09 mars 2011

Thin provisioned disks and VMFS fragmentation, do I really need to worry?

I’ve seen this myth floating around from time to time and as I never publicly wrote about it I figured it was time to write an article to debunk this myth. The question that is often posed is if thin disks will hurt performance due to fragmentation of the blocks allocated on the VMFS volume. I guess we need to rehash (do a search on VMFS for more info)  some basics first around Think Disks and VMFS volumes… When you format a VMFS volume you can select the blocksize (1MB, 2MB, 4MB or 8MB). This blocksize is used when the... [Lire la suite]
Posté par jcdemarque à 14:12 - - Commentaires [0] - Permalien [#]
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09 juillet 2010

Stockage: HP s'adapte au client virtuel (VDI) et ouvre ses 'clusters' EVA

Retour sur les annonces de HP, fin juin: une baie SAN 'Lefthand' P4800 en 'blade' et un 'cluster' EVA supportant jusqu'à 1,9 peta-octets... --> Le reste est sur le site : http://www.silicon.fr/fr/news/2010/07/09/stockage__hp_s_adapte_au_client_virtuel__vdi__et_ouvre_ses__clusters__eva
Posté par jcdemarque à 22:53 - - Commentaires [0] - Permalien [#]
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24 avril 2009

Thin provisionning, what? Save diskspace with ESX and vSphere, oh yes…

Just to say it, because it is one feature MS Virtual Server and Hyper-V have that was missing ESX in GUI vCenter... the article : I was always very happy with one of the features present in VMware Workstation since few years now. Actually you are able to specify in VMware Workstation when you configure new virtual disk how big the disk will be. But when you specify for example 50 Gigs virtual disk inside Workstation , the disks real space on your PC gets just few hundred Ko. The vmdk file which is laying on your hard disk will... [Lire la suite]
Posté par jcdemarque à 07:36 - - Commentaires [0] - Permalien [#]
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24 mars 2009

An 8MB VMFS blocksize doesn’t increase performance?

VMFS Blocksizes have always been a hot topic regarding storage performance. It has been discussed by many including Eric Siebert on ITKE and Gabe also opened a topic on VMTN and he answered  his own question at the bottom. Steve Chamber wrote a great article about Disk Alignment and Blocksize on VI:OPS which also clearly states:”the VMFS block size is irrelevant for guest I/O.” Reading these articles/topics we can conclude that an 8MB blocksize opposed to a 1MB blocksize doesn’t increase performance. But, is this really the... [Lire la suite]
Posté par jcdemarque à 16:18 - - Commentaires [0] - Permalien [#]
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