ESXi 3.5 update 2 large datastore

[jelloguil]

Hi,

I've recently buy a new server and I would like to install vmware esxi 3.5 update 2 installable. The installation work, but when I want to make datastore he doesn't give me all the capacity of my drive. Here is my specs

Dell PowerEdge PE2950 with 2 Quad core xeon E5430, 16Gb of RAM and four 750Go SATA II configurated in one virtual disk on RAID 5 for a total of 3 TB.

In the VMWARE infrastructure client, I look in the storage adapter and he detect 1 disk (vmhba1) of 2.05TB so he miss 1TB but that I think it's the version of ESXi who's able to only 2.0TB, correct my if I'm wrong.

And when I want to configure the storage, I add new storage, I choose Disk/LUN, and my disk capacity is 2.05TB but available only 46.5Gb. Why the available space isn't near 2.05TB.

Did I need another version of VMWARE server, or did I need to split my array in 2 virtual disk of 1.5TB

Thanks

[Dave_Mishchenko]

Your post has been moved to the ESXi forum

Dave Mishchenko

VMware Communities User Moderator

[weinstein5 · Accepted solution]

You will need to split your disks up into RAID sets with less than 2 TB -ESX and ESXi only supports a maximum LUN size of 2 TB see . Also if you set the 4 disks in a RAID5 config you should have only gotten 2.25 TB os usable space - RAID 5 will be 3 usable disks with one spare -

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[jelloguil]

You'r right about RAID 5, I forgot that 1 disk isn't count for disk space. So I have a total of 2.25TB, I will delete my array and recreate with 2 disk. For VMWARE server, what is the best block size should I put?

And for the other question, why even If ESXi detect only 2TB, with my LUN available space is only 46GB?

*EDIT*

I made new array with 512k block size with 2 logical drive of 1.2TB each. The ESXi view all my drive and all the space is available for datastore.

Thanks

[JMills]

512kByte stripe width, you mean?

That might mean you're going to be straddling two stripes when you're performing disk I/O, depending on how you align the start of the VMFS3 partition on that system. IIRC we still only plan for a maximum stripe width of 128 kBytes.

As for detecting 46 GB, that may have been a high-bit truncation:

2048 GB (2 TB) + 46 GB = 2.0449 TB. With some helpful rounding, that's 2.05 TB, as you mentioned in your original post.

[Dave_Mishchenko]

If you don't mind me going a bit off topic, would you know why the LUN limit is 2 TB?

[JMills]

Short answer is that hitting or crossing the 2 TB boundary means that the total sector (512 Byte blocks) count for the device can no longer fit in an unsigned 32 bit integer.

The Officially Supported (caps-S definition here) limit is 2047 GB (2 TB minus 1 GB -or- 4294967296 minus 2097152 sectors), and the mathematical limit is something like 2^32 - 2 total sectors (4294967296 minus 2 sectors).

All Byte counts above are in 2^{10 (kiB) values not 10}3 (thousand Byte), i.e., reality not hard-drive marketing numbers.