Dales Diary
Musings of a sys admin
Windows 7 Minimum Requirements And Features
Jan 18th
Hi all,
Im starting to read my win 7 books now so will be putting up a few posts around my studying. The first blog post is about the minimum hardware requirements of windows 7 and also its features.
Firstly Windows 7 has 6 different editions which are: STARTER, HOME BASIC, HOME PREMIUM, PROFESSIONAL, ENTERPRISE, ULTIMATE.
The hardware requirements for 7 Starter and basic are as follows:
1Ghz x86 or x64 CPU
512MB’s of RAM
20GB hard disk (for x64 version) or 16GB hard disk for x86 version both must have 15GB free.
A graphics card that supports DX9 and has at least 32MB of Ram.
Windows 7 Home Premium and upwards requires:
1Ghz x64 or x86 CPU
1GB’s of RAM
40GB hard disk (15GB free)
A graphics card that supports DX9 and has a WDDM driver with pixel shader 2, 32bits per pixel and 128MB or RAM.
As always these minimum requires are of the OS only and you will find that Windows 7 will probably be usable but slow, adding applications will often make these systems too slow to use sensibly so you will need to install win7 in the real world on computers that are far better than the specs above.
Other hardware restrictions in windows 7 editions include support for up to 8GB or RAM in the x64 versions of Starter and Home Basic, whilst Home Premium is up to 16GB or RAM on x64 editions. All higher editions (Pro/Ent/Ult) are only limited by the x64 architecture which limits the RAM to 128GB (still if you get that in a laptop in the next few years your doing well).
The below table shows some of the major features of Windows 7 and which edition supports it.
| Starter | Home Basic | Home Premium | Professional | Enterprise/Ultimate | |
| Features | |||||
| Windows Aero | N | N | Y | Y | Y |
| DVD Playback | N | N | Y | Y | Y |
| Media Center | N | N | Y | Y | Y |
| IIS | N | N | Y | Y | Y |
| ICS | N | Y | Y | Y | Y |
| Join Domain | N | N | N | Y | Y |
| EFS | N | N | N | Y | Y |
| AppLocker | N | N | N | N | Y |
| Direct Access | N | N | N | N | Y |
| Bit Locker | N | N | N | N | Y |
| RDP | N | N | N | Y | Y |
| Branch Cache | N | N | N | N | Y |
Passed VCP 310
Jan 2nd
Hi all,
Well I passed my VCP exam back on the 11th December. Very pleased with that as it had only been announced a couple of weeks ago that the exam was retiring at the end of the year, So my studying suddenly increased 10 fold.
The exam itself seemed mostly fairly simple and the questions weto the point (not like the MS ones where they tell you about jane and dans breakfast routine before getting onto the NTFS issues).
I understand that the exam has also now been extended until the end of March 2010.
I think the next exam on my list will be the Windows 7 exam 70-680. After that perhaps a bit of Vsphere.
VirtualCenter 2.5 Min Hardware Requirements
Dec 7th
VC 2.5 requires at least:
2Ghz Cpu
2GB ram
560MB hard drive space
Network Card (pref 1Gb)
The OS needs to be Windows 2000 server with sp4 or Windows server 2003 with sp1 or Windows Server 2003 R2 edition.
Supported databases are:
Oracle 9i
Oracle 10g
SQL Express 2005 (ment for non production or low count farms)
SQL 2005 with sp1
SQL 2000 with sp4
Script to remove admin rights pt2
Nov 27th
Its been a while since I had a play with this script but what I have discovered is the software that I used to find out who has admin rights seems to also detect power users as Administrators. Which I guess is actually a good thing, however I did not suspect to get quite as many hits as I did for power users.
