Q:

Backup List in Sharepoint 2010 in Shell

I want to backup a List of Sharepoint 2010 using the powershell.
I can backup the list using the central Administration and can also backup the whole Site using 
Export-SPWeb -Identity http://siteurl:22222/en-us -Path \\public\backup.cmp

But when I try to export a specific List (with the path that is also shown using the Central Administration):
Export-SPWeb -Identity http://siteurl:22222/en-us/Lists/MyList -Path \\public\backup.cmp

I receive the error: 

"The URL provided is invalid. Only valid URLs
  that are site collections or sites are allowed to be exported using
  stsadm.exe"

I also tried
Export-SPWeb -Identity http://siteurl:22222/en-us -Path \\public\backup.cmp -ItemURL http://siteurl:22222/en-us/Lists/MyList 
getting the same error
Thanks in advance

A:

Try to fiddle with the ItemUrl parameter value:
Export-SPWeb -Identity http://siteurl:22222/en-us -Path \\public\backup.cmp
  -ItemUrl /Lists/MyList

or
Export-SPWeb -Identity http://siteurl:22222/en-us -Path \\public\backup.cmp
  -ItemUrl /en-us/Lists/MyList

or
Export-SPWeb -Identity http://siteurl:22222/en-us -Path \\public\backup.cmp
  -ItemUrl "/Lists/MyList"

Different sources show different syntax:

SharePoint 2010 Granular Backup-Restore Part 1
Failing to export with Export-SPWeb

A:

If you have the following kind of setup:

Site Collection e.g. http://localhost:81

|
    --> Subsite1 e.g. tools (http://localhost:81/tools)

|
      --> Subsite 2 e.g. admin (http://localhost:81/tools/admin)

I found the following worked for lists on the subsite:
Export-SPWeb -Identity http://<site>:<port>/<subsite1>/<subsite2> -ItemUrl /<subsite1>/<subsite2>/<listName> -Path <localpath>/<filename>.cmp -IncludeVersions All

e.g. 
Export-SPWeb -Identity http://localhost:81/tools/admin/ -ItemUrl /tools/admin/RequestList -Path C:/Temp/Backup.cmp -IncludeVersions All

To ensure you've got the right url for your list, use the following command (thanks to HAZET here: http://social.technet.microsoft.com/Forums/en-US/sharepoint2010setup/thread/a1f48e70-9360-440f-b160-525fbf2b8412/):
$(Get-SPWeb -identity  http://<site>:<port>/<subsite1>/<subsite2>).lists | ft title,  @{Name="itemURL"; Expression = { $_.parentWebURL + "/" + $_.RootFolder}}

e.g. 
$(Get-SPWeb -identity http://localhost:81/tools/admin/).lists | ft title, @{Name="itemURL"; Expression = { $_.parentWebURL + "/" + $_.RootFolder}}

Some examples of various errors I encountered whilst trying to get this to work:

The URL provided is invalid
Export-SPWeb :
<nativehr>0x80070057</nativehr><nativestack></nativestack> At
line:1 char:13
CategoryInfo          : InvalidData:
(Microsoft.Share...CmdletExportWeb: SPCmdletExportWeb)
[Export-SPWeb], SPException
    FullyQualifiedErrorId : Microsoft.SharePoint.PowerShell.SPCmdletExportWeb

Some things to check:

Check that -Identity has the trailing slash i.e. http://localhost:81/
Check that you have the complete URL in Identity (if using subsites, include subsites) 
Check that the path where you're trying to store your export file exists 
Check that your ItemUrl is correct (i.e. starts with / and is a directory, not a specific file e.g. is /tools/admin/RequestsList, not /tools/admin/RequestsList/AllItems.aspx
Check that you have permissions to perform the export

Further info that might be helpful:

Identity: The URL of your SharePoint site
ItemUrl: The relative URL of your list/document library
Path:     The target filename and location for the exported list e.g. C:/Temp/backup.cmp
IncludeVersion: What versions of the document you wish to export. 

Export-SPWeb
http://technet.microsoft.com/en-us/library/ff607895.aspx
Export a site, list or document library in SharePoint 2010
http://technet.microsoft.com/en-us/library/ee428301.aspx
Import a list or document library in SharePoint 2010
http://technet.microsoft.com/en-us/library/ee428322.aspx

