Blog Archives

What no one ever tells you about cluster hardware redundancy

I was recently reminded about this, so I thought I’d post about it and share the knowledge.  I use mostly HP hardware, so in this setup, lets say we have two HP DL585 servers for use in a Windows cluster.  I also have dual fibre channel interfaces in each server.  Externally lets say we have two separate fibre channel switches.  For storage, its an MSA1500 external fibre channel SAN with over 1TB of RAID storage, partitioned for use in a cluster.  The MSA1500 has dual controllers and each controller has its own fibre chennel interface. 

To connect it all together, each server connects one of its two fibre channel interfaces to one physical SAN Switch.  The MSA1500 SAN controllers each get connected to a separate physical SAN switch.  The goal here is to optomize hardware redundancy and make this configuration as fault tolerant as possible.  But here is where the issue comes in. 

No one tells you that you need special software running on each node of the cluster to handle the hardware redundancy.  If you don’t have this software in place, what you will find is that Windows will see two SAN storage arrays.  One of them will be inaccessible since you can only have one physical connection active.  I had to call HP support and go through several explanations of what I was trying to accomplish with all the hardware redundance before I was told about the software I needed.  Its called MultiIO or “Multi Path IO”.  If you do a search on the HP support website, you will find HP MPIO Basic (there are two versions, basic is fine for most people).  Download this software and install on each node and amazingly you will find that things work much better.  From the documentation I saw, there is no indication of needing this software, but in this kind of highly resiliant configuration it is necessary to use MPIO to control the hardware redundancy. 

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RSS feed post limits

This is something that both annoys me and and yet I can understand its reason for existing.  Have you ever subscribed to an RSS feed and its limited to only a few posts/items (lets say 15 is a standard)?  I can certainly understand the need to limit RSS feeds content, there are plenty of reasons why a reasonable number for the history limit is a good idea.  However, 15 is a bit low, especially on sites that offer news or updates.  I recently subscribed to a feed that had posts of a humorous nature, and it limtied me to the last 15 entries.  If I want to see more of the history, I have to go to their website.  15 is also a low number, for a site that may post a few times as week, it won’t take long and I’ll start to miss posts if I don’t frequently check that feed.  On my blog, I allow the last 100 posts to be downloaded, and don’t mis-read me here, that is way too high, especially for a personal blog.  I’d suggest something like 25 or higher for personal feeds, 50 or higher for a site that posts a few times as week in any category, and more if the site posts many times a week, or even per day.

Newsgator makes client products free

I just read this and was really happy becuase I like the newsgator product line and have to say its one of the best top notch RSS readers out there.  I am definately downloading and re-evaluating these apps in their free form.  If you don’t know what RSS is or maybe you do and don’t really like your RSS reader, check out the link about and give NewsDemon a try. 

The Mosquito – kids can hear it, most adults can't

Ok, I’m a little late, almost 2 years late, but I just heard about this and think its really cool.  I read this article and this one is also good, and got curious, so from there, I came across this link which will let you download a tone generator with which you can generate your own custom tones and test your hearing abilities.  I tested myself and can hear up to 18Khz (18000.00Hz), but nothing over that.  So I should be able to hear the teenager mosquito ringtone just fine, which is around 17Khz.  I could hear all the sample sounds out there on the internet, and with the tone generator I mentioned, I found the limits of my hearing abilities.  Just a warning here that listening to these tones is annoying, its not a pleasant sound, and leaves a bit of a ringing in your ears.  I would advise moderation here when playing around with it.

Home media management

I came across this software over the weekend: Media Center 12

Its a really nice media management package that has all the features I was looking for.  It can catalog my media including pictures, audio and video.  It can create various types of playlists, and even has a theatre mode for easy use on the PC or a TV.  You can even run a media web server and use it as a remote control for the media center and play audio/video or slideshows by clicking links on the web interface, what you select starts playing on the display connected to the server.  I really like this package, its got some good plugins and skins and is the best one I’ve tried yet. 

