VMFS and VMFSL in ESXi 7 - what is the difference ?

[continuum]

The new VMFSL filesystem inroduced with ESXi 7 identifies itself with the
GUID 4EB2EA3978554790A79EFAE495E21F8D while regular VMFS identifies as
GUID AA31E02A400F11DB9590000C2911D1B8.
vmkfstools -P makes no difference between them: both are VMFS 6.82
Resourcefiles and magic values also seem to be the same.

So why the new label ?
Where can we look up the specs of both filesystem like : allowed filesize, allowed filenumber ....

[Nawals]

Is this link may help you.Virtual Maestro: Disk partition layout for ESXi in vSphere 7

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Hi

did you see anything in that link that would help ?

If yes - please  tell me what you had in mind,

Thanks

[Nawals]

In that link not mentioned about why level VMFS-L. But i heard from my colleague that,  the VMFS-L file system is for vSAN. Leaf level vsan objects reside directly on VMFS-L volumes. That are composed from server side direct attached storage. File system format is optimise for DAS. Optimization include aggressive caching with for the DAS use case, a stripped lock down lock manager and faster formats .

[a_p_]

VMFSL (VMFS-Local) is actually not new. IIR it was first introduced with vSAN, and one of the main differences it that it is sues as a local file system, i.e. only accessed by a single host, and therefore doesn't require the same locking mechanisms as a shred file system.

What I can't tell you, is why VMware decided to consume up to 120GB disk space for the VMFSL partition for new installation, and doesn't allow to create VMs on it. Well, sure the files in that partition should be protected from accidental modifications, but still, why 120GB?

André

[tayfundeger]

This is a topic I am curious about :smileyhappy:

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Andre - do you have any idea about a new feature that needs a significantly higher amount of allowed files per volume ?
ESXi 7 now allows millions of files on a volume where it allowed 16000 with ESXi 6 ...
According to my first tests those high numbers of files are not handled well.
ESXi 7 fails to list the content of a datastore way before you reach the new limits.

[a_p_]

No sorry, no idea at all. I couldn't find anything related in the documentation either yet.

André

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During the beta ESXi would crash if you get close to the new max - now it seems to handle it slightly better.
The host does not crash but the content of the datastore is lost / unaccesable.
Wonder what feature justifies such a risky implementation ???

[AbhijeetD87]

Hi everyone,

I just came across this thread as the link shared is from my blog. Would like to put my initial thoughts on this topic.

VMFS-Local (L) was bundled alongside vSAN initially with on disk format version 1 that was in vSphere 5.5 and 6.0. Later it became Virsto or vSAN FS in v2  It is treated as lighter version of VMFS as it has overhead of 750 MB per HDD.

VMFS and VMFS-L, they do share some basic structure. So VMFS-L is a VMFS flavour, That is why you see VMFS properties in VMFS-L

VMFS is designed to be cluster aware file system and it is optimised for concurrent cluster operations like metadata operations towards storage solutions.

VMFS-L came into picture with vSAN bcoz vSAN works with object storage using locally attached storage. So VMFS-L is optimised for object based storage.

Talking about ESX-OSData, it holds previously know partitions like diagnostic, syslog, store. How much it consumes, depends on what disk you have used during installation. When I did test with minimum on 8 GB disk, it took roughly 6 GB and rest for Boot Banks and pre-boot. Not sure what are the calculations behind it though.

I hope it adds some value to this thread. Will add if come across more info.

[continuum]

> It is treated as lighter version of VMFS as it has overhead of 750 MB per HDD.
What do you mean with "overhead of 750 MB per HDD" ?

The size of the metadata for a VMFS-L volume and a VMFS volume is almost the same - it starts with 1.5 Gb

[AbhijeetD87]

Here it is explained about VMFS-L overhead

Formatting Overhead Considerations | VMware® vSAN™ Design and Sizing Guide | VMware