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Archive for the ‘Microsoft’ Category

Moj prvý pokus o prezentáciu na ShowIT 2013

February 12th, 2014 No comments

Nech sa paci LINKA.

 

Categories: Microsoft, Windows Tags: ,

Moje prednášky pre ShowIT 2014

February 12th, 2014 No comments
Categories: Microsoft, Windows Tags: , , ,

Quickie: Exchang database migration over 24 hours

December 9th, 2013 No comments

Over the weekend I was setting up Exchange 2010 database copies using DAG. Those databases were huge (total of 3,5 TB). Line between primary and backup datacenter was 100Mbps. This migration ran over 24 hours for couple databases. When I checked the status I saw job was running 23 hours and 20 minutes:

When I have checked status in about hour and half I saw interesting time:

This happened on all databases which ran over 24 hours 🙂 So it looks like Microsoft engineers haven’t think about job running more than 24 hours 🙂

That’s all from weekend,

AVMA key in Hyper-V

November 26th, 2013 No comments

When you buy Windows Server 2012 R2 Datacenter edition you don’t have to activate every Windows Server 2012 virtual machine (Windows Server 2012 R2 Datacenter, Windows Server 2012 R2 Standard or Windows Server 2012 R2 Essentials.). There is new license key for Windows. It’s called Automatic Virtual Machine Activation (AVMA). You have to active Hyper-V host operating system. Then you use one of following AVMA keys for VMs on your Hyper-V hosts:

Datacenter Y4TGP-NPTV9-HTC2H-7MGQ3-DV4TW
Standard DBGBW-NPF86-BJVTX-K3WKJ-MTB6V
Essentials K2XGM-NMBT3-2R6Q8-WF2FK-P36R2

You use this keys using elevated command prompt on VM:

slmgr /ipk <AVMA_key>

When you do all of these steps all your Windows Server 2012 will be automatically activated. Even without  access of Internet from VM.

I hope something similar will be deployed on VMWare virtualization.

More oficial from Microsoft here.

Categories: Microsoft, Windows Tags:

Quickie: Nice utility to check DNS in AD

November 19th, 2013 No comments

Where there is a problem with AD replication, there is most of the time problem with DNS. Most of the time there are bad DNS records or missing DNS records. There is cool utility to check DNSLint.exe from Microsoft. It is designed to do all manual check I do when trying to solve AD replication problems.

You can download it from here and also read more about it.

It’s bad it’s not included into operating system by default.

Quickie: Delete all Offline files on Windows XP

November 19th, 2013 No comments

Couple days ago I migrated fileserver. We moved redirected My Documents for users on another server. We also hided these shares behind DFS namespace to make it more manageable in future. But we found out problem with this setup –  offline files. Windows XP kept offline copies of old and new redirected files. We had to clean this offline data database. I setup start up script:

@ECHO OFF
IF EXIST C:\OfflineFilesClean.txt (
  REM Do one thing
) ELSE (
  reg.exe add “HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\NetCache” /v FormatDatabase /t REG_DWORD /d 1 /f
  echo Vymazane > C:\OfflineFilesClean.txt
)

This script was dedicated just for Windows XP, so I had to apply GPO using WMI filter:

SELECT * FROM Win32_OperatingSystem WHERE Version LIKE “5.1%” and ProductType = “1”

This script would work also on Windows 7 and Windows 8, but those OS didn’t have problem.

That’s all for today,

Quickie: When you disable Data Decuplication you will lose Shadow Copies data

October 22nd, 2013 No comments

We had some problems with backup system backing up Windows Server 2012 deduplication enabled volumes. We decided to disable Data Deduplication on volume. After volume was converted back into “non data deduplication mode”, we found out that all Shadow Copies meta data was lost. It means all “Previous Versions” were lost. I really don’t see any reason to act like that, but there is probably some. It would be great if Windows warns you before you do the change. But it doesn’t 🙂

Have a nice day,

Internet Explorer 10.0 doesn’t get Proxy settings from Preferencies

October 17th, 2013 6 comments

I had weird problem today. Customer called that GPO I have created to set Proxy server for Internet Explorer doesn’t work anymore on Windows 7. He was right. There was Internet Explorer 10 installed on Windows 7. Proxy configuration was made by Internet Explorer Maintenance:

