Moving Site Collections between Content DBs

Question

I have a very huge Content DB with over 500+ site collections. I want to split it into many databases that I can done using Powershell. I have two questions:

1. Whats will happens to users working during the Site collection move process? will they get locked out OR get errors etc?

2. How long time the move will take? i want to know if there is some powershell method/command to know the exact move time. for example how long it will take to move one GB data per minute?

Answer 1

1 - The Move-SPSite cmdlet moves the data in the specified site collection from its current content database to the content database specified by the DestinationDatabase parameter. A no-access lock is applied to the site collection to prevent users from altering data within the site collection while the move is taking place. Once the move is complete, the site collection is returned to its original lock state. The destination content database specified must already exist, must be attached to the same SQL Server as the site collection's current content database, and must be attached to the site collection's current Web application.

2 - I don't think we can find the exact time. But there won't be any down time. Users can still access the site, but won't be able to modify till the move completes.

PowerShell commands required

1. Find disk usage (Optional)

    $used = (Get-SPSiteAdministration -Identity <http://ServerName/Sites/SiteName>).DiskUsed
   

2. Trim audit data (Optional)

    (Get-SPSite -Identity <http://ServerName/Sites/SiteName>).Audit.TrimAuditLog(deleteEndDate)
   

3. Moving site collections between content databases

    Move-SPSite <http://ServerName/Sites/SiteName> -DestinationDatabase <DestinationContentDb>
   

Answer 2

1. When you run the move coomand, user will get correlation Id, sometime 404.typically this is advised to run in after hours, because you have to run iisreset after it.After you run the Move-SPSite cmdlet, run the IISReset command to update changes to IIS.
2. Their is no power shell or other method, which will tell you exact timings.its depend upon, hardware of server, load on server, size of site collection, network etc. Best thing to analyze or get estimate of this, you should do the some testing in lower farm.