Remove mailbox database copy from DAG

Question

Hi There,
We would like to remove the mailbox database copy from our exchange server as we are lack of the space on our fixed vhd and we hope to be able to free about 100GB from the passive database copies as we have deployed DAG. is there any guidelines or procedures
to safely remove the database copies? currently, we have 4 mailbox servers, HQMB01, HQMB02, SSMB01, and SSMB02. HQMB01 and HQMB02 is already part of DAG members by itself. however, on ssmb01 and ssmb02, we also add in HQMB01 and HQMB02 as the DAG member,
thus they can fail over to HQMB01 or HQMB02 if their server have issue. in this situation, SSMB01 and SSMB02 passive copies is also inside our HQMB01 and HQMB02. As the our HQMB01 and HQMB02 is lack of the disk space and we would like to remove SSMB01
and SSMB02 from the DAG, thus we could remove the passive database copies. The following is the picture of the activation preference for all servers. what is the procedures and the guidelines to remove mailbox database copy and also remove the server from
the DAG members? we are quite confuse and worry that after we are removing wrongly and cause the active database to lost as we understand that there is replication happening between them. as we have 4 mailbox servers from which server we should perform
the task? Wish to get some advises from the exchange guru from this forum. we are on exchange server 2010 sp1 and windows server 2008 R2.Thanks so much.
Name                 : HQDB01
Servers              : {HQMB01, HQMB02}
ActivationPreference : {[HQMB01, 1], [HQMB02, 2]}
ReplayLagTimes       : {[HQMB01, 00:00:00], [HQMB02, 00:00:00]}
TruncationLagTimes   : {[HQMB01, 00:00:00], [HQMB02, 00:00:00]}
Name                 : HQDB02
Servers              : {HQMB02, HQMB01}
ActivationPreference : {[HQMB02, 1], [HQMB01, 2]}
ReplayLagTimes       : {[HQMB02, 00:00:00], [HQMB01, 00:00:00]}
TruncationLagTimes   : {[HQMB02, 00:00:00], [HQMB01, 00:00:00]}
Name                 : SSDB01
Servers              : {SSMB01, SSMB02, HQMB01, HQMB02}
ActivationPreference : {[SSMB01, 1], [SSMB02, 2], [HQMB01, 3], [HQMB02, 4]}
ReplayLagTimes       : {[SSMB01, 00:00:00], [SSMB02, 00:00:00], [HQMB01, 00:00:00], [HQMB02, 00:00:00]}
TruncationLagTimes   : {[SSMB01, 00:00:00], [SSMB02, 00:00:00], [HQMB01, 00:00:00], [HQMB02, 00:00:00]}
Name                 : SSDB02
Servers              : {SSMB02, SSMB01, HQMB01, HQMB02}
ActivationPreference : {[SSMB02, 1], [SSMB01, 2], [HQMB01, 3], [HQMB02, 4]}
ReplayLagTimes       : {[SSMB02, 00:00:00], [SSMB01, 00:00:00], [HQMB01, 00:00:00], [HQMB02, 00:00:00]}
TruncationLagTimes   : {[SSMB02, 00:00:00], [SSMB01, 00:00:00], [HQMB01, 00:00:00], [HQMB02, 00:00:00]}

Answer 1

Hi Exchange Guru,
thanks so much for the prompt response..i have few queries to ask following your guidelines above:
1. from the show result above, I am still confuse which server that I should go to remove as this is involving 4 database copies. from what I understand from the truncation or replay lag times of SSDB01 and SSDB02, I can see that HQMB01 and HQMB02 are on
the third and fourth preference, which means that SSDB01 and SSDB02 will be able to failover to each of them when there is a failure and it cause the passive copies of both of SSDB01 and SSDB02 to be stored in the HQMB01 and HQMB02. what my purpose
is to remove both SSDB01 and SSDB02 passive copies in HQMB01 and HQMB02. in this case, should I login to SSDB01 or SSDB02 mailbox servers to perform the removal with your guidelines above?
2. is the command as below:
Remove-MailboxDatabaseCopy -Identity SSDB01\HQMB01 -Confirm:$False
Remove-MailboxDatabaseCopy -Identity SSDB01HQMB02 -Confirm:$False
Remove-MailboxDatabaseCopy -Identity SSDB02\HQMB01 -Confirm:$False
Remove-MailboxDatabaseCopy -Identity SSDB02\HQMB02 -Confirm:$False 
will this cause the risk either of my HQDB01, HQDB02, SSDB01, and SSDB02 active copies accidentally  being removed? I am sorry that I am a bit naggy and always want a confirmation as this is very critical and I must be super careful.
3. If after the removal successful, when is the best time to go to the drive where the passive copies stored and remove them so I can clear some space on  my disk? and is it just as simple by going to the drive and do a folder file deletion manually?
because I just worry when I delete the file and the server is still replicating between each other, which will cause even corruption to the active database.
4. From point 3, you mention about when the server is empty. what do you mean by that? do you mean that when the passive copies are no more there? and what command that I used to check?
5. From point 4, is removing the server from DAG the last step to be performed? yes, I want to remove them from DAG, thus will left only HQMB01 and HQMB02 as one DAG and SSMB01 and SSMB02 as one DAG.
Thank so so much for your patient and attention.
Regards,
Henry