1 Reply Latest reply: May 6, 2011 2:25 PM by Nik RSS

    Readzillas in New Oracle ZFS 7000 Storage

    860120
      Hi,

      Just want someone to clarify one thing for me. Number of people are saying that we need Readzillas (L2ARC) Read cache to improve the read performance. But is it a must?

      Given the controller (an x86 machine) already contains certain amount of DRAM ,e.g 72GB, would be sufficient?

      When I compare to other SAN, such as HP EVA, Hitachi AMS, their controller caches are normally less than 20GB. It seems the Oracle ZFS storage already has a lot more.

      Am I missing something here?

      Or it is still recommended to purchase additional read cache (L2ARC) for performance purpose in new zfs 7320, 7420?

      Thanks.
        • 1. Re: Readzillas in New Oracle ZFS 7000 Storage
          Nik
          Hi.
          it's depend :)
          7000 storage based on SATA (or SAS nearline ) disks 7200 rpm.
          This disks can't do good performance on random access. For compromize it need give more cache. More RAM or add SSD disks as cache.

          In this case SSD disk is more price effective.

          ReadZilla used as cache for random request. It's not give benefit on sequental read.

          In case you will be use 7000 with NFS sync mode, recommend add WriteZilla disk to.


          In any case for give recomendation for configuration need know how it will be used.

          Regards.