Tips for creating multiple VM's (CPU, RAM, etc)

astrogeekastrogeek Member Posts: 251 ■■■□□□□□□□
I'm still pretty new with visualization but recently I added VMware workstation to my Cisco lab with the goal of being able to create a bunch of VMs to act as client PC's connected to my Cisco topology. The problem is I'm not really sure what the sweet spot is for creating a small enough VM that I can run a bunch of these at once, without each VM feeling too sluggish.

The equipment I'm using is a Dell PowerEdge 2850, two dual core 2.8Ghz processors with 4Gb of RAM. It's running Ubuntu 10.04 desktop (64-bit), version with VMware Workstation 8. I know I need more RAM, but I'm guessing 4Gb should be enough to at least run 3 or 4 Linux VMs at a time. One note about the Dell 2850 is that the CPUs can't run 64-bit virtual machines, but I'm only trying to create small VM's anyway so I don't think that should be an issue at this point.

Anybody have any tips on what would be a good sweet spot when creating these Linux VM's in the equipment I'm using?
How many CPU cores / threads should I give each VM? How much RAM?

Anybody have any recommendations for specific distributions of Linux that have a good GUI for a Linux noob like myself, while not being too bloated like some of the newer, more graphically heavy distros? Currently I've tried Ubuntu 10.04 and a couple versions of Linux Mint, but they still seem a bit sluggish and I'm only running one at a time, (plus the host system of course). Also, if the CPU's in this Dell are not too slow, how much more RAM should I upgrade to in order to start creating some Windows 7 VM's? I think it supports up to 16Gb, but would the CPUs even be fast enough?

Comments

  • odysseyeliteodysseyelite Member Posts: 504 ■■■■■□□□□□
    3-4 small linux vms are going to be the max for that configuration. Memory is going to be your bottleneck. You are ok with CPU. I would upgrade to 16GB ram. With that you could get some 32bit 2008 servers built and some Xp machines. Win 7 may not have enough resources if you are creating several vm's.

    I used XP because for basic connectivity, it only needs 1 cpu and 512mb-1gb of ram.
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  • AkaricloudAkaricloud Member Posts: 938
    Do you have a need to run an actual Linux distro or could you just run ESXi on it? -You'd be better utilizing your resources by running a bare-metal hypervisor instead.
  • kj0kj0 Member Posts: 767
    Second running ESXi. Run it from a spare tiny HDD on it's own or a USB stick (USB HDD even better) that way your Hard drives are dedicated to running the VMs.

    Like others have said, upgrade to 16GB, Win XP can run on as little as 64Mb, so 256/512 should be enough to get it running. Why not have a mixture of Win7 and XP? That way you get your Win7 boxes in there, but you have can double the amount of Vms you can have with Win7 machines in there. Good practice for Cross-versions of Windows type environment.
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  • meadITmeadIT Member Posts: 581 ■■■■□□□□□□
    If you're just going to use it to ping, etc from to test connectivity, check out Tiny Core Linux. Min RAM is 46 MB and recommended is 128 MB.
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  • mayhem87mayhem87 Member Posts: 73 ■■□□□□□□□□
    I would say maybe even try a cli only Linux vm if your just doing ping testing. Run esxi bare metal and just configure a switch for trunking the different vlans to the box. From there u can just make different port groups and assign those to the cli Linux. Put a ip on the boxes and bam ur done.
  • astrogeekastrogeek Member Posts: 251 ■■■□□□□□□□
    I had it setup for ESXi but the problem is ESXi doesn't support my Adaptec quad NIC cards, which I need for my GNS3 topology. This is why I'm running VMware Workstation instead, it gives me a bit more options. Basically I'd like each VM to be able to have its own NIC, (I have 13 available), which are then connected to four 3550 switches.

    When I create the VMs would it be better to give them each full access to all of the CPU and RAM, or set a specific amount, such as 2 cores + 512Mb of RAM? I'm thinking the latter is better, but even when I give them 2 cores + 1Gb of RAM they still feel pretty slow - but they are usable. I'll check out Tiny Core, but I think I'm also going to look into maxing out the RAM because I really want some Windows VMs :)

    Speaking of Windows, anybody know of good places to even get a copy of XP? Preferably a legit copy...Microsoft doesn't exactly make this easy!
  • blargoeblargoe Self-Described Huguenot NC, USAMember Posts: 4,174 ■■■■■■■■■□
    You gotta upgrade that RAM.

    I would start off each VM with just 1 core, and add more if you really need it... that is best practice. Memory I guess depends on which guest OS you're going to run. Make sure you get one of the supported Linux distros if you're going to run ESXi, so you can use VMware Tools and take advantage of memory ballooning.
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