Lio-Target Python Errors CentOS 6.x

 iSCSI, Linux  No Responses »
Jun 062012
 

So, as most of you know, I have TONS of articles pertaining to getting Lio-Target running on Cent OS. In the beginning, things seemed rather “hit or miss” due to weird errors when either building lio-target or lio-utils…

Turns out, most of the issues I’ve had are related to Python and the current running version. Recently I updated one of my storage boxes using yum, and it completely broke Lio-Target, and Lio-Utils when I had to rebuild them for the new kernel. I was in a panic to mount an old CentOS 6 ISO to get one of the first Python version for CentOS. After downgrading, I was able to build and install both.

 

Just a heads up for you people getting weird python errors.

How To and Guide (Updated): Get Lio-Target running on CentOS 6

 iSCSI, Linux, Storage, VMware, vSphere  46 Responses »
Oct 142011
 

In this tutorial, I will be showing you how to get Lio-Target (an iSCSI target that is compatible with persistent reservations required by both VMware and MS Clustering) running on CentOS 6.

While this tutorial is targetted for CentOS 6 users, I see no reason why this should work on any other newer distributions.

Please note that while Lio-Target 4.x (and required tcm_loop and iSCSI) is available on newer/non-stable development kernels, Lio 3.X is stable, and currently builds nicely on CentOS 6. I will be doing up a tutorial for Lio 4.X once I myself start using it.

One more note, In the past I have thrown up a few tutorials on how to get Lio-Target running on various Linux distributions. These tutorials have worked for some, and not for others. I myself have had a few difficulties replicating the success I did originally. I myself am a technical guy, I do not understand some developer terms, and am not an expert in understanding some development cycles. This is one of the reasons why I had so many difficulties earlier. Since the earlier tutorials, I have caught up to speed and am familiar with what is required to get Lio-Target running.

Now on to the tutorial:

It is a good idea to start with a fresh install of CentOS 6. Make sure you do not have any of the iSCSI target packages installed that ship with CentOS. In my case I had to remove a package called something like “iSCSI-Target-utils” (This shipped with the CentOS 6 install).

1. Let’s download the software. We need to download both the 3.5 version of Lio-Target, along with Lio-utils which was built for 3.x of Lio-Target. (I chose the RisingTide Systems GIT repo since lio related projects have been missing from kernel.org’s GIT repo due to the issues kernel.org has been having recently).

Issue the following commands:

git clone git://risingtidesystems.com/lio-core-backports.git lio-core-backports.git

git clone git://risingtidesystems.com/lio-utils.git lio-utils.git

cd lio-utils.git/

git checkout --track -b lio-3.5 origin/lio-3.5

cd ..

(You have now downloaded both Lio-Target 3.5 backport, and lio-utils for lio-target 3.x)

2. Build kernel modules for your existing running CentOS kernel. Make sure you change in to the lio-core-backports directory first.

Change in to the lio-core-backports directory then issue the following commands:

make

make install

(You have now built, and installed the kernel modules for Lio-Target)

3. Build lio-utils and install. This is one of the tasks I had difficulties with, for some reason the install scripts were calling out to the incorrect python directory, I found a fix to this myself.

Apply the fix first:

Go into the tcm-py and lio-py directories inside of the lio-utils directory. Open the install.sh in both the tcm-py and lio-py directories and change the “SITE_PACKAGES” string to reflect the following:

SITE_PACKAGES=/usr/lib/python2.6/site-packages

Remember to do this in both the install.sh files for lio-py and tcm-py. Now on to building and installing lio-utils.

Issue the following commands from the lio-utils directory:

make

make install

And you are now done!

Lio-Target and Lio-Utils have no succesfully been installed. As you can see, this was way easier than my previous tutorials, and doesn’t include and rebuilding of kernels, etc… One of the plus’s is that you actually build the kernel modules for the existing CentOS kernel.

One last thing. Start lio-target by issuing the command:

/etc/init.d/target start

And do a ‘dmesg’ to confirm that it started ok!

As always, feel free to post any comments or questions. I’ll do my best to help!

Microsoft iSCSI Target Software – First Impressions

 iSCSI, Microsoft  No Responses »
Apr 222011
 

Well,

I finally got some time to tinker with the Microsoft iSCSI Target Software that as of recently is now free. I was surprised how easy it was to get this up and running.

First time, it literally took 30 seconds for the install, and with absolutely no experience I created, configured, and setup a 80GB target and mounted it to a Windows 7 initiator. Took me approx an additional 15 seconds to learn how to snapshot volumes, etc…

The interface for configuration is very light, clear, and non-confusing. I was almost surprised there wasn’t more, but at the same time in all reality there’s nothing else to put on there.