I’ll link all my old posts on the subject below so you can compare notes but the script that I have created now needs to include:
net localgroup “power users” %username% /delete > “%userprofile%\pwrusr.txt”
and
Y:\BLAT\BLAT %userprofile%\pwrusr.TXT -to email@address.com -server <smtp server IP> -f mail@address.com
Of course if you don’t want to be notified when these scripts run then you wont need the blat portion of the script and if you really don’t care about knowing if the initial check script has run then I guess you could just push out a script in the order of:
@echo off
c:
cd “%userprofile%”
If exist delusr1.txt (exit) else goto :Script
:Script
rem for removing admin Privileges
net localgroup administrators %username% /delete > %userprofile%\delusr1.txt
net localgroup “power users” %username% /delete > %userprofile%\pwrusr.txt
exit
This would then run regardless and attempt to remove the locally logged in user from power users and administrators groups. This would need to be assigned to just standard users though as you do not want to assign the script to administrators in your directory (be it AD, ED or maybe OpenLDAP).
Again this script is just the way I have chosen to do it, I am no expert in script writing (I really do need to figure out Vbscript), so I’m sure there are better ways of doing this.
Common ports for the 70-291 exam
Nov 16th
Hi all though I would do a quick post about common ports for the 291 exams, these ones would be very useful to memorize in case questions come up about them in the exam, (ip filtering etc I suppose may ask about them).
So here’s a small list of ports, I’m sure I will add to them as I read through my books, All ports are TCP unless otherwise specified.
FTP 20 and 21
HTTP 80
HTTPS 443
DNS UDP 53
SMTP 25
POP3 110
PPTP 1723
L2TP UDP 500 + 1701 + 4500
As you can see a lot of these ports you should already know from previous ms exams (client ones) so there’s not much else to memorize. But this may be a good starting point.
I would highly recommend creating your own list and printing them out and sticking them up in your office prior to taking the exam as it’s a great way of memorizing them (I used to do the same with min and recommended sys specs for the client and server exams).
TTFN
VMware High Availability
Nov 9th
High availability or HA as I will call it from now on, is a feature of Virtual Center which allows for the automatic restart of VM’s in the event of a host failure.
For example if you had 4 ESX servers running 40 VM’s (10 on each). if one host goes pop then HA would detect the failure and restart the VM’s on the 3 remaining hosts. However of course whilst there is not a great deal of options to fiddle about with (most of them follow the same pattern) you do have an important decision to make, which is if a host fails do you want to restart your VM’s or would you rather they stay down. This is basically is it more important that all the vm’s are up and running but possibly slower than normal, or would you rather some or all of the VM’s stay down until you have dragged yourself out of bed and into the office to fix the issue.
HA can be enabled once you have created a cluster by right clicking on the cluster and selecting “Edit Settings”. The first screen you will see consists of 2 check boxes, one for enabling/disabling HA and one for enabling/disabling DRS. The choice here is self-explanatory but you might want to spend a minute reading the couple of paragraphs on that page.
The next tab worth looking at is the Vmware HA tab there are 3-4 options here that you will need to consider.
The first option is Admission Control, within that setting is the options to set the number of host failures the cluster can tolerate this can be any number between 1-4. This by default is set to 2 and of course if you suddenly find yourself loosing 4 hosts in your cluster then you have a rather large problem on your hands. The next option is to prevent or allow the powering on of vm’s if they violate availability constraints. This means basically do you want to allow VM to be powered on even if the total number of configured memory resources exceeds the actual resources that the cluster provides.
Maths bit: You can work out your availability constraints by taking the amount of ram provided by your smallest ESX host (I.E, the one with the least amount of physical memory) and then find your vm with the most amount of configured memory and divide the ESX memory by the vm ram which will give you your figure of the amount of guest vm’s each host can have, any more than that and your availability constraints have been violated!
Example:
6 ESX Hosts smallest has 24 GB of ram largest amount of guest ram is 2GB and host failure is set to 1.
24/2×5=60
So if one host fails the total amount of virtual machines that can be powered on with violating availability constraints is 60. If you need any more than that then you will need to allow the vm’s to power on even though they violate the constraints.
The next setting is the default cluster setting, within the settings is the vm restart priority which is by default set to medium This setting is cluster wide but can be overridden at individual vm level. The configurable options for the restart policy are high, medium low and disabled. Clusters set to high have their vm’s restarted first, medium next and low last and disabled.. well you get the idea.