This was not applied on Windows 7 Internet Explore 10, even there was eventlog it should be applied. Then I set these settings using GPO Preferences. I could create settings just for IE 5,6,7 and 8:

I have decided to create settings using Internet Explorer 8. I set all settings I wanted and saved GPO:

Nothing happened. It’s because this settings are limited to Internet Explorer 8.0. So we need to dig into XML file which handles these settings. XML file InternetSettings.xml is located at \\DOMAIN\SYSVOL\DOMAIN\Policies\{76C1E5D1-9CA6-4682-AD41-FD038DDED1E9}\User\Preferences\InternetSettings. When you open this file you can see XML file with all settings. There is one attribute called MAX which defines on which version these settings are applied. I changed it to value “10.50.0.0” and now everything works:

What a stupid work around 🙂

Powershell script to change User Principal Name to Primary SMTP Address

October 2nd, 2013 No comments

When you install Exchange in environment you want to allow users to log into mails using their e-mail address. If your domain name is different from your e-mail domain, you have to add UPN suffix first. More abour it HERE. Then you need to change User Principal Name into Primary SMTP Address. I wrote little script to do so:

Get-Mailbox |
  ForEach-Object{
   Write-Host “For: ” + $_.SamAccountName
   Write-Host ”   – change UPN from: ” + $_.UserPrincipalName + ” to: ” + $_.PrimarySmtpAddress
   Set-ADUser -Identity $_.DistinguishedName -UserPrincipalName $_.PrimarySmtpAddress
 }

Have a nice day,

Categories: Exchange, Microsoft, Powershell Tags: ,

News in DHCP client since Windows 7

September 26th, 2013 No comments

Imagine you have DHCP server on network. You have all Windows XP and older clients. When DHCP server was not accessible on network during client’s startup, client computer couldn’t get IP address and it assigned APIPA address. This was a problem. So let’s look what’s new since Windows 7.

I prepared following scenario:

  • One DHCP server Windows Server 2012 – 192.168.0.10
  • One DHCP server Windows Server 2012 acting as default gateway – 192.168.0.11
  • One Windows 8 client – DHCP assigned
  • One Windows 7 client – DHCP assigned

When I client wants to get TCP/IP settings from DHCP server, there are four DHCP packets (DISCOVER, OFFER, REQUEST and ACK) going on network. Network dump on DHCP server:

This is normal behaviour even in old clients. Now I shutdown client and stop DHCP server. When I started client computer I found out that client computer has IP address it received from DHCP server before reboot.

So let’s restart client again and see what happends. Client computer has same TCP/IP settings, it had before reboot (TCP/IP settings received from DHCP server before I stopped DHCP server). Client computer keeps asking DHCP server to renew TCP/IP settings (using DHCP REQUEST):

So how client computer knows if it has to set cached TCP/IP settings before DHCP server stopped to respond? I assume it depends on gateway and its IP or MAC address. So let’s disconnect gateway from network and reboot client computer. Now client has APIPA TCP/IP settings and it looks for DHCP server by DHCP DISCOVERY:

It means it depends on health of gateway if client keeps TCP/IP settings assigned by DHCP or not. I haven’t seen any ICMP packet to check network healt of gateway so I assume it check MAC address. So let’s look for ARP packets from client to gateway. Looks like client asks for MAC address of saved default gateway IP address. When it received answer, it sets TCP/IP settings to cached TCP/IP settings:

Question is if client computer compares MAC address to some saved one or it just waits for ARP response and doesn’t care of MAC address. Let’s change MAC address of default gateway. Client keeps asking via ARP for MAC address. MAC address is different and client doesn’t set its saved TCP/IP settings (it sets APIPA settings):

So where client computer saves MAC address of default gateway?

Yes, in registry. 🙂 It’s saved under registry key:

and there are subkeys for each interface and under this key there is binary value called DhcpGatewayHardware which contains MAC address:

When client starts it checks for MAC address of its saved default gateway IP address. Then it compares to saved MAC address from registry. If these two MAC addresses don’t match, client deletes all saved TCP/IP settings from registries and uses APIPA (if there is not Alternate Configuration). In background it still looks for DHCP server by sending DHCP DISCOVER packets.

So now we have smaller problem on Mondays when DHCP server is down (of course by accident 🙂 ) and everyone is trying to get to network resources 🙂

I haven’t find any article about this new behaviour on oficial Microsoft websites.

That’s all folks,