1 Reply Latest reply: Dec 14, 2016 7:16 AM by Nick Dyer RSS

    About sweeping process, is there any docs describing the details about this? Everybody says that it has no impact on the performance, but how does this happen?

    Tony Jing Newbie
    Visibility: Open to anyone

      About sweeping process, is there any docs describing the details about this? Everybody says that it has no impact on the performance, but how does this happen?

        • Re: About sweeping process, is there any docs describing the details about this? Everybody says that it has no impact on the performance, but how does this happen?
          Nick Dyer Pioneer

          Hi Tony,

           

          It's part of the IP and patents within NimbleOS (aka CASL) so there's no publicly facing documents that detail sweeping. However what can be said is that NimbleOS is a log structured file system which has built-in system wide garbage collection. As blocks are purged/deleted, the filesystem will re-load fragmented stripes into DRAM, perform a re-sequentialisation of said stripe into a new full RAID stripe and then restripe across the disk media. This runs all the time - it's not a scheduled process. It allows the capacity of the system to be populated up to 90% full without problematic issues such as fragmentation, read/write latency or outstanding disk queues.

           

          If you attend one of Nimble's NTS 1-day training courses we go into it a bit deeper there as part of the file system overview.

           

          It's a bit old now - but there's a CASL Deep Dive video on YouTube which may provide you with answers.