1 Reply Latest reply on Jun 27, 2013 9:27 AM by rukbat

    solaris beginner asks : zfs reliability on single disk with copies=2


      I am a professional photographer and have a certain collection of precious photos (~1 TB) that I would like to store on an Oracle 11 system with one 3 TB physical drive. I read about Oracle 11s features and the ZFS. I want a cheap solution for reliable file storage of this 1 TB of photos with redundancy and error checking. Does Oracle ZFS provide effective reliability over a plain old NTFS on Windows 7 if I use just one ZFS volume with copies=2? Or are the benefits only realized if I distribute across multiple physical disks? I ask because I read this on Wikipedia about ZFS:


      "..... storing data on RAID-0 with a ZFS volume and "copies=2" enabled doesn't necessarily increase data reliability and can actually reduce it instead."

      But, discussions on other forums about ZFS on 1 physical disk + copies=2 say it is effective protection. I seek the tender of a certified/authority who understands this issue. If I move over my photos to a disk with a solaris ZFS volume with copies=2, do I get any data protection benefits? My common sense tells me if I use one physical disk with copies=2 then ZFS will give me protection against errors as it can look at the other copy for reference. But I am no expert

        • 1. Re: solaris beginner asks : zfs reliability on single disk with copies=2

          If you have one physical disk, you have one location. 

          It is irrelevant how many copies of various files you maintain on it.

          It is also irrelevant whether you choice a storage filesystem that duplicates things for you or whether you manually maintain copies.



          Consider the scenario of what happens  when your disk fails.

          When that fails you lose everything.


          You may need to review how important your files are to your business, your clients, your reputation. 

          Balance that against the choice to "do things on the cheap".

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