I have 2 shares on a server, X:\ and Y:\.

These 2 drives hold 2 terabytes each of what is supposed to be identical files and folders.

They don't appear to be the same. What I want to do is compare the two drives and list any anomalies.

thepowershellguy.com/blogs/posh/archive/2007/01/27/hey-powershell-guy-how-can-i-get-a-list-of-all-the-subfolders-in-a-folder-and-then-put-that-list-into-an-array.aspx

The above link demonstrates how to recursively list all folders and subfolders from a particular directory. Below is the actual code.

$dirs = dir -Recurse | Where {$_.psIsContainer -eq $true}

$dirs | select fullname

Now, with all that said, what would be the best way to compare these two drives? The above PS code does not show size of folders, but I would be satisfied with something that would just compare folder existence when compared.

I don't even know if all the folders and subfolders could fit into a PS array. Should I bring the both drives into arrays and then somehow compare the arrays? What suggestions could you guys scrounge up? 

Here's an outline (I don't have time to code it right now):

Loop through the first drive, adding each path\filename to a CSV file

Load the CSV file into a hash table (the key is the path\filename, the value can be anything you want to compare: size, mod date, etc).

Loop through the second drive, looking up each item in the hash table

If you find it, compare the size/moddate/whatever and report as desired; then DELETE it from the hash table

If you don't find it, report that the file only exists on the second drive

Loop through the hash table, reporting all remaining files as only existing on the first drive

Possible enhancement: if the list of files is too big for a hash table, add some sorting logic to process on folder at a time.

yeah :) I saw those. Working on the issue right now. Will respond with the end results and final code :)

That is what I started to do but I ran out of memory trying to capture the first drives data. Guess I will be doing it a little at a time. Can you append to a file using export-csv?

Trying the following now.

# Target locations to compare
$Target1 = Get-ChildItem "M:\" -name
$Target2 = Get-ChildItem "M:\" -name

Write-Host '$Target1 and $Target2 Comparing:'
Compare-Object -ReferenceObject $Target1 -DifferenceObject $Target2
Write-Host '$Target1 and $Target2 Compared.'

ForEach($SubFolder In $Target1)
{
    $Folder1 = "M:\" + $SubFolder
    $Folder2 = "N:\" + $SubFolder
    Write-Host "$Folder1 and $Folder2 Comparing:"
    Compare-Object -ReferenceObject $(Get-ChildItem -Recurse $Folder1) -DifferenceObject $(Get-ChildItem -Recurse $Folder2)
    Write-Host "$Folder1 and $Folder2 Compared."
}
Write-Host "Done!"

Hope it works. Taking forever! :(

Please tell me that it is accepting those variables in there after my appends and I didn't monkey it up. I would hate to be waiting for this to be done only to find out that nothing is being compared or what I want isn't being compared.

This is a large quantity of files. I help support an electronic medical record system at a hospital, umong other things. Eight-ish years of scanned images and text files.

The reason that I am trying to test this is because, unlike other system that require us to do replication for disaster recovery, this system writes the documents to 2 seperate locations on its own. The problem is that I don't think it did a perfect job. That is what I am trying to find out :)

Edit: Just noticed that my script is checking the M drive against the M drive at the top. That is ok. That particular piece has already been checked before. So, don't worry about it. The bottom half of the script is still right and that is what I am truely looking at anyway :)