We help IT Professionals succeed at work.

ESXi - Span Datastore across multiple SATA HDD, or Create OpenFiler VM and use iSCSI

Hi gang,

I have noticed that in ESXi 5 it is possible to create a datastore on a SATA drive and then expand it on to more drives. I am wondering what sort of performance this is likely to give vs creating an openfiler VM, adding all the discs into an array and then creating an iSCSI target to use for my other VMs?

I have attached the screenshot of a 6TB datastore created by expanding across 6 x 1TB HDD.

This is for a non critical server, so no need for comments regarding redundancy.

Thanks for the help!
Datastore.png
Comment
Watch Question

VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017
Commented:
It will be poor in comparison with a RAID set, because you are not stripping the data across the 6 disks, it's just an expanded datastore across 6 sequential disks.

In a RAID set, multiple disks = multiple spindles = more combined IOPS of the disks, as it's stripped.

I think you would be better off, using Oracle Solaris Express 11 (fatest and best), Openindiana, Nexcenta and use a ZFS presented NFS or iSCSI solution, with your six disks.

here are some examples

just as an example of 5,400 rpm SATA disks, not on a particular fast system

two disks - 84.5 MB/s Write,  150 MB/s Read
four disks - 196 MB/s Write, 276 MB/s Read
eight disks - 212 MB/s Write,  287 MB/s Read

You can also create the same solution in a VM with the above, it's called Storage in a Box, where you use DirectPath, so Solaris accesses the SATA drives directly, and then you allocate all 6 drives in a ZFS array.

That's your best option if you want performance.

ZFS!

Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
you will probably find, Openfiler, is faster, than your 6 Disks Expansion.

Also note, if a drive fails, you will lose the datastore completely.

ZFS, can be configured, so it's redundant and will tolerate disk failure.

Author

Commented:
So Esxi does not stripe data  across the discs in the expanded datastore ? I can't find any info on it.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
no, it just expands the vmfs datastore, normally your datstore would already be stripped e.g. Hardware RAID presented to ESXi.

single disk sata support is very slow, not many IOPS per disk.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
ESXi contains no drivers to do RAID, it expects a hardware solution.

Try Oracle ZFS Storage in a Box!

or purchase a supported RAID card.

Author

Commented:
the only hit I get to a "storage  in a box" search is one of your  earlier posts. Do you have a link to the download site by any chance?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
Storage in a Box or All in One

This is the fastest solution! (built on Oracle Solaris Express 11)

http://www.napp-it.org/napp-it/all-in-one/index_en.html

Author

Commented:
Would you mind giving me an idea of how long it would take to get OSE11 installed, NAPP installed and configured on top for someone unfamiliar with those products?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
With EE help, 2-3 man days depending on your skill level.

Author

Commented:
I have installed Solaris Express 11 but when running wget -O - www.napp-it.org | perl
I get 42.0.17.88:80 connection failed. Any ideas?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
CERTIFIED EXPERT
Fellow
Expert of the Year 2017

Commented:
The setup of Solaris Express 11 as a NAS, is off topic.  If you are happy with the answer, please assign points, and open a new question, and myself or other Experts will be happy to assist.