HOTSPOT
You have an Exchange Server 2013 organization that contains three servers named EX1, EX2, and EX3 in a
single Active Directory site. All of the servers are members of a database availability group (DAG) named
DAG1. Each server has a copy of all the mailbox databases.
You discover that the copies of a database named DB1 are in a FailedAndSuspended state due to disk failures
on EX2 and EX3.
You replace the disks.
You need to start seeding DB1 on EX2 from EX1. The solution must ensure that DB1 can be seeded on EX3
simultaneously.
What command should you run? To answer, select the appropriate options in the answer area.
Hot Area:
Answer: 
Explanation:
Use the Update-MailboxDatabaseCopy cmdlet to seed or reseed a mailbox database copy.
We reseed the database with a new copy by issuing the following command.
[PS] C:\\>Update-MailboxDatabaseCopy -Identity “DB1\\EX2”
For long reseeds where you do not want to leave your Exchange Management Shell open, or when scripting a
reseed and you don’t want the script to have to wait for the reseed to complete, you can use the -BeginSeed
parameter.
[PS] C:\\>Update-MailboxDatabaseCopy “-Identity “DB1\\EX2” -BeginSeed
The BeginSeed parameter is useful for scripting reseeds, because with this parameter, the task asynchronously
starts the seeding operation and then exits the cmdlet.
Incorrect:
* The MaximumSeedsInParallel parameter is used with the Server parameter to specify the maximum number
of parallel seeding operations that should occur across the specified server during a full server reseed
operation. The default value is 10.
Update-MailboxDatabaseCopy
https://technet.microsoft.com/en-us/library/dd335201(v=exchg.150).aspx