VMware Cloud Community
ubisec
Contributor
Contributor

Expanding HD space in ESX 3

Noob question, here...

I am planning on using a single server with local storage for my initial VMware ESX deployment and was wondering how difficult/burdensome it is to add HDs and increase space?

I'm planning on starting with maybe 300GB or so in a RAID 10+0 configuration and want to be able to add space to the mix over the course of the year, as needed.

Please let me know.

Thanks,

Ed

Reply
0 Kudos
6 Replies
merse
Hot Shot
Hot Shot

One option is to simply create a new logical array and set it up as an additional VMFS volume or if you wanted to increase your existing array you could backup the contents of your existing VMFS, trash it and create a bigger array, format with VMFS and copy your stuff back and reregister the VMs.

But in a year I'll wager that you're running at least 3 SAN connected ESX servers hosting some of your production environment... :smileysilly:

Reply
0 Kudos
ubisec
Contributor
Contributor

What's the best practice regarding arrays? Should I be creating multiple arrays for redundancy or performance somehow anyway?

Also, if I decide to keep a single array and grow that, is that an arduous process? Or is it pretty simple and has a low failure rate?

Thanks,

Ed

Reply
0 Kudos
Dave_Mishchenko
Immortal
Immortal

There's no expand partition option like you could with Windows. For ESX you would typically add another RAID set / storage LUN and then add an extent to an existing datastore to expand it. Generally, if you can avoid extents that's better. For data store size people will range between 300 - 500 GB (you'll see bigger if you're dealing with something like a file server which would need very large VMDK file). You'll also want to limit a single data store to 10 - 15 VMs. That's more important with shared storage because you can end up with issues due to SCSI reservations (i.e. a single ESX host has to lock the entire datastore for certain file operations which briefly pauses I/O to all VMs on the data store).

Reply
0 Kudos
ubisec
Contributor
Contributor

Dave,

When you say "add another RAID set" are you saying in hardware? Like I would need another RAID card? Or was this in software?

What is an "extent"? Is that a term referring to extending the storage space?

Lastly, when you say to "limit a single data store to 10-15 VMs" are you saying that I shouldn't run more than 15 VMs on a single server? Does this apply to local storage, as well (I'm not considrering a SAN at this time). The Dell benchmarks on a single server with the specs I'm looking at capped out at about 30 servers running concurrently.

Thanks,

Eddie

Reply
0 Kudos
pngsysadmin
Contributor
Contributor

I believe that he is saying that you will have to either add more disk to the existing array or add a second array to the controller, if yours were to support that option.

An extent is a VMware term used to describe how the disk is expanded, caution it is not necessarily the same thing as expanding a drive in Windows.

With 300Gb for your local datastore I doubt that you will attain 30 VM's on a box, however, you could if the OS and actual data stays small enough, I would say that at 12-15 VM's with 10Gb OS boot storage, you will not have enough disk space.

I am planning a clustered environment with 10-15 VM's per ESX server and have 300 GB just for the boot os, all the data is on RAW data LUNs off of our SAN. Conceivably 1-2TB of data total with OS and DATA LUNs.

Reply
0 Kudos
Texiwill
Leadership
Leadership

Hello,

Adding a disk to an existing VMFS is not an option as there is no way to resize the VMFS. However you can add a new RAID set within your controller and make a new VMFS on that RAID set. You can even join the 2 distinct VMFS into a single volume using Extents within ESX. However, Extents are not really recommended.

If for example you have an existing 4 300GB drives in a RAID 10 Raid Set, on this is one VMFS. In order to increase the VMFS you would need to add say 4 more 300GB drives in a second RAID 10 Raid set. This secondary RAID 10 Raid set can be formatted as a distinct VMFS and then joined to the primary VMFS using the Extent mechanism within the VIC. However, if it was me, I would just have 2 VMFS volumes and not join them together as one.

Best regards,

Edward L. Haletky, author of the forthcoming 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', publishing January 2008, (c) 2008 Pearson Education. Available on Rough Cuts at http://safari.informit.com/9780132302074

--
Edward L. Haletky
vExpert XIV: 2009-2023,
VMTN Community Moderator
vSphere Upgrade Saga: https://www.astroarch.com/blogs
GitHub Repo: https://github.com/Texiwill
Reply
0 Kudos