This may be a simple answer, but I am genuinely curious and would like to know the ramifications of something I am planning to do. Maybe it is an easy answer as well!
Say I create a volume, let's say for the pointless sake of argument it is mirrored striped vdevs of 10x2x3TB (20 devices, 10 mirrored sets). I then share this out with iSCSI to a hypervisor and fill up 50% of my capacity (15TB) with vMotion (vastly sequential writes). Soon after this I decide to remove (either delete or vmotion to another storage device) one of the virtual volumes (vmware vmdk) that I am storing on there, let's say it is 3TB.
Would this cause less fragmentation for my ZFS filesystem than normal copy on write changes to the data? Will ZFS see this as free space and write sequential stripes into this space after it is vacated?
Part of the reason I ask is I have noticed that when I evacuate VMFS volumes which live on FreeNAS, VMware reports the new free space but the RRD graphs in FreeNAS reporting section under partitions don't seem to ever go back down.
Thanks for any insight anyone has!
Say I create a volume, let's say for the pointless sake of argument it is mirrored striped vdevs of 10x2x3TB (20 devices, 10 mirrored sets). I then share this out with iSCSI to a hypervisor and fill up 50% of my capacity (15TB) with vMotion (vastly sequential writes). Soon after this I decide to remove (either delete or vmotion to another storage device) one of the virtual volumes (vmware vmdk) that I am storing on there, let's say it is 3TB.
Would this cause less fragmentation for my ZFS filesystem than normal copy on write changes to the data? Will ZFS see this as free space and write sequential stripes into this space after it is vacated?
Part of the reason I ask is I have noticed that when I evacuate VMFS volumes which live on FreeNAS, VMware reports the new free space but the RRD graphs in FreeNAS reporting section under partitions don't seem to ever go back down.
Thanks for any insight anyone has!