Hi there, I have been testing the NVMe over TCP on my ONTAP box with VMWare 8. It works great... yet I cannot understand why it takes up so much space in the volume.
I started out creating a namespace using the web GUI, 150GB (no snapshots)
After a few minutes, my monitoring of the volumes started complaining because the default seems to be just 5-10% overhead so I added a little to the volume, and removed Fractional Reserve and enabled thin provisioning which was enabled by default.
I migrated a VM to the datastore of about 32GB (Thin Provisioned disks)..
I have now ended up with a namespace which seems to match the avaliable space in VMWare, but the volume in which this namespace is located still shows 150GB used no matter what I try to change... one strange thing observed is that the volume has "space-guarentee" set to "none" yet the "space-guarentee-enabled" option is set to "true", which makes no sese? I tried to upgrade to ONTAP 9.13.1P2 in hope of a fix.... but sadly no help.... am I just missing something here?
#NVMe thin provisioning?
formal lintel
floral sparrow
formal lintel
@floral sparrow sorry but this is different some how... I guess it's because of the NVMe namespace... If I configure the same volume with an iSCSI LUN, the result would be different... you should be able to configure a volume as thin, the LUN as thin and basically the volume should be close to empty because of it.. which is not the case with the NVMe namespace... maybe my first description wasn't that good? 😉
fathom garden
What about the space allocation option on the lun/namespace? May not be an option for NVMe but it was for luns and the default was disabled which means that the SCSI UNMAP doesn’t work until it’s enabled. But like I said, may not be an option with a namespace!
Also, I see you disabled snapshots but what about the snapshot reserve? If that isn’t 0%, maybe change that?
formal lintel
Well if I go into diag mode I can get this from the "nvme namespace show -ins"... "Space Reservation: true" but also "Space Reservations Honored: false" I have no way of changing this... not even if I try to create a new namespace.... so I guess "Thick" is the only way... the namespace size matches the used size in the volume... it confuses me that the name space has these options, yet you cannot change them...