Can some one please let me know what does exactly the below command will do

Install-CSDatabase -CentralManagementDatabase -SqlServerFqdn BackendServername -SqlInstanceName Default

Does this command will refresh the existing back end database updates and access levels as per the lync settings, will it also try to make the RTC database to Restricted User.

Anil,

this command will either install new Central Management Database, or apply database updates when a cumulative update requires it (note, database name is XDS not RTC).

As part of the upgrade procedure, user mode is set to restricted, then update SP are applied, then user mode is set back to multi-user.

For reference check this article: http://www.mylynclab.com/2013/06/installing-lync-2013-cumulative-updates.html

particularly:

State of database xds is DbState_RequiresMinorUpgrade.
Database xds set to mode Restricted.
Dropping all procedures, functions and views from database xds.
Executing Xds.sql...
Adding master role...
Setting database state to active...
Setting owner for database xds to sa.
Creating login DOMAIN\RTCUniversalConfigReplicator.
Creating user DOMAIN\RTCUniversalConfigReplicator.
Creating Schema DOMAIN\RTCUniversalConfigReplicator.
Creating login DOMAIN\RTCUniversalReadOnlyAdmins.
Creating user DOMAIN\RTCUniversalReadOnlyAdmins.
Creating Schema DOMAIN\RTCUniversalReadOnlyAdmins.
Creating login DOMAIN\RTCUniversalServerAdmins.
Creating user DOMAIN\RTCUniversalServerAdmins.
Creating Schema DOMAIN\RTCUniversalServerAdmins.
Adding account DOMAIN\RTCUniversalReadOnlyAdmins to role ConsumerRole.
Adding account DOMAIN\RTCUniversalConfigReplicator to role ReplicatorRole.
Adding account DOMAIN\RTCUniversalServerAdmins to role PublisherRole.
Setting database version: Schema Version 10, Sproc Version 13, Update Version 2.
Setting the database xds to multi user mode.
Database xds is set to multi user mode.

note how database is first set:

Database xds set to mode Restricted.

then:

Database xds is set to multi user mode.

for full cmdlet reference please check http://technet.microsoft.com/en-us/library/gg399044.aspx

hope this helps.

Hi Alessio,

I have gone through the blog, just want to confirm by executing the below command won't touch the RTC database, because we are mentioning the SqlInstanceName as Default ?

Install-CSDatabase -CentralManagementDatabase -SqlServerFqdn BackendServername -SqlInstanceName Default

Hi - CMS instance is "RTC" by default, double-check before executing.

Also, would be good if you elaborate on why you want to run this command and what's your concern.

regards.

Recently we encountered an issue in Lync..All lync clients received an error "Limited functionality due to outage"

All the users are unable to see contact lists and unable to access Lync functionality apart from IM. All  users are unable to see contact lists and unable to access Lync functionality apart from IM.

We noticed that the user persistent database (RTC) becomes unavailable to access and threw the below error message. 

The database rtc is not accessible. (ObjectExplorer)

We ran the below command to refresh the existing back end data base updates and Access levels:

We checked the behaviour post this command ran successfully and noticed that the access level changed as (Single user) for the RTC database.

We were trying to change the access level to (Restricted user) but the operation got stuck in the deadlock.

Followed below steps to clear the deadlock:

Stopped all lync services using command (Stop-CsWindowService) on following front end servers

Exec sp_who2

'alter database rtcdyn set restricted_user with rollback immediate' to change the RTC from single user mode to restricted user mode

Started all lync services on front end servers

Raised a case with MS for RCA for RTC database going inaccessible