However, the customer wants to run them every other day eventually (or everyday if possible). It’s because they want to have full backups ready for restore as soon as possible, without having to wait for commvault to integrate the last full and incrementals in the restore window itself.

I’ll make sure to use better SSDs for our new MediaAgents. Still need to figure out what the processor configuration should be (stick with 16cores per MA? go with more cores? single-processor or dual-processor?)

Regards,

Sergio

Have you considered differential backups in addition to your schedule rather than adding more fulls on a DB that large?

You have to realize that there are physical limits imposed by every link in the chain from network to storage.

In other words do you even have enough bandwidth to move 100TB of data in a reasonable time?

Keep in mind that many of the speed measurements are synthetic in the sense that it is based on the calculation of data processed rather than actual data moved.

That said you should start with a deep analysis of what your underlying storage is doing, as once again the pressure is almost always on storage for things like backups and aux copies. 

The operations that I have seen that bring a media agents processor to its knees involve encryption.

You might also want to post what processes are taking up the most CPU under load.

I’ll be honest I barely read the initial post as CPU bound media agent operations are just not something I have seen.