Low budget VMware capacity planning (part 1)

Today I started a research on options regarding capacity planning for an esxi deployment. Basically this project aims to virtualize ~30 physical servers.

First things first, I need to know whats the kind of load (cpu, mem, disk) I have globally. After that hopfully I will be able to size the hosts and begin the migration.
A chat with some esx ppl over #vmware follows:

[08:14am] MindTheGap: hello ppl. Im looking for metrics on how to plan an esx deployment, specially regarding client loads. Ok, I can measure network troughput, iops, MB/s but how do you size cpu requirements?
[08:14am] milestone: MindTheGap why not use the vmware capacity planner?
[08:14am] MindTheGap: I mean, a 20% load on a pentium4 means something completely different on a xeon
[08:20am] MindTheGap: i'm mostly calculating presentload/presentprocessorghz = X/futurecpughz where X would me the estimated load on the future processor but due to different architecture of newer processors, ghz also dont mean nothing.
[08:21am] MindTheGap: milestone, capacity planner is not free, at least the last time I looked up.
[08:22am] milestone: MindTheGap maybe it is worth the money... How bis is your setup?
[08:22am] MindTheGap: that would be presentload/presentprocessorghz = X/futurecpughz*numberofcores
[08:22am] twkm: empirical testing might prove useful to obtain your own ratios.
[08:22am] MindTheGap: milestone, not that big. something like 30 physical servers to be virtualized on a very tight budget.
[08:23am] twkm: ahh, good old very tight.
[08:23am] MindTheGap: :)
[08:23am] twkm: always enough money to have 30 servers, never enough to have 3 really good ones.
[08:23am] MindTheGap: tell me about it...
[08:24am] MindTheGap: its the fact of life of most Sysadmins
[08:24am] twkm: i like vmware's roi calculator. almost impossible to get it to present results for a transition.
[08:24am] johnt: capacity planner is only available for trained vmware partners at http://optimize.vmware.com/
[08:25am] johnt: MindTheGap perhaps you should calculate in Operations / Second
[08:26am] johnt: . /should/could/
[08:27am] MindTheGap: johnt, how should I do it? on a linux (to be)guest for instance?
[08:27am] twkm: that's the tricky bit, with today's processors, even with the p4.
[08:28am] twkm: put the known 20% p4 load on a proposed xeon (you can get an eval box, nyet?), and see what you get. tricky, but it can be instructive.
[08:29am] MindTheGap: johnt, I actually have not poked around /proc/ but I assume some statistics would be scattered there, yes?
[08:29am] twkm: esx, yes. esxi, no.
[08:29am] MindTheGap: twkm, sure, but Im trying to avoid it.
[08:29am] twkm: esx(i) is not linux.
[08:30am] MindTheGap: im talking about metrics, once i have it I can do it for the (would be)host as well
[08:30am] MindTheGap: and since the hosts have the same specs its ok
[08:30am] twkm: as you said, different cpu's. it won't be a constant.
[08:33am] MindTheGap: I got 3 maybe 4 hosts. all of them are Dell t410 with perc6i driving 2x 15k 500GB SAS, 8GB RAM and E5504 Nehalem procs.
[08:33am] twkm: if you are using esx for your eval you'd want to look at /proc/vmware/...
[08:35am] MindTheGap: i plan to use esxi on stand alone mode for now than maybe go for vsphere later on depending on the budget.
[08:36am] twkm: then you cannot see any stats on the host, and you'll have to get them via the api (e.g., in vsphere client).
[08:36am] MindTheGap: johnt, the operations/sec sounded good. can you elaborate on that please?
[08:37am] MindTheGap: im focusing on the guests now, then I will size the hosts and plan on how I will distribute the guests.
[08:40am] MindTheGap: twkm, I will measure the processor of the hosts while running linux on them, after taking 5% of esxi overhead maybe I will get a goot aproximation. well, I think
[08:40am] twkm: sounds like a starting point.
[08:45am] MindTheGap: so, just for the sake of clarity. there are no options for a "semi-professional" esxi deployment regarding to capacity planning, yes? either I do it by hand, creating my own metrics as I go or I will need to contact a vmware partner and give'em loads of money, is it correct? Dont take me wrong I'm not cheap I just dont have the money.
[08:46am] twkm: the not professional option is what you just got.
[08:46am] twkm: for the money spent you got the sort of results one would expect.
[08:47am] MindTheGap: twkm, oh, I very certain of that. but like I said, got no money but have to do it anyway.
[08:48am] MindTheGap: Actually it will be a good exercise. will make a post out of it. thanks everyone.
[08:49am] MindTheGap: I will start to hang out here more as I'm also preparing for my VCP next month, so I hope to chat w you all again. thanks twkm and johnt.
[08:50am] twkm: cpp;/
[08:50am] twkm: *boggle*
[08:50am] twkm: make that ... cool.

 

So, as I suspected, there are no options for a small scale deployment. Either you go for a full consulting with a VMware partner or you do it yourself.

Since some shops don’t have the money to spend on a full scale VMware solution, there is a gap between a low end deployment and a high end one.

Being so, I’ll move on with a diy aproach…

For the iops, mb/s and io contention I will use a very simple sampling of iostat output treated with awk resulting on a csv i can load on a spreadsheet.

Lets start with an awk script:


# Utilização: iostat -k N Y | awk -f iostat.awk > arquivodesaida.csv
# Exemplo: iostat -k 1 60 | awk -f iostat.awk > iostat.csv
BEGIN {
printf("%10s ;%10s ;%10s ;%10s ;%10s","CPU(Sy+Us)","I/O Wait","iops","kB_read/s","kB_wrtn/s")
}
(NF==6 && !/sda/ && !/evice/) {
printf("n%10s ;%10s ;", $1+$3, $4)
}
/sda/ {
printf ("%10s ;%10s ;%10s", $2, $3, $4)
}

This script gives me a nice output like this:

CPU(Sy+Us) ; I/O Wait ; iops ; kB_read/s ; kB_wrtn/s
16.55 ; 10.41 ; 195.29 ; 214.72 ; 516.47
0 ; 0.00 ; 0.00 ; 0.00 ; 0.00
0.25 ; 0.00 ; 0.00 ; 0.00 ; 0.00
0 ; 0.00 ; 0.00 ; 0.00 ; 0.00
0.5 ; 0.00 ; 0.00 ; 0.00 ; 0.00

to be continued…

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