Next plan: Get this running on a physical box and test VMware ESXi hosts connecting to it in a clustered environment. I’ll keep you guys posted!

Microsoft iSCSI Target Software is now free!

 ESXi, iSCSI, Microsoft, Storage, VMware, vSphere  No Responses »
Apr 152011
 

I thought I’d pass this on to all you iSCSI enthusiasts out there!

This morning I received an e-mail forwarded on by someone.

Apparently the Microsoft iSCSI Target Software is now free and runs on Windows Server 2008 R2.

Article:

http://blogs.technet.com/b/canitpro/archive/2011/04/05/the-microsoft-iscsi-software-target-is-now-free.aspx

I plan on getting this installed, setup, and configured sometime in the next couple weeks to test with my VMware vSphere environment. I’ll post my results 🙂 Happy SANing!

Update: vSphere and Lio-Target – My Setup and Configuration

 ESXi, iSCSI, Linux, VMware, vSphere  27 Responses »
Jan 102011
 

I notice quite a bit of traffic coming in (alot of it is the same people coming back) searching for information on VMware vSphere using iSCSI, specifically Lio-Target (because of the compatibility with SCSI persistant reservations).

In the past I’ve been jumping all over the place testing Lio-Target on different distrobutions, test scenarios, etc… I’ve officially implemented it into my production network and just wanted to report it’s been running solid for a few months now.

Current Working Configuration (Stable):

Currently at the moment I have numerous HP Servers (ML350s, DL360s) running ESXi off an internal usb-key. These ESXi hosts are accesing numerous iSCSI targets over gigabit hosted on a DL360 G6 with 2 X MSA20 storage units. The server hosting the storage is running Ubuntu 10.10 and has been rock solid with absolutely no issues. I’m fully utilizing VMotion amongst all the hosts, and all hosts have concurrent access to the iSCSI targets. This is running in full production and I’m fully confident in the configuration and setup.

Future Plans:

Lio-Target is going upstream in to the Linux kernel on the next release (2.6.38). With the testing I did (and blogged about) in the past months, I have not been able to get the newer versions of Lio-target running stable on CentOS. Once a new version of CentOS is released, or there is a kernel upgrade available to bring CentOS to 2.6.38, I will be installing CentOS on to the storage server and adding more disk space. Once this change is complete, that will conclude any future changes for a while (excluding adding more ESXi hosts).

If anyone has any questions on my setup, or configuration with something similar, or have any issues with Lio-Target, please feel free to leave a comment and I’ll see if I can help!

Plans to install Lio-target on a Soekris Net4801

 iSCSI, Linux, net4801, SBC (Single Board Computer), Soekris, Storage  8 Responses »
Oct 202010
 

Well, my Ubuntu Server box running Lio-Target is still running great, and performing perfectly under the continous stress testing I’ve done.

While I’m waiting for a few more days of the stress test to finish, I’m setting up my old Soekris Net4801.

I’m install Ubuntu Server 10.04 TLS on to the Soekris Net4801 via remote PXE netboot. Afterwards I’m going to compile Lio-target 3.4 (kernel 2.6.34) on the device and test out performance of the iSCSI target. It won’t be anything special since the net4801 is so slow, but it’ll be interesting to see for sure.

I’ll also be sticking in a PCI – USB2.0 card inside of the net4801 to get USB2.0 speeds on a removal drive.

After this little experiment I might rip out the cross compiler and build Lio-Target on a Linksys WRT610N if I can to check out the performance on that. I know these little devices have quite a bit of power, gigabit networking, and a single USB 2.0 port built right in!

As promised I’ll be posting more detailed posts in the future once all the fun is done!

Some notes on Lio_target on CentOS

 iSCSI  10 Responses »
Oct 192010
 

So here’s the deelio…

Both Lio-target 3.2, 3.4, and 4.0rc always end up causing a CPU stall on CentOS within 6 hours of a single ESXi host using it. I could get it to bug out quicker while performing heavy usage.

Right now I’m testing it out on Ubuntu, it’s already looking more stable.

If anyone knows why it’s soo buggy on CentOS, PLEASE leave a comment, I’d really like to get it running.

Also had a bunch of problems compiling lio-utils both on CentOS and Ubuntu. If you use git, and install 3.0 it will install on CentOS, then u can install the newer version after. However installing the latest stable doesn’t work, comes up with a bunch of errors.

I’ll be posting another blog entry in regards to running Lio_Target on Ubuntu 10.10 within the week!

Update:

PLEASE VISIT http://www.stephenwagner.com/?p=300 for an updated tutorial on how to get Lio-Target running stable on CentOS 6!

