teknoglot: « Page 3

Installing Linux Integration Services v2.1 on Red Hat ES 5

Posted on August 31, 2010 by Sam T

Ok, so I got the task to install the Linux Integration Service for Hyper-V R2 on a RedHat Enterprise Server 5. Something that turned out to be a bit more to handle than I would have thought. So here’s a little How-To.

Preparations

Read the documentation provided in the Linux Integration Services download. Much of the information in this article is in there, but some parts are not. Otherwise I would not have bothered writing about it.

I’m not going to go through the OS installation process here, but make sure to select the “Software Development” packages since you will be needing it. In case you missed it, you can install them later by running these commands.

# yum groupinstall "Development Tools"
# yum install kernel-headers

I’m not actually sure that you need to run the kernel-headers install manually or if it’s included in the “Development Tools” package.

The first gotcha i ran into was the fact that the link to the Linux Integration Services–previously known as Linux Integration Components or LinuxIC–on RedHat’s information pages gave me a 404 and a redirect to a bing-search that returned the exact same 404. The page have simply been removed by Microsoft without any form of redirection to the new page. Anyway, a search on http://download.microsoft.com for “Linux Integration Components” do return the new page, and that’s where I learned about the new name.
Thank you for making it easy for us Microsoft!
Here’s a direct link to the search on the current name: http://www.microsoft.com/downloads/en/results.aspx?freetext=linux+integration+services&displaylang=en&stype=s_basic
And here’s a direct link to the actual download page: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=eee39325-898b-4522-9b4c-f4b5b9b64551

This download contains an ISO file that you can mount using the Hyper-V- or VMM-console, or you can do as I did and download the ISO to the virtual machine, mount it locally, copy the files and unmount it. Like this.

# mkdir /mnt/ISO
# mount -o loop /root/LinuxIC v21.iso /mnt/ISO
# mkdir /opt/linux_ic_v21_rtm
# cp /mnt/ISO/* -R /opt/linux_ic_v21_rtm/
# umount /mnt/ISO

You probably have to be root to do this by the way.
With that done, let’s get to the installation.

Installation

As root, do the following:

# export PATH=$PATH:/sbin
# cd /opt/linux_ic_v21_rtm/
# make
# make install
# reboot

Why the export PATH command? Apparently, on RHES5, /sbin is not in the PATH by default and this is something that the make scripts are completely unaware of. The “make install” will try to run “depmod” which will fail since it’s not in the default path. You could also add “PATH=$PATH/sbin” to the root users ~/.bashrc which will put it back in the PATH but only for the root user, but I don’t know if that’s recommended.
And, yes. You DO have to reboot after the install.

If you are running RHES5 64bit you also have to install the “adjtimex” package. It is in the RHN repository but also on the RHES5 Installation CD in case you have no internet connection. Install it with yum like this:

# yum install adjtimex

And from the CD (mount it first) like this:

# rpm –ivh /mnt/cdrom/Server/adjtimex-1.20-2.1.x86_64.rpm

And that’s basically it for the installation.

Verification

How do you know that the driver are installed?

After the reboot, try running “modinfo vmbus” which should return something like this:

# modinfo vmbus
filename:       /lib/modules/2.6.18-194.11.1.el5/kernel/drivers/vmbus/vmbus.ko
version:        2.1.25
license:        GPL
srcversion:     3C1899C419665CB2514F2D0
depends:
vermagic:       2.6.18-194.11.1.el5 SMP mod_unload gcc-4.1
parm:           vmbus_irq:int
parm:           vmbus_loglevel:int

Try that with netvsc, storvsc and blkvsc too (replace the vmbus part) and you should get something similar. If you don’t, the installation did not succeed.
The documentation also tells us to check that the components are running with “/sbin/lsmod | grep vsc” which should return:

# /sbin/lsmod | grep vsc
blkvsc                 70184  3
storvsc                64264  0
netvsc                 73504  0
vmbus                  88304  3 blkvsc,storvsc,netvsc
scsi_mod              196953  6 scsi_dh,sg,blkvsc,storvsc,libata,sd_mod

The numbers will probably differ from installation to installation depending on blocksizes and allocation.

