PST Import Rate - EVPM vs. Wizard

[Raffi_Makhoulia]

1- What is the difference in number of threads between a PST import using EVPM versus the Wizard?

2- Or is it that the EVPM version can import multiple PSTs at the same time while the Wizard imports one PST at a time from its given PST list?

[Michael_Bilsbor]

Hi,

At the end of the day both are the same back end and so same performance.
So if you use EVPM and multiple PSTs get migrated at the same time or if you run multiple instances of the wizard then you should see the same performance.

[TonySterling]

Is there still the recommended limit of 5 at once when using the wizard?

[Michael_Bilsbor]

Hi,

My understand is that really the root of the recommendation comes from how much CPU you might have available. So if you migrate 5 PSTs and have free CPU cycles then you could consider migrating another PST at the same time and so on.

[David_Messeng1]

We maxed out at 5 per CPU. Can't rememebr how fast the CPUs are mind but they hyperthreaded.

In live running we throttled back to 2 per hyperthread giving us 8 simultaneous PST migrations per server. 4 servers, running only at night gave us about 1,000 users a week.

Bottleneck is actually getting the PSTs onto the server's local disk rather than doing the imports.

Presume the wizard still runs in serial?

[Raffi_Makhoulia]

Gents, thanks for the responses. They are helpful. But, I would like to know, as I remember from previous information, that the EVPM version of the migration used to run with 4 or 5 threads by design without us doing anything. On the other hand, the wizard import works with a single thread one pst at a time and to migrate multiple PSTs we need to run multiple instances of the wizard. Is this correct?

[TonySterling · Accepted solution]

Raffi,
Yes the EVPM could be set to do 5 migrations at once by setting the following setting.

ConcurrentMigrations = 5

With this set, EVPM will spawn 5 migrator processes from a single initialization file.

This makes the set up and running of parallel processes simpler. The maximum value allowed currently is 5.

It is recommended that the number of parallel PST Migrator processes/threads is set at 5.

So they are both single threaded, by setting the ConcurrentMigrations or running multiple instances of the wizard you are able to get more throughput.