Configuration of a vSphere 4 multiple ESXi host configuration with open source iSCSI target (lio-target)

 ESXi, iSCSI, Storage, VMware, vSphere  No Responses »
Oct 082010
 

Just got my test network setup:

  1. HP Proliant ML350 G5 – Running ESXi
  2. HP Proliant DL360 G5 – Running ESXi
  3. HP Proliant DL360 G5 – Running ESXi
  4. Custom Intel Server – Running vSphere (management server)
  5. Super Micro Server – Running CentOS 5.5 with lio-target (iSCSI Target)
  6. 2 X HP MSA20 – Running Multiple Arrays/Targets connected to Super Micro Server

The HP servers are booting ESXi via USB keys. The Super Micro Server has one single internal drive for OS, and connected to multiple MSA20 arrays acting as iSCSI targets. The custom intel server is running the vSphere vCenter Management software.

I’ve Storage vMotion’ed multiple test VMs to the iSCSI arrays. Currently testing! Speed is AMAZING! And judging from the logs on the Super Micro Server, the iSCSI SCSI persistent reservations ARE being handled properly J

More to come, stay posted!

Update: After testing this for a few days, I noticed that although SCSI reservations were being handled properly (which is great), for some reason the kernel on the storage server would stall. Causing the storage system to crash. I’ve only been able to get it to do this, when two ESXi boxes are concurrently accessing the same datastore. I’ve been trying to re-replicate this in different circumstances (one ESXi initiator, using Windows to test the target, etc… but have been unable). I might test the 4.0 release candidate soon.

How To and Guide to getting Lio-Target up and running on CentOS

 ESXi, iSCSI, Linux, Storage, vSphere  47 Responses »
Oct 052010
 

PLEASE VISIT http://www.stephenwagner.com/?p=300 FOR AN UPDATED TUTORIAL.

 

Disclaimer: Please note that whenever doing any of the steps mentioned in this post, if you do not know what you are doing, you can render your linux install usless. Please do NOT use this in a production environment, and only use for testing. I’m not liable if you toast your linux install.

First and foremost, you need to know that from what I understand, the typical kernels that ship with CentOS have numerous patches, modifications, and updates from the typical Linux kernel releases. This is one reason why the releases of the kernels are always behind compared to ones that are actively being developed. I could be wrong, but I think the Redhat kernel patches are applied to CentOS kernels.

This tutorial will walk you through on how to get you up and running in the dirtiest and quickest method. You may and probably will have to modify things, re-compile, etc… to resolve any issues you may run in to.

I wrote this article only to help more people get up and running with one of the only open-source Linux iSCSI targets that has been certified by VMware (Certified when running on certain appliances) to be used in a vSphere environment (supports Vmotion, SCSI reservations, etc…)

I’m going to assume you have CentOS 5.5 installed and is fully up to date.

Anyways, here’s a breakdown of what we will be doing to get Lio-Target to run on CentOS:

  • Download lio-target modified kernel
  • Download lio-utils
  • Compile a modified kernel using existing kernel .config file
  • Compile and install lio-utils
  • Sample commands to setup a dedicated drive on your system as a iSCSI target (to test)
  • Compose two quick and dirty config files so lio-target can run

Download the lio-target modified kernel

For this step, you will need to have git installed. From what I understand git is not an option during the CentOS install, and cannot be installed using the default typical yum repos. To get git installed, we will first add the “RPMFusion” and “EPEL” yum repos.

(Info on how to install these can be found at http://rpmfusion.org/ and https://fedoraproject.org/wiki/EPEL)

Once you have installed these, it’s time to install git. This can be easily done by typing:

yum install git

After git is installed, it’s now time to download the lio-target kernel.

Type in:

git clone git://git.kernel.org/pub/scm/linux/kernel/git/nab/lio-core-2.6.git lio-core-2.6.git

It is now downloading the source. After this is complete, change directory to the new directory that was created, and type in:

git checkout origin/lio-3.4

You now have the source.

Download lio-utils

This is a pretty simple step. If you just completed the step above, make sure you cd back in to a directory that you can use as a workspace, and make sure you do NOT do this, inside of the directory that was downloaded above. Type in:

git clone git://git.kernel.org/pub/scm/linux/storage/lio/lio-utils.git lio-utils.git

This should create a directory called “lio-utils.git”. This step is done.

