Gregory Strike

How to Expand/Extend an iSCSI Volume without Rebooting

Apr 172012

I was trying to extend an iSCSI volume on one of my SQL servers, but I didn’t want to take any downtime on the databases. The iSCSI volumes I wanted to extend held the databases. This is a quick post, as there’s not much to it and I wanted to make sure I got this out there.

The first step is to increase the volume size from the iSCSI provider. In my case, I am using a LeftHand P4000 SAN and have increased the Volume size from 30 GB to 100 GB.

When going back into Windows (I’m using Windows Server 2008 R2), trying to extend the partition wont work because Windows doesn’t yet know that the size of the disk has changed. So we need to let windows pickup on the change.

To let Windows pickup on the changes on the iSCSI resize, open Disk Management and then restart the “Virtual Disk” service from Services. The “Virtual Disk” service may not be running unless Disk Management is open. This will not disconnect the volumes, all data will still be availble as this service only handles the management piece of the drives.

After I originally posted this, it turns out that this still may not update the disk information. So if the service restart doesn’t pick up on the change launch DISKPART.

C:\Users\Administrator>diskpart

Microsoft DiskPart version 6.1.7600
Copyright (C) 1999-2008 Microsoft Corporation.
On computer: VMTST01

DISKPART> list volume

  Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
  ----------  ---  -----------  -----  ----------  -------  ---------  --------
  Volume 0     D                       CD-ROM          0 B  No Media
  Volume 1         System Rese  NTFS   Partition    100 MB  Healthy    System
  Volume 2     C                NTFS   Partition     49 GB  Healthy    Boot
  Volume 3     E   iSCSI Volum  NTFS   Partition     30 GB  Healthy

DISKPART> select volume 3

Volume 3 is the selected volume.

DISKPART> extend

DiskPart successfully extended the volume.

DISKPART>

Here I extended the volume, even though it “extended” to the same size. I then restarted the “Virutal Disk” service again and it appeared to pickup the changes.

After the service had restarted, I was able to successfully Extend the volume from the Disk Management utility, right-clicking on the Partition, and choosing Extend Volume.

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XenServer Host Failed – What Now?

Computing No Responses »

Apr 162012

Not too long ago, I had one of my XenServer hosts crash due to a hardware failure. It was not my Pool Master. When a XenServer host crashes the virtual machines running on the failed server can’t be controlled, so we’re unable to tell them to start up on another host. The XenServer pool still considers them running, however, they’re not listed in XenCenter. Hopefully this can help some of you get back up and running a little quicker.

The first couple steps were taken from Citrix’s document, XenServer System Recovery Guide. It’s short and straight forward so if you need more information on these steps, please refer to it.

These commands need to be run from a functioning member of the pool. The first thing to do is find the UUID of the failed server.

[root@XS01 ~]# xe host-list params=uuid,name-label,host-metrics-live

uuid ( RO)                 : 542926d8-a1c6-43a9-8ee3-92072214e9bb
           name-label ( RW): XS01
    host-metrics-live ( RO): true

uuid ( RO)                 : df28090c-cde8-495e-a70e-3e0b2879fdcb
           name-label ( RW): XS02
    host-metrics-live ( RO): false

uuid ( RO)                 : f2f13fcf-8ff4-4bbb-b281-af4cc5db91cb
           name-label ( RW): XS03
    host-metrics-live ( RO): true

From the above output we can see that the XS02 host is the server that died and it has a UUID of df28090c-cde8-495e-a70e-3e0b2879fdcb. But now the question is “Which VMs were running on this server?”

[root@XS01 ~]# xe vm-list is-control-domain=false resident-on=df28090c-cde8-495e-a70e-3e0b2879fdcb

uuid ( RO)           : f763254e-b77f-30a4-0a5c-8a43d880d5dc
     name-label ( RW): VMSERVER01
    power-state ( RO): running

uuid ( RO)           : 7ccbe7b2-089a-412e-8e88-af2175bb0c4a
     name-label ( RW): VMSERVER02
    power-state ( RO): running

The resident-on parameter in the above command is the UUID of the failed server. We can see that I had two VMs running on that server. Even though the pool says they are running, we should check. Depending on the reason we lost the host, the VMs may actually still be running. So to be sure I was attempted to ping both VMs and they were not up. If they are up, you may be able to RDP to them and shut them down cleanly.

Let’s now tell the pool that the VMs are powered off.

[root@XS01 ~]# xe vm-reset-powerstate resident-on=df28090c-cde8-495e-a70e-3e0b2879fdcb --force --multiple

Caution!  Incorrectly using the  --multiple option could result in ALL virtual
machines within the pool being reset. Be careful to use the  resident-on
parameter as well.  Alternately, you can reset VMs individually.

This will reset the power state and we can now see the virtual machines in XenCenter.

It would now be a good time to try and ping all the VMs affected. Depending on the type of crash of the host, the VMs may actually still be running. If you can still ping the VMs, try to get a clean shut down of them (We don’t want to start up two of the same VM.) Once verified the VMs are actually shut down, start the VMs back up using XenCenter on another host.