Configuration

Configuration is pretty straight-forward so I’ll keep this short.

When you install the drivers you will get a new network card called seth0, which I presume stands for Synthetic ETHernet. There’s nothing magic about it regarding configuration and “system-configuration-network” will work just fine.

The drivers will also give you a couple of SCSI-devices (if you have one attached) with the regular /dev/sd* naming. Simply configure these using fdisk or whatever GUI you might prefer.

There is also a note in the documentation about changing the grub configuration in the “Additional Information…” section. Do read that section.

Additional Comments

One thing I tend to do now that disk space is dirt cheap is to copy all ISO-files I use locally instead of mounting them when needed through Hyper-V. Simply because you can bet your insert-shorter-word-for-buttocks that the day you need it again, someone has been kind enough to have done som spring-cleaning or it’s locked by another machine in the cluster. If you have it locally and followed my instructions in the “Preparation” section, you will allready have a /mnt/ISO directory. Only thing you’ll have to do is

# mount -o loop /path/to/your.iso /mnt/ISO

And there you have it. Just remember to unmount it when you’re done.

I also almost never use the Hyper-V remote connection interface thingy since it will give you a GUI and the mouse just won’t work. If you haven’t configured a network card yet though, you could connect through Hyper-V and hit Ctrl+Alt+F1 to get a command prompt. Unfortunatly cut/paste don’t work here, but you could run system-configuration-network, assign an IP-address and then connect with an SSH client. I prefer PuTTY to a degree that I usually install the ported version on my Linux desktops aswell.

And I never logon using root. People should know this, but it should be stressed anyway. Always logon as regular user and su or sudo when needed. I can’t understand why RHES has root-login enabled by default in the SSH-server config.

Good luck!

Categories: Hyper-V, RedHat ES | Tags: How-To, Hyper-V, Linux, RedHat, RHES5

“Load Balancing” Powershell Script for Operations Manager

Posted on April 15, 2010 by Sam T

3 Comments

I’ve been looking for at way to evenly distribute agents between Gateway Servers (or Management Servers for that matter, but I’ll stick to GWs this time) for some time but haven’t really got to fixing it myself until now.

The situation is basically that we’re monitoring customers through gateway servers connected to our central Operations Manager environment. To have a bit of redundancy we always put two (or more) gateway servers per site (or customer, really) and they, in turn, talks to a couple of central management servers. I guess a drawing would be nice, but I have no Visio on this computer. The gateways are manually configured to talk to different management servers and have the others configured for fail-over (through powershell) and since we’re talking about no more than a few handfuls (say 20-ish) it’s not a problem handling it that way.

Agents, on the other hand, are a different matter. Even though we try to spread them out somewhat evenly at deployment between the gateway servers at each site we still end up looking at a 3:2 ratio after a while and since agents do not automatically fail-over between gateway servers we need a way to fix that too.
So I wrote a little powershell script that takes a bunch of gateway servers (or management servers) as parameters, gathers all connected agents, spreads the agents evenly between the servers and configures the others as fail-over servers while at it.

It’s all pretty crude, but it works and you can download it from here: DistributeAgents.ps1
Save it somewhere on disk and call it from the Operations Manager Shell like this:

C:DistributeAgents.ps1 gateway01.customer.local,gateway02.customer.local,gateway03.customer.local

Yes, you should replace “C:” with whatever path you decided to save the script to and “gatewayXX.customer.local” with a real servername.

Ok, I’m a powershell freshman and I’m pretty sure you could do this a prettier way, but here’s the script:

Param([array]$CSVServerList)

$arrServerObject = @()
$arrAgentObject = @()

foreach($Server in $CSVServerList)
{
	$arrServerObject += Get-ManagementServer | where {$_.Name -eq $Server}
	echo "Looking for $Server"
}
$ServerCount = $arrServerObject.Count
if ($ServerCount -gt 1)
{
	echo "Found $ServerCount management servers"
} else {
	echo "Found only 1 (or less) management servers. Aborting..."
	Exit
}