Sunbelt Exchange Archiver

I am working on evaluating trying to evaluate the new Sunbelt Exchange Archiver from Sunbelt Software.  It was just officially released yesterday (11–19–07) and made available for download from their website.  I went ahead and downloaded it yesterday, and spent most of my day today trying to get it installed and working so I can take a look at it first hand.  Right off the bat I had problems getting it installed.  The servers I’m using are test servers on an isolated network, so they are not routinely patched and maybe that is playing a role in my issues.  What I do know is that mcvcr71.dll was not properly registered and caused the installer to fail.  After giving up on fixing that for now, I went to another test server and trie the install.  On the second machine I got past the mcvcr71.dll issue and this time had an error when attempting to create a mailbox for the superuser account. 

I’m waiting for a call back from Sunbelt support to help me get the product installed.  I’m impressed by the software’s functionality and apparent ease of use.  I have a few questions about deploying it in a global diverse network, and need to get more information from them for testing and putting together a deployment plan.  I watched their hour long product walk through via LiveMeeting, and really liked what I saw.  I’ll post more about my experiences with this product as I go along.

Sunbelt Exchange Archiver

I am evaluating Sunbelt’s Exchange Archiver and have to say that I’m initially very impressed.  I just watched a webcast where they did a product walk-through and discussed all the various features of the product.  It appears to be very robust with several useful options many other archiving solutions do not have.  For my company, I think this could be a great addition to our infrastructure to help reduce storage of messages on the Exchange server and help reduce backup times.  It also makes archiving a back-end process eliminating quotas and manual archive methods and taking the responsability off the end user.  I am working on getting a demo of the software to try out in real life and may evaluate it on my own person Exchange system.  According to the website the archiver will be available for download on November 19th.

Using local GPO templates in Windows Vista

One of the things I found tricky about switching to Windows Vista was setting up local GPO Settings.  I opened gpedit.msc and was intentionally trying to add a .adm file for Office Communicator 2007.  I tried everything I knew how to get the .adm file to show up in gpedit, but I couldn’t figure it out.  I tried copying the communicator.adm file to C:windowsinf and C:WindowsPolicy Files and nothing worked.  I even ran across an article on converting .adm files to .admx format for Windows Vista using the ADMX Migrator.  When I tried to convert the file, I got 126 errors and decided that this may not be the way to go.  Finally I found an article on how to add the legacy file format and get the job done.  Its actually already capable of loading the legacy .adm file locally, and here is how to do it…

1. Open gpedit.msc
2. Expand either computer configuration or user configuration
3. Right-click on the Administrative Templates folder and select “Add/remove templates”.
4. Browse for the .adm file you wish to load and select it for opening.

You now have the .adm file loaded and you can then make changes and configure the policy settings.  Also I’d suggest turning off the User Access control option (under control panel > User Accounts) so that you don’t have 500 prompts from Vista asking if you are sure you want to do stuff.  How annoying!  🙂

Microsoft Windows Steady State

Microsoft has recently released Windows Steady State. Its a free application that lets you lock down a windows computer and make it usable in a public environment. It reminds me of my fortress or zenworks days, but its much easier to work with. You can download Steady State from Microsoft and give it a try. This would be great for mall kiosk computers or other types of publically accessible computers. It can even reset all your settings and configuration after a reboot in the event someone does hack the system.

review – at&t TILT

I have had the TILT with at&t for about a week now. I have to say this is the best phone I have used to date. Here are some highlights of why I like this device..

1. Its sleek and visually cool looking, coloring is modern and glossy.

2. The weight of the phone is indicative of being well built, it feels sturdy and tough.

3. It has plenty of onboard memory; you can customize the device, install apps and have plenty of onboard memory left without the need of a storage card.

4. Onboard GPS radio is neat; this is my first phone with true onboard GPS. A perk is that both Google maps and windows live search work with the onboard GPS radio for free.

5. The speed of this device to a data network is amazing. Over HSDPA I can download at nearly 1mbps which is not bad, although this connection is theoretically capable of much faster sped, but it’s still way better than EDGE!

6. You can use this device as a wireless modem, so when you travel or go somewhere that doesn’t offer free internet access, you can connect over Bluetooth to a laptop and get on the internet for free using your phone’s data plan.

7. Windows mobile 6 pro seems much more stable and visually attractive.

8. Battery life is not bad