Again, in my situation, we had a hardware failure and I will not be booting this host back up into the pool. To remove the server from the pool I did the following.

[root@XS01 ~]# xe host-forget uuid=df28090c-cde8-495e-a70e-3e0b2879fdcb

Again, the UUID here is the UUID of the failed server. Now the host should no longer appear in XenCenter and it’s nice and clean… Wait a minute! What’s this?! Now the local Storage Repositories that were on the failed server appear! Ok, we need to tell the pool to forget those as well.

First we have to find the UUID of the SR’s that were on the server.

[root@XS01 ~]# xe sr-list params=uuid,name-label,host

Look through the list, you should see some SRs where the host says “Host Unknown” or “Host not found” something similar. These are likely to be the SRs that were on the failed host. Verify you have the correct SRs and then tell the pool to forget them.

[root@XS01 ~]# xe sr-forget uuid=[UUID_of_Storage_Repository]

Do the above command for each SR UUID that is abandoned. Once done, XenCenter should be all cleaned up and we can now focus on rebuilding a replacement server.

Homemade McDonald’s Big Mac Copycat Recipe

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Mar 122012

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For a couple months now I’ve been wanting to tackle recreating the famous McDonald’s Big Mac at home… or as my wife would say, “I’ve had a bee in my bonnet.” The goal here was to come as close as possible to the real thing and then of course enjoy the delicious sandwich with the one I love. The outcome? NAILED IT!

In fact, the outcome was so close to the real thing that I decided I had to go against my standard blog posts of nerdy computer geekdom to make sure I shared my success with all of you. Hopefully, this can inspire others to attempt the same.

A rare photo of the actual recreated Big Mac sandwiches.

Before trying to recreate the sandwich I needed to do some research on it to see what others have done. In my research I learned a little bit of the history on this amazing burger. Did you know that it was created to directly compete with the “Big Boy” burger? Mmmm… Love Big Boy. It’s too bad there aren’t any in my area anymore.

Anyway, before any of you think that I did this on my own, I want to make it clear that I’ve really only modified other Big Mac copycat recipes that are already available online. My versions are based on these two links (Copycat McDonald’s Big Mac Sauce for the sauce and McDonald’s Big Mac for the assembly) with only slight modifications.

McDonald’s Big Mac Sauce
1 Cup – Miracle Whip
1/3 Cup – Sweet Relish
1/4 Cup – French Dressing
1 Tablespoon – Sugar
1/4 Teaspoon – Black Pepper
1 Teaspoon – Minced Onion

I’ve left this recipe untouched from the original post for posting, however, when I made the sauce I ended up adding a little more relish then what it calls for.

Mix all the ingredients together in a bowl, cover and refrigerate for at least an hour. This will help all of those yummy flavors get to know one another.

The above recipe makes about two cups of sauce. So, I had PLENTY left over sauce when I made only two Big Macs.

McDonald’s Big Mac & Assembly
1 Hamburger Bun with Sesame Seeds
1/2 Additional Hamburger Bun
1/4 lb Ground Beef
1 Dash Salt
~~1 Tablespoon Kraft Thousand Island Dressing~~ — We’ll use our special sauce above.
1 Teaspoon Finely Diced Onion
1/2 Cup Chopped Lettuce
1 Slice American Cheese
2-3 Dill Pickle Slices

This recipe can be found at Food.com. They have a cool tool on there to automatically calculate ingredient quantity. I found that 1 lb of ground beef will make 3 Big Macs (6 patties total).

1. To prepare the middle bun, using a serrated knife slice the top crust off of a the top of a bun. (or the bottom crust off the bottom of a bun).

2. Using an electric griddle, set it to around 300-350 degrees. Lay the buns on the griddle to give them a slight toasting. Don’t forget to toast both sides of the middle bun. Once toasted, pull the buns off of the heat and set aside.

3. With the ground beef make two thin patties per Big Mac with a circumference slightly larger then then buns. Lightly salt.

4. Cook the patties on the griddle for about 3 minutes on each side. If you wanted you could also melt the slice of cheese just before the final side is finished.

5. Assemble the sandwich from the bottom to the top in the following order:

Bottom bun
Lightly cover the bottom bun in some of our Big Mac sauce from the first recipe
Diced Onion
Chopped Lettuce
American Cheese
Beef Patty
Middle Bun
Lightly cover middle bun with Big Mac sauce
Diced Onion
Lettuce
3-4 Pickle Slices
Beef Patty
Top Bun

Whether or not you wish to believe it, I have found that the order is actually pretty important. The order not only allows certain flavors to exist in the correct area, but it helps keep the burger from falling apart as well as keeping the ingredients as fresh as possible before enjoyment.

One slice or two? The original Big Mac really only has one slice of cheese, you may notice in my picture that I have two… GASP! Since I’m from Wisconsin, it’s all good. LOL!

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