What size drives on vmware host

[lil328i]

Hi everyone,

If we are using iscsi SAN, and Vsphere 4, and would like to add a 3rd host to our infrastructure, what size SAS drives should we purchase.

The other 2 hosts are HP DL 365 G5's with 4 x 150 gb SAS drives in raid 5 with 32 gb ram each.

I think when we built them, we over-spec'd the hard drives in terms of capacity for hosts.

I undedstand that they would only be used for swap space for the vmware esxi 4 OS as all vm's are on the san anyway.

So, can we just purchase the smallest SAS drives that are made ?

Thanks!!

Peter

Orland Park Public Library

[AndreTheGiant]

So, can we just purchase the smallest SAS drives that are made ?

Yes, if you have a SAN.

In some cases (FC or iSCSI with hardware initiator) is also possible to boot from SAN and not use local disk at all.

Or if you plan to use ESXi you can consider to install on a SD/Flash memory:

Andre

[BenConrad]

I've been using the least expensive (10K RPM 72GB or 146GB) disks in a RAID-1 and have been skipping the array controller BBWC.

Ben

[lil328i]

Thanks for the link.

It should be located not on flash disk, ESXi on local disks works

without additional configuration and diskless ESXi have normal r/w

access to SAN only, so in this case you place scratchconfig on SAN.

With 32gb RAM and 10% memory usage, would there be aby performance hit with placing the scratch file on the SAN and going diskless?

I'm using ESXi4 on USB for both of my Hosts. Each host has is a RAID 5 box with 4 x 10000rpm SAS drives.

Would you recommend a OS re-install onto the raid 5 array? OR place the scratch file on the SAN and pull out the drives?

When I purchase a additional HOST, I think I will purchase without drives and just place the scratch file on the SAN, pending your recommendation.

Last, where in the configs would I go to place the scratch file on the SAN?

Thanks!!

Peter

[chaz112182]

im rocking 2 72gb drives configured as RAID1 array as well seems to work just fine

[lil328i]

is you esxi installed on Flash or the drives?

[AndreTheGiant]

Would you recommend a OS re-install onto the raid 5 array?

Seem's a lot of wasted spaced for the hypervisor only.

Or you plan to use also for VMs? (but is local storage so no cluster features)

IMHO, for ESXi a USB/Flash installation could be a good solution.

And you can make a dump and copy of your memory without big problem (you can use a block based copy).

Also there is a tool to handle ESXi backup/restore.

Andre

[lil328i]

We are running everything on the SAN.

So your are recommending to continue to use the Flash device, I have no problem with, as I've been doing this for 2 years now.

Should I then just set the scratch file to be run off the SAN? How do I do that?

Thanks!

[AndreTheGiant]

In this case follow the documents recomendation to have boot from SAN.

One LUN for each hosts.

Andre

[lil328i]

I dont think I would want Esxi 4 to boot from the SAN

I'm talking about the SWAP space.

How do I set the Host's SWAP space to be used on the SAN, as opposed on the drives of the host.

[Dave_Mishchenko · Accepted solution]

You can see this KB article - http://kb.vmware.com/kb/1004177. You can also update this with the vCLI.




Dave

VMware Communities User Moderator

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[lil328i]

Thank you for this link.

Last question, is there any performance hit in doing this?

We use 2 nic ports in TEEM mode to connect back to the SAN.

Peter