Problem compressing large and very large files (NTFS compression, +50GB file)


  • I have a Dell PE R710 file server for my 150 users. 16 GB of RAM, 5 SAS 15K RPM disks in RAID-5 and on CPU dual-Xeon 5550

    I have a scripted routine to backup my Hyper-V VHD files and works well.

    Recently we have changed and the partition used have to be compressed (NTFS native compression) and the copy routine of the  VHDs files caused a serious problem on the server.

    1) the script (using native robocopy) does not work anymore, hanging, making some backups, others not

    2) The file server hangs entirely, users begin to lose access to their folders, no one can log in locally, TS, nothing

    The only solution is to reboot. Using explroer, robocopy, any method the problem is always the same

    The VHD files are form 7GB, 25Gb and sometimes 60GB files and 850GB in total.

    There is a problem in WIndows dealing with NTFS compression of large files?


    Friday, December 09, 2011 12:00 PM

All replies

  • My reply is missing.

    It is known that Robocopy has performance issue when handling large size of data. Also copy large files to an compressed folder will also use certain system resource. Thus the result may be caused by these 2 actions.

    Have a test to only copy 1 file to target folder and see if issue still exists. If not then you may consider backup files in batch as a workaround (or backup to a differernt and compress it later).


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    Friday, December 16, 2011 8:47 AM
  • I have no problem in using the same tool (robocopy) to copy 900GB of files to a non-compressed partition/volume and the problem also occur using Explorer.exe and other tools. The problem, IMHO, is only related to the compression state of the partition/volume

    It´s odd to me that a OS can allow users to do actions that can cause instability to the system. It´s odd to me that it is happening in 2011 with super-hardware and brand new OS, not NT systems or vanilla hardware...



    Friday, December 16, 2011 11:33 AM