Writing to PR4100, copied folders are considerably smaller than originals

Hi there. I’m a happy owner of a new WD MyCloud PR4100 with four 10TB Red drives in it.

My first task after set-up is to copy about 5TB of data from a fairly old Drobo, then wipe the Drobo for another purpose. At the end of the two-day copying process I’ve gone in to check the files and compare them over the two devices. Most of the data seems to have copied successfully but with two or three very big folders (tens, maybe hundreds of GB), the folder on the PR4100 is much smaller than the original folder on the Drobo.

I am able to view hidden files and when I compare the two sets folder by folder and file by file, they appear the same. There are a few random ‘destop.ini’ files and those weird ‘.DS_Store’ things left by Macs, but otherwise the folders match.

So why would folder properties on the Drobo say it has 18,000 files and 200GB, yet properties on the PR4100 version reports 5,000 files and just 50GB of data?

Sorry if this is more a data or Drobo question than a WD phenomenon, but I’ve had help here in the past.

Hi martynmoore,

After copying the large files, My Cloud starts to indexing the copied data after which we would be confirm about the complete copied data. This smaller size as comparable with the original might be due to incomplete indexing of copied data. I would recommend to let the indexing complete and then check the size of copied data.

Thanks very much asp73. I’ve left the NAS over the holiday and am about to go back to work, so will check to see if the reports match now. I will report back. The other possibility is that Windows Explorer struggles with long file names, so if the root to a file includes long names of folders, followed by a long file name, then that file might not be included in a report by Windows Explorer properties. I used FreeFileSync to compare the folders and files and it reports that everything is present and correct on the NAS, when compared to originals on the drobo. I’m keen to get the drobo wiped, so will let you know what I find today.

I’ve just checked the properties of original folders on drobo with those of copied folders on my PR4100. They still report huge discrepancies. However, if I drill down into those folders and compare included files and folders, they are all the same - on drobo and PR4100. A folder with ten folders, each containing 120 files, looks the same on drobo as it does on the PR4100, even when Windows Explorer Properties reports they are different at the top level. It’s very confusing. But once again, FreeFileSync reports them as the same. At some point I’m going to have to wipe and format this drobo but I’ll leave it a few more days in the hope that somebody can explain why the copied folders’ properties are smaller than those of the originals. Is it the long file name thing?