echo "Getting agents..."
foreach ($Server in $arrServerObject)
{
	$arrAgentObject += Get-Agent | where {$_.PrimaryManagementServerName -eq $Server.Name}
}
$AgentCount = $arrAgentObject.Count
if ($AgentCount -gt 1)
{
	echo "Found $AgentCount agents"
	Start-Sleep -m 200
} else {
	echo "Found only 1 (or less) agents. Aborting..."
	Exit
}
$i = 0
foreach ($Agent in $arrAgentObject)
{
	if ($i -ge $ServerCount)
	{
		$i = 0
	}
	$arrTemp = @($arrServerObject | Where-Object {$_ -ne $arrServerObject[$i]})
	# $FailoverServers = $arrTemp -join ","
	Set-ManagementServer -AgentManagedComputer: $Agent -PrimaryManagementServer: $arrServerObject[$i] -FailoverServer: $arrTemp

	$arrTemp = $null
	$i++
}

I have used it on a couple of occasions now and have only discovered a problem with an error when one of the servers don’t have any agents at all (probably a new one), but the script still works so I haven’t really dived into it.
Now, as with all scripts you download on the ‘net it’s up to you to test it in a lab before shooting wildly among your in-production systems. I really can’t give any warranties that it won’t FSU royally at your place.

Categories: OpsMgr 2007, PowerShell | Tags: OpsMgr, PowerShell, Script

MSMQ 4 and MSMQ 5 MP for OpsMgr Released! (finally)

Posted on April 6, 2010 by Sam T

2 Comments

After a long wait (definitely more than 90 days) the management packs for MSMQ 4 (Windows 2008) and MSMQ 5 (Windows 2008 R2) are finally released.

Both seem to be fully Cluster aware and pretty much holds the same monitoring as the the latest MSMQ 3 MP.

Message Queuing 4.0 Management Pack for Operations Manager 2007

Quick Details

Version: 6.0.6700.83

Date Published: 4/5/2010

Language: English

Download here: http://www.microsoft.com/downloads/details.aspx?FamilyID=cfc103b8-7185-4721-8098-110885fe9e9e&displaylang=en

Message Queuing 5.0 Management Pack for Operations Manager 2007

Quick Details

Version: 6.0.6700.88

Date Published: 4/5/2010

Language: English

Download here: http://www.microsoft.com/downloads/details.aspx?FamilyID=28349b78-8329-44aa-8a1f-81f4e3f84d0c&displaylang=en

Categories: OpsMgr 2007 | Tags: Management Pack, MSMQ

Change Gateway Powershell Script

Posted on March 31, 2010 by Sam T

No Comments

This script has pretty much already been covered in my previous post about Changing or Replacing an Operations Manager Gateway Server.

This time I’ve basically put parameter support in it to make it easier to use.

Here’s the script anyway.


Param($OldGW,$NewGW)

$OldMS= Get-ManagementServer | where {$_.Name -eq $OldGW}
$NewMS = Get-ManagementServer | where {$_.Name -eq $NewGW}
$agents = Get-Agent | where {$_.PrimaryManagementServerName -eq $OldGW}
$agents = $agents
"Moving " + $agents.count + " agents from " + $OldMS.Name + " to " + $NewMS.Name
Start-Sleep -m 200
Set-ManagementServer -AgentManagedComputer: $agents -PrimaryManagementServer: $NewMS -FailoverServer: $OldMS

To use it, create a textfile called ChangeGW.ps1 and paste the code into it. Save the file somewhere neat (maybe C:Scripts) for easy access. If you don’t feel like copy/pasting, you can download the script here.

To use it, open the Operations Manager Command Shell and type:
C:ScriptsChangeGW.ps1 <old.gatewayserver.dns.name> <new.gatewayserver.dns.name>

For example:

C:ScriptsChangeGW.ps1 gwserver01.domainname.local gwserver02.domainname.local

Categories: OpsMgr 2007, PowerShell | Tags: OpsMgr, PowerShell, Script

ESENT Error When Modifying OpsMgr Agent

Posted on March 19, 2010 by Sam T

No Comments

Getting “ESENT Kerys are required to install this application” when you are trying to modify/change an agent installation?

This seems to be most common on Windows 2008 and i guess it’s because of the UAC and the fact that opening the Control Panel isn’t running in administrative mode.