The next option down is the host isolation response setting, I’ve blogged about this before so I wont go into too much detail but it basically means when a host loses its network connection to other hosts in the cluster. Network connectivity is checked regularly by a heartbeat (ping). It is possible in vmware to have a situation where the host has lost its network connection to the other hosts in the cluster but the vm’s on that server are perfectly happy and working away normally. In previous updates of esx the default behaviour was to power off the vm which would leave HA to restart the vm’s on another server, However from U2 onwards this changed to leave vm powered on because you will find 9 times out of 10 just the service console is having issues and the vm’s are still working away quite happily.
The next option is “virtual machine monitoring” this again is an experimental feature which allows virtualcenter to monitor the tools installed on the vm’s (by using heartbeats in a very similar way to HA). You an enable this option and use the slider to adjust the sensitivity. Virtual machine monitoring does know when a vm has been purposefully shutdown or powered off so it will not be constantly restarting machines you are trying to shutdown.
The only button on this page is the Advanced Options which you should only make changes to this once you know what you are doing.
The sub tab of the HA options is “Virtual Machine Options” this allows you too specify different restart priority and host isolation response behaviours for individual vm’s. So you can effectively prioritize/delay or disable the restarting of individual vm’s should you deem appropriate.
Vmware common myths
Oct 28th
I think this is a post that i will keep updating as i think of things, but i thought i would start out with nice easy ones to get going with.
Something that quite often happens with a new esx farm is the admins want to tentively vm a ‘low risk’ server thinking that its not the end of the world if it goes skyward.
This normally translates as a server that does not do much and has been sat in the corner of the server room for years banging away doing its thing. Now of course when its virtualized its given a whole new set of hardware that is years away from what its used too. This gets admins and users very excited as whatever that server used to do is now been given a massive boost in performance.
Virtualization is not about speed its about consolidation. As admins start virtualizing other boxes the old server may very well go back to about the speed it was before.
More to follow
VMware NTP Weirdness
Oct 26th
Well today I discovered that one of the ESX hosts in our cluster did not have its NTP settings correctly configured, although it did take me a little while to figure it out.
We have a 2003 guest box on the host which when I logged onto it to do some work was displaying a totally wrong date and time. So I set it back manually in the OS (we dont use DHCP for our server subnet). Did not think much of it until 10 minutes later all of a sudden the correct date and time reverted back to the wrong date and time. I checked the 2003 boxes settings again and it wasnt synching its time with any internet NTP server which is how we like it. So I had a look at the vmware tools installed on the box and sure enough that was not set to synch time with the host so again I ruled that out.
So I merrily set the date and time again and went on my way and sure enough in another 10 minutes the date/time had reverted. so I checked the host and found that NTP was not enabled and was displaying the same date and time as the 2003 guest OS. I set up NTP on the host and this cured the issue.
I do find it somewhat strange that even though the guest was not set to sync date/time with the host it still did it, presumably after the w32 service failed to sync with an online ntp service the VMware tools took over and synched it anyway.
Weird, I feel a bit of googling coming on!
Ramping up
Oct 21st
Well I’m now starting to think about ramping up my vmware studying due to the oncoming 1st attempt at the exam. I do feel a bit more relaxed about it than previous exams, probably because I administer esx/vc loads at work but of course that doesnt mean I can take it easy. I’ve rebuilt my ESX lab at home using the eval versions of esx and VC I downloaded a while back. The only thing I had to re-register was for another evaluation version of VMware Workstation, otherwise I just used the ISO’s I had previously downloaded.
Anyway As I am studying and doing test’s I shall put up various musings on my way.
On a side note because I do not have a great deal of linux knowledge I am having quite a few problems virtualizing exisiting linux boxes. I am bookmarking interesting links to do with virtualization (methods including rsync etc), but so far have only managed to virtualize one linux box without too much trouble. This is kinda spurring me on to learn loads more linux stuff.
Transcender sale 20-21 oct 2009
Oct 20th
I have just had an email come in saying that transcender are have a 40% off sale on all their items for 2 days only.
You may remember that I reviewed a transcender product not too long ago and it came out very well against the product I had normally used. So if you have not used transcender yet now is a good time to give them a go.
www.transcender.com