How to find out the ID of a site collection .

1. Open the Central Administration


2. Application Management


3. SharePoint Site Management


4. site collection quotas and locks

Select the appropriate site collection  and you will get the ID of that specific site collection



How to find out the ID of a subsite:

1. Save the current site as site template[.STP extension]


2. Save it to disk somewhere.


3. Now, navigate to that location and rename the file to .CAB extension.


4. Extract the CAB file and find the manifest.xml file.


5. Now, in the file check for the site ID/TemplateID string and get the value.


6. Navigate to end of this post for the TemplateID to Name mapping.

How to find out the List ID:

1. Navigate to the SharePoint list using the browser.


2. Select the Settings + List Settings menu command.


3. Copy the URL from the browser address bar into Notepad. It will look something like:

https://personal.collaborationtools.consumer.citigroup.net/personal/ag14178/_layouts/listedit.aspx?List=%7B47F2F5E2%2D6474%2D4929%2DB986%2D64BBE801C97A%7D



Delete everying before and including “List=”.

Change “%7B” to “{”

Change all “%2D” to “-“

Chnage “%7D” to “}”

You are now left with the Id:



{47F2F5E2-6474-4929-B986-64BBE801C97A}

Capacity Management - Site collection limits

Limit	Maximum value	Limit type	Notes
Web site	250,000 per site collection	Supported	The maximum recommended number of sites and subsites is 250,000 sites. You can create a very large total number of Web sites by nesting subsites. For example, in a shallow hierarchy with 100 sites, each with 1,000 subsites, you would have a total of 100,000 Web sites. Or a deep hierarchy with 100 sites, each with 10 subsite levels would also contain a total of 100,000 Web sites. Note: Deleting or creating a site or subsite can significantly affect a site’s availability. Access to the site and subsites will be limited while the site is being deleted. Attempting to create many subsites at the same time may also fail.
Site collection size	Maximum size of the content database	Supported	A site collection can be as large as the content database size limit for the applicable usage scenario. For more information about the different content database size limits for specific usage scenarios, In general, we strongly recommend limiting the size of site collections to 100 GB for the following reasons: Certain site collection actions, such as site collection backup/restore or the Windows PowerShell cmdlet Move-SPSite, cause large Microsoft SQL Server operations which can affect performance or fail if other site collections are active in the same database. SharePoint site collection backup and restore is only supported for a maximum site collection size of 100 GB. For larger site collections, the entire content database must be backed up. If multiple site collections larger than 100 GB are contained in a single content database, backup and restore operations can take a long time and are at risk of failure.

Perform a backup of a site collection Using powershell Command

Backup-SPSite [-Identity] <SPSitePipeBind> -Path <String> [-AssignmentCollection <SPAssignmentCollection>] [-Confirm [<SwitchParameter>]] [-Force <SwitchParameter>] [-NoSiteLock <SwitchParameter>] [-UseSqlSnapshot <SwitchParameter>] [-WhatIf [<SwitchParameter>]]
Identity -

Specifies the URL or GUID of the site collection to be backed up.
For example, a valid URL, such as http://server_name/sites/site_name or a GUID such as, "01234567-89ab-cdef-0123-456789abcdef"

Path  -

Specifies the full path to the backup file (that is, C:\Backup\site_name.bak.

Detailed Description

The Backup-SPSite cmdlet performs a backup of the site collection when the Identity parameter is used.

By default, the site collection will be set to read-only for the duration of the backup to reduce the potential for user activity during the backup operation to corrupt the backup. If you have SQL Server Enterprise Edition, we recommend that UseSqlSnapshot parameter be used because this ensures a valid backup while it allows users to continue reading and writing to the site collection during the backup.

Source : http://technet.microsoft.com/en-us/library/ff607901.aspx