Hello,
In one location i have two MAs(media agents) with local storage, each MA has:
1. SSD storage for DDB (two disks in RAID1 array), single logical disk
2. HDD storage for library (multiple disks in RAID6 array), single logical disk
So, I have two options:
A. Create two Deduplication storage pools, one per server and manage how agents are spread between those pools manually. With this approach I'm familiar on practice, it is not very convenient to mage such setup. But i clearly understand how jobs and clients are spread between MAs and what happens if one of servers will fail.
B. Create one big Storage pool with both MAs in grid, library paths will be shared between MAs using DataServerIP transport in read mode, pool will have common DDB with two partitions(one per MA). I'm not familiar with such setup and don't know potential downsides.
So, questions regarding option (B):
1. How agents and jobs are spread between MAs? How Commvault makes decision which local storage path to use, on MA1 or MA2? How it decides which DDB partition to use for particular agent or job?
2. What happens if one of MAs not available for short time? Is Restore possible for at least part of agents? Will backup jobs continue to work?
3. What happens if one of MAs is completely lost or not available long time?
And general question, which option A or B is recommended by Commvault?
Thank you in advance!
hello
When you have a single storage pool with both MAs in a grid, Commvault load-balancing mechanism to determine which MA to use for specific jobs. You can find more details about this process here
https://documentation.commvault.com/2022e/expert/load_balancing_operations_between_libraries.html
Regarding the decision on which local storage path to use (MA1 or MA2), if you have enabled "Select mount path for MediaAgent according to the preferred setting," the system evaluates the available storage paths and selects the optimal one based on factors such as load, availability, and path latency. More information can be found here
https://documentation.metallic.io/2024/expert/library_properties_mount_paths.html
As for MA availability, since you mentioned that library paths will be shared between MAs, configuring GridStor Alternate Data Paths is the best approach in this scenario. You can learn more about this configuration here
If one of the MAs is completely lost or unavailable for an extended period, and you have configured the settings mentioned above, you will still be able to perform restore operations using the available MA.
Best Regards,
Mohamed Ramadan
Data Protection Specialist
Personally, because they’re local storage, I would lean to option A.
With local storage you cannot access the data if the MA is unavailable. If you have a single Storage Pool to load balance jobs across the MAs, losing either of the MAs means potentially losing access to most of the jobs.
I would go with option B if you were using SAN or NAS. These storage types would still allow access to the storage from any MA, should your primary MA go down.
My $0.02
Thanks,
Scott
Hin AndresL, all,
I agree with Scott here because if one of the MAs goes down, the local storage will be gone with it, no matter what you configure in Mount Path Sharing and GridStor. And even worse: With Deduplication you will probably not be able to restore or copy backups using the other MediaAgent on its own as the unique blocks belonging to a backup job are most probably scattered across both mount paths. The chance is actually quite low to have all unique blocks of a specific job on the same Mount Path.
Regards,
Markus
Reply
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.