VMware Cloud Community
Querrtod
Contributor
Contributor

Raw Disk Question

Hey all

I've very recently purchased a Proliant Microserver that I plan on utilising as a file server and test bed. For this, I wanted to use ESXi to host two VM's. I was doing quite a bit of reading around and stumbled across this explaination on how to enable raw disk access. I'd like this because I'd like the ability to just rip a drive out and place it in another machine if I have to

http://cyborgworkshop.org/2011/01/08/enabling-raw-sata-access-in-esxi-free/

However I'm confused by this

"Now that we have the drive identified, we need to take that information  and create a drive map file. cd over to a datastore that is NOT a raw  mapping (i.e. I have a 500 gig drive in my box that hosts most of my vms  called SATA-500 in /vmfs/volumes/SATA-500, so I would cd into there)"

My set up is going to be like this

USB - ESXi
VM1 (File server)
1tb - OS and temp download storage
1.5tb - Movies / Music
2tb - TV
VM2 (Test server)
60gb (SSD)

I'm not sure where I should actually create the "drive map file" in this  scenario???? I want all the drives in the VM's to be raw mapped. Would I  need to add another drive just for the mapping file?

Reply
0 Kudos
6 Replies
Sreejesh_D
Virtuoso
Virtuoso

the map file has to be located in  a VMFS volume. In your case a VMFS volumed need to be created first on local disk. Once its created CD to it.

1. CD to vmfs datatstore. eg:- cd /vmfs/volume/<datastore>

2. Run vmkfstools

vmkfstools -z /vmfs/devices/disks/ RAW-2TB.vmdk -a buslogic

Reply
0 Kudos
Querrtod
Contributor
Contributor

Could I just partition off the rest of the USB stick (it's 8gb, so more then I need for ESXi) and place the mapping files there? What size are those files usually and would this cause performance degredation?

Reply
0 Kudos
Sreejesh_D
Virtuoso
Virtuoso

we cant create VMFS volume on USB flash drive, its not supported.

Reply
0 Kudos
Querrtod
Contributor
Contributor

Ah that's a shame, seems such a waste to use another complete drive just for a few mapping files

Can you map partitions or only full drives? Was thinking I could split off a small section of the os drive of VM1 for the mapping files

Reply
0 Kudos
Querrtod
Contributor
Contributor

Ok so far I've been able to get vSphere client up and running and connecting to my host

I've put in another drive for VM storage and have added this as a datastore. Additionally I have created the mapping files on the drive for the other drives that I want to have raw access

Now however when I try to create the Virtual Machine, it asks me to Select a Disk. However Raw Device Mappings is greyed out and when I try to Use an Existing Virtual Disk, it only allows me to select the drive I included in the datastore

How do I get around this? I figure I've missed a step

Reply
0 Kudos
Querrtod
Contributor
Contributor

Don't worry... I'm a moron! Just realised if I double click on the "VM Storage" datastore, it actually goes into it and shows my raw vmdk files! *slaps forehead*

Think I may have it all under control now. I've got the OS vmdk sitting on an additional drive (same one I used for the mapping files) and have set up the three raw drives in the VM as well

Reply
0 Kudos