At this point

You should have two directories inside of your workspace:

lio-core-2.6.git

lio-utils.git

Compile a modified kernel using existing kernel .config file

It is now time to build a kernel. First of all, issue a uname –a and note the kernel you are running. In my case it’s “2.6.18-194.17.1.el5”. I’m going to take a config file from the boot directory that matches the number, and copy it to the lio-core-2.6.git directory, only change the name to “.config”. This is what I would type in on my end:

cp /boot/config-2.6.18-194.17.1.el5 /root/lio-core-2.6.git/.config

This command above would copy the config for the CentOS kernel, and move it to the lio-core-2.6.git directory with the new name of “.config”. Now change into the lio-core-2.6.git directory:

cd lio-core-2.6.git

At this point we are going to run a command to help the config adjust to the newer kernel version. Type in:

make oldconfig

This will spawn numerous messages. You can just go ahead and keep hitting enter. It will seem like an endless loop, however eventually it will complete. Now the next step, this is important. By default, new kernels use a different sysfs structure. We need to turn on the depreciated item that CentOS uses. Type in:

make menuconfig

Navigate to:

“General Setup”, then check (put a star in the box) for “enable deprecated sysfs features to support old userspace tools”.

Now hit tab to select exit. Once again tab to exit at the main menu. We are now ready to compile! To do a quick compile, type in:

make && make modules && make modules_install && make install

Feel free to disapeer for a while. This will take some time depending on the performance of your system. Once done, you now have a kernel with lio-target built in that is compiled and installed.

Keep in mind that this is NOT the default kernel, and you will have to select this to boot when starting your system. To change this, modify /etc/grub.conf and change the default value to whichever item it is (remember that the first item is 0, and not 1).

Let’s boot the new kernel. Safely shut down your linux box, reboot, and when grub shows up, boot using the new kernel you compiled.

Please note: This guide is a quick and dirty way to get this up and running. Since we skipped customizing the kernel, the kernel you compiled will no doubt come up with errors on boot. I simply ignore this. You can too, just to get this up and running. You can come back at a later time and refine your custom kernel to be used.

Compile and install lio-utils

This is simple. Change directory to the directory where you downloaded lio-utils.

cd /root/lio-utils.git

And to compile and install:

make

make install

And BAM, you’re done, that was easy!

Sample commands to setup a dedicated drive on your system as a iSCSI target (to test)

It’s show time. I’m still fairly new to the configuration and usage of lio-target, so I’m just posting the commands to get it working on a dedicated disk. There are no manual (man page) entries installed by lio-utils, so you will need to use lio_node –help and tcm_node –help for more information on proper usage.

Keep in mind, DO NOT use your linux disk as a iSCSI target! Let’s pertend we have a second disk in the system /dev/sdb that we want to turn in to a target. This is what we would type:

tcm_node –block iblock_0/array /dev/sdb

/etc/init.d/target start

lio_node –addlun iqn.2010.com.stephenwagner.iscsi:array 1 0 iscsi00 iblock_0/array

lio_node –listendpoints

lio_node –addnp iqn.2010.com.stephenwagner.iscsi:array 1 192.168.0.10:3260

lio_node –listendpoints

lio_node –disableauth iqn.2010.com.stephenwagner.iscsi:array 1

lio_node –addlunacl iqn.2010.com.stephenwagner.iscsi:array 1 iqn.CLIENTINITIATORHERE.com 0 0

lio_node –enabletpg iqn.2010.com.stephenwagner.iscsi:array 1

The above will create a target, and discovery portal for /dev/sdb on 192.168.0.10. This will also disable CHAP authentication, and will allow the initator I specified above to connect.

Please change /dev/sdb to the drive you want to use

Please change iqn.2010.com.stephenwagner.iscsi:array to the iSCSI target you want to call yours.

Please change 192.168.0.10 to the IP of the iSCSI target your configuring. Leave port as 3260.

Please change iqn.CLIENTINITIATORHERE.com to the iqn for your initiator (client). This will be set on the client you are using to connect to the iSCSI target.

BAM, your target is up and running! Keep in mind, this configuration is lost upon reboot.

Compose two quick and dirty config files so lio-target can run

Here’s what you need to put in the config files to make the above config work on boot:

/etc/target/tcm_start.sh should contain:

tcm_node –block iblock_0/array /dev/sdb

/etc/target/lio_start.sh should contain:

lio_node –addlun iqn.2010.com.stephenwagner.iscsi:array 1 0 iscsi00 iblock_0/array

lio_node –addnp iqn.2010.com.stephenwagner.iscsi:array 1 192.168.0.10:3260

lio_node –disableauth iqn.2010.com.stephenwagner.iscsi:array 1

lio_node –addlunacl iqn.2010.com.stephenwagner.iscsi:array 1 iqn.1991-05.com.CLIENTINITATOR.com 0 0

lio_node –enabletpg iqn.2010.com.stephenwagner.iscsi:array 1

After you make these config files. You should be able to start lio-target in a running state, by issuing:

/etc/init.d/target start

And remember, that you can always view a live feed of what’s going on by issuing:

tail –f /var/log/messages

Hope this helps!

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