How to use 2TB and up hard drives, with ESXI 5.5?

Is there any way to get ESXI 5.5 "around" the 512 byte limit described in this KB article?


I would like to be able to have ESXI utilize a host with a bunch of 2.5inch 2 TB or 3TB drives in hardware RAID 5 as a local data store, but I am worried that it will not be able to see any space above 2TB.  How is ESXI able to support 16 TB volumes?  How is it able to do this if it cannot address single HDs bigger than 2TB?  I am guessing it can when you have many smaller drives in a SAN RAIDed together?

Is there a way around this?  Either by having the RAID card somehow hide this or hardware emulate present it to ESXI?  I know hyper-v doesn't have this problem, but then again, Microsoft has no cluster based file system.

Thanks for your insight.
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
You can

1. Create a RAID array, of many disks to create a large datastore.

2. Create a single datastore on a single disk, and then add another disk to it, to expand the datastore.

(this is dangerous, because if a disk fails, the entire datastore will fail)
CnicNVAuthor Commented:
I know this is an advanced an only related side question (so I will of course award you for your original question), but do you know why VMware has not fixed this yet?  Like is it some limitation of their cluster based file system VMFS 5, or is it a limitation of the ESXI 5.5 hypervisor.  Where I am going with this is, could I theoretically point ESXI 5.5 at a NFS (also cluster file system?) data store instead of VMFS, and would this allow it to use these drives?

Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
what limitation ? fixed what?

the maximum size of a vmfs datastore is 64TB, and has been since ESXi 5.0. Before that in 4.x, it was limited to 2TB-512bytes.

You can always use a NFS export on Windows, Unix or Linux to present to ESXi, and use the native file system for virtual machines, e.g. as a datastore (non-VMFS).
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CnicNVAuthor Commented:
What I mean by limit is the 512 byte limit disk sector size for VMware vSphere and VSAN.  For example, what we are trying to do (with our budget), is squeeze the most value out of an upcoming server purchase.  We were going to opt for an 8 HD bay Dell server (for room to grow), loaded with 4 times (>2TB 2.5 SAS drives) and RAID 5 them.  All being managed by a PERC 730, but are worried that we will have to purchase 1TB drives instead because VMware does not yet support 4k bytes sector size.

...But it looks like you address this in your original point 1.  But yeah, I was just wondering.  So I guess the limitation is on ESXI recognizing physical hard disk sector sizes as apposed to logical data store "spanning" size (lack of a better term).  So not a VMFS limit, must be ESXI HAL issue...I dunno.

I hope this makes sense, I may be getting confused.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
4k sectors not an issue, your RAID controller deals with them!

that's presented to VMware vSphere (ESXi), which uses VMFS, with block and sub block sizes of 1MB and 8kb respectively.

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CnicNVAuthor Commented:
Ok, thank you sir.  As always, I appreciate the help.
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