Question about SSD use

Discussion in 'General Returnil discussions' started by newbino, Jun 14, 2012.

Thread Status:
Not open for further replies.
  1. newbino

    newbino Registered Member

    Joined:
    Aug 13, 2007
    Posts:
    377
    Hi, I am thinking about trialing Returnil System Safe free. My OS (Win 7 x64) is on an SSD.

    On the manual it reads that SSD are in the Supported Hard Disk Drives configurations.

    I also reads in the FAQ
    I am not sure I understand "do not yet support disk write minimization" could somebody elaborate?

    Any other comments on the topic welcome :)
     
  2. Coldmoon

    Coldmoon Returnil Moderator

    Joined:
    Sep 18, 2006
    Posts:
    2,981
    Location:
    USA
    Hello newbino,
    Write minimization is a goal for solid state drives due to their inherent physical limitation on the number of life-time writes each sector of the disk will support. With virtualization however, there is potential for some sectors of the disk to be heavily used due to the use of a cache.

    One way to minimize the potential issues, extend the life of the disk, and to increase system performance; some have employed methodology where they only allow reads from the SSD (like flash media, this is much faster on a SSD than a platter drive) while restricting writes to a sacrificial platter drive which is much faster at this process than a SSD.

    SSD = faster reads
    platter = faster writes

    The multi-disk virtualization in RSS/RVS support moving the virtual system cache for non-system disks and partitions to a different drive or partition which in this scenario would be the sacrificial platter drive. Due to limitations in the Windows OS platform however, this "shifting" of the (usually C:\ drive) cache to a sacrificial platter drive is not possible as the cache for the System Partition MUST be on the System Partition and this is why write minimization is not fully realized in the software.

    Mike
     
  3. newbino

    newbino Registered Member

    Joined:
    Aug 13, 2007
    Posts:
    377
    Hi Mike and thanks for your reply.
    this does not tally with what I know, and certainly not with the performance of my drives (attached: 1st SSD 2nd HDD)

    Apart from this, if I understand your points:
    a. RSS/RVS creates a virtual system cache
    b. due to limitations in the Windows OS platform the System Partition cache MUST be on the System Partition
    c. write minimization is not fully realized in RSS/RVS due to b)

    If this is correct, than the question becomes: how can we quantify the impact on "some sectors of the disk ... heavily used due to the use of a cache"?
     

    Attached Files:

    • SSD.png
      SSD.png
      File size:
      28.5 KB
      Views:
      232
    • HDD.png
      HDD.png
      File size:
      28.3 KB
      Views:
      231
  4. Coldmoon

    Coldmoon Returnil Moderator

    Joined:
    Sep 18, 2006
    Posts:
    2,981
    Location:
    USA
    Unlike those solutions that use a static cache approach, the caches in RSS/RVS are dynamic and may or may not use the same free disk space to create the cache with each boot session so it is very difficult to get into the weeds of this as the scenario is more potential than with those solutions using the same exact space over and over to divert and track disk writes.

    Flash media is getting more robust as time passes, but still has a limitation on the number of times a sector can be written to with the traditional platter drive having a higher tolerance and thus, greater life span (potentially) than the SSD.
     
  5. newbino

    newbino Registered Member

    Joined:
    Aug 13, 2007
    Posts:
    377
    thanks Mike

    PS a further question, if you don't mind: what are the relative merits of static vs dynamic cache approaches? Thanks!
     
    Last edited: Jun 19, 2012
Thread Status:
Not open for further replies.