vSphere 6 guest unmap support (or the case for sparse se, part 2)
Hi, if you are a follow of my blog, you know how much space reclamation is a topic that is closed to my heart, in fact, almost exactly an year […]
Dell Storage, PowerStore, PowerFlex PowerMax & PowerScale, Virtualization & Containers Technologies
Hi, if you are a follow of my blog, you know how much space reclamation is a topic that is closed to my heart, in fact, almost exactly an year […]
Hi,
if you are a follow of my blog, you know how much space reclamation is a topic that is closed to my heart, in fact, almost exactly an year ago, I wrote this post : https://volumes.blog/2014/04/30/the-case-for-sparse_se/ which I highly recommend you to read if you want to get a full understanding of space reclamation, UNMAP and where is VMware in regards to this.
times are changing and im so happy that in 1 year, VMware had made some changes to UNMAP as well, is only a start but it’s a good one.
so what’s so different?
well, in vSphere 6, a guest VM can now issue an UNMAP and the ESXi host will not block it, is it a new thing?
The config option, EnableBlockDelete, is not new, it even existed prior to vSphere 6.0 (However description of that config option is changed in vSphere to reflect the actual implementation). However, prior to vSphere 6.0, Windows guests did not do the automatic UNMAPs because on the non-supportability of B2 mode page from vSphere side which is required by the windows 8 and above. vSphere 6.0 implements B2 mode page.
as long as the guest OS follows the alignment requirements reported to them in read-capacity16 and B0 mode page it will work
Caveats / Limitations
it’s not perfect, there are many cases where this will not work:
Still ok with you? You just upgraded to vSphere 6 and you are running modern guest OS’s like windows server 2012 and windows 8, great!, see the video I made below
2 Comments »