To work around this you need to run the msiexec command on the correct installation GUID from an administrative command prompt.

Besides running through the registry to find the GUID, one of the easier ways is this:

Open an administrative command prompt.
run wmic product
Locate your product by its name, the GUID (looks a bit like this {25097770-2B1F-49F6-AB9D-1C708B96262A}) directly after that is the one you want. Copy it.
run msiexec /i <PASTEYOURGUIDHERE>
Modify the agent as pleased

That’s pretty much it. Good luck.

Categories: OpsMgr 2007 | Tags: Errors, How-To, OpsMgr, Windows, Windows Installer, WMI

Updated MSMQ Management Pack v6.0.6615.0!

Posted on December 23, 2009 by Sam T

No Comments

Microsoft has released an update to the MSMQ (version 3) management pack.

System Center Pack for: Message Queuing 3.0
Version: 6.0.6615.0
Released on: 12/14/2009

Message Queuing (also known as MSMQ) is a server application that enables applications to communicate across heterogeneous networks and systems that may be temporarily offline or otherwise inaccessible. Instead of an application communicating with a service on another computer, it sends its information to Message Queuing, which sends the information to a Message Queuing service on the target computer where it is made available to the other application. Message Queuing provides guaranteed delivery, efficient routing, security, and priority based messaging.

Now, what’s really interesting is what you will find in the MP Guide under “Supported Configurations”.

The Message Queuing Management Pack for Operations Manager 2007 is designed to monitor Message Queuing version 3 only.

The Message Queuing Management Pack supports the following platforms:

· Windows Server 2003

· Windows XP

The Message Queuing Management Pack also supports monitoring clustered MSMQ components.

Text coloration is obviously added by me to highlight the interesting part.

Finally MSMQ monitoring seems to be cluster aware, which might mean that the home-made pack i did to have those (numerous) queues covered could be passed on to the scrap-heap. This is also confirmed under “Changes in This Update”.

The December 2009 update to this management pack includes the following change:

· Fixed a problem when working with an instance of MSMQ in a Cluster. The MP is now able to discover and monitor public and private queues in a cluster.

· Fixed a problem when discovering the local and cluster instance of MSMQ. The MP is now able to discover and monitor both instances.

The confusing double RunAs profiles seems to have been cleaned up too (you only have to worry about one now) as well as fixing some sloppy mistakes in the previous scripts (no Option Explicit? C’mon Microsoft! You write the best practices, try to stick to them.) and generally improving display and documentation.

Gonna import this to our staging environment today and let it roll during the holidays.

Cheers! Oh, and happy holidays!

Download and documentation:
http://www.microsoft.com/downloads/details.aspx?FamilyId=1D2B4398-8BC2-4A43-850C-852EBB0D983B&displaylang=en&displaylang=en

Categories: OpsMgr 2007 | Tags: Management Pack, MSMQ, OpsMgr

Linux Discovery – Not Enough Entropy

Posted on December 2, 2009 by Sam T

3 Comments

Here’s a little trouble-shooting guide for discovering Linux systems from OpsMgr R2 when getting the following error from the wizard:

<stdout>Generating certificate with hostname="COMPUTERNAME"

[/home/serviceb/TfsCoreWrkSpcRedhat/source/code/tools/scx_ssl_config/scxsslcert.cpp:198]

Failed to allocate resource of type random data: Failed to get random data - not enough entropy

</stdout><stderr>error: %post(scx-1.0.4-248.i386) scriptlet failed, exit status 1

</stderr><returnCode>1</returnCode>

<DataItem type="Microsoft.SSH.SSHCommandData" time="2009-08-05T11:15:01.5800358-04:00" sourceHealthServiceId="0EB1D6DA-202C-7FC5-3D46-BDBB9208547D"><SSHCommandData><stdout>Generating certificate with hostname="COMPUTERNAME"

[/home/serviceb/TfsCoreWrkSpcRedhat/source/code/tools/scx_ssl_config/scxsslcert.cpp:198]

Failed to allocate resource of type random data: Failed to get random data - not enough entropy

</stdout><stderr>error: %post(scx-1.0.4-248.i386) scriptlet failed, exit status 1

