1 Reply Latest reply: Sep 23, 2013 1:03 PM by Cindys-Oracle RSS

    Reg max zvol capacity calculation from zpool storage

    lksece2

      Hi There,

      I have created a zpool (mirror 10) from the SAS HDDs. I would like to create maximum zvol that can be created from the zpool. Is there any calculation I can use for this?

      When I try the capacity which I got from zpool iostat then it says the space is not available.

      For example if zpool iostat gives 5G as free space then it I try to create 5G zvol then it says out of space. How to find out the max capacity which I can enter without the error?

       

      Thanks in advance.

        • 1. Re: Reg max zvol capacity calculation from zpool storage
          Cindys-Oracle

          I would recommend using zpool list and zfs list to determine how much space is available. You can use the pool commands like zpool iostat alone.

           

          For example:

           

          The pool status says that 3.57 M is allocated but the zfs list output says 10.3G is allocated because of pond/vol1.

           

          # zpool list pond

          NAME  SIZE  ALLOC   FREE  CAP  DEDUP  HEALTH  ALTROOT

          pond   68G  3.57M  68.0G   0%  1.00x  ONLINE  -

          # zfs get volsize,used pond/vol1

          # zfs list pond

          NAME   USED  AVAIL  REFER  MOUNTPOINT

          pond  10.3G  56.6G    38K  /pond

          # zfs get volsize,used pond/vol1

          NAME       PROPERTY  VALUE  SOURCE

          pond/vol1  volsize   10G    local

          pond/vol1  used      10.3G  -

           

          Sizing volumes is important so you don't fill them to capacity. You need to monitor the volsize of the volume.

           

          The zpool status command does not account for unused volume space of the created volume, but zfs list does.

           

          Thanks, Cindy