</stderr><returnCode>1</returnCode></SSHCommandData></DataItem>

But first, a little background on the actual “problem”. To generate the certificate, the entropy needs to be high enough to generate random data for the certificate creation. Without the certificate, the OpsMgr agent won’t be able to open up communications with the MS. So, what creates this entropy we need? Bluntly put, a selection of hardware components that are likely to produce non-predictable data. Like a keyboard, mouse and a monitor or videocard. Of course, there’s a lot more to it, but we really don’t need to know this. What we need to know is that there has to be a “bit bucket” of more than 256bytes of entropy for the certificate creation process to succeed. We also need to know that more enterprise-ish servers, like rack- or blade-servers tend to be void of things like directly attached keyboards, mouses and monitors that the linux kernel needs to be able to generate entropy. And herein lies the problem. If you have a new server that is not in full service (likely since we are trying to deploy the monitoring on it) which means that there’s not much random data flowing through the hardware and there’s no keyboard or mouse or monitor connected to it there is quite the risk that the system entropy is going to be very low. Of the linux systems that I have been deploying OpsMgr agents to, about half have failed because of “Not enough entropy”. So, here’s the steps I usually takes to ensure that discovery works. I use PuTTY to connect to the soon-to-be-monitored servers. This guide also assumes that you have SU rights on the system since all of these steps (except #1) needs it.

Check you current entropy
```
cat /proc/sys/kernel/random/entropy_avail
```
Is it less than, or close to, 256? It probably is. If you don’t feel like connecting a mouse and start wiggling it around—not really feasible in a data center—and see if the entropy increases, you can generate your own random data.
Generate you own random data.
Be advised that this forced entropy will not be as random as the system-created on and thus not as secure. How much more insecure it is, I don’t know, and quite frankly I prefer to have my systems monitored yet slightly less secure than not monitored at all. Anyway, you can force your own random data by running:
```
dd if=/dev/urandom of=~/.rnd bs=1 count=1024
```
This creates a .rnd file with 1024B of random data that the certificate creation process will use instead of the system entropy if the file exists.
Uninstall and re-discover
The first failed attempt of discovery will most likely leave a non-working agent installation that we have to remove. Otherwise we will just be stuck with an “Access Denied” error. Run:
```
rpm –e scx
```
Now, try to discover the system again.

Failed again?
Try generating the certificate manually by running:

/opt/microsoft/scx/bin/tools/scxsslconfig -f –v
/opt/microsoft/scx/bin/tools/scxadmin –restart

Retry discovery again.

Still fails?
Uninstall the agent once more as instructed in step 3.

Stese steps have solved my problems 100% on both SUSE and RedHat and hopefully they will help you too.

Interestingely enough, these problems seems to be connected to some changes in the 2.6 kernel and basically everything that uses SSL-ish certificates will be affected. Even though the symptoms may be a bit more subtle, like time-outs and disconnects. For “headless” servers like those I usually to administer where the random data tend to be much lower, there’s even specialised hardware whose sole purpose is to generate random data, like the Entropy Key. I have also been told that new servers is likely to be equipped with entropy chipsets to make sure that there’s chaos enough to avoid these new-found oddities.

Sources:
http://social.technet.microsoft.com/Forums/en-US/crossplatformsles/thread/f94ec905-23ac-4444-b9f8-644fec3ae357

http://www.askrenzo.com/oracle/SCOM/SCOM_discovering_nodes.html

Categories: OpsMgr 2007, SLES | Tags: How-To, Linux, OpsMgr, TroubleShooting, X-Plat

Installing Linux Integration Services v2.1 on Red Hat ES 5

Preparations

Installation

Verification

Configuration

Additional Comments

“Load Balancing” Powershell Script for Operations Manager

MSMQ 4 and MSMQ 5 MP for OpsMgr Released! (finally)

Message Queuing 4.0 Management Pack for Operations Manager 2007

Message Queuing 5.0 Management Pack for Operations Manager 2007

Change Gateway Powershell Script

ESENT Error When Modifying OpsMgr Agent

Updated MSMQ Management Pack v6.0.6615.0!

Linux Discovery – Not Enough Entropy

kaTWEET!

Categories

Recent Posts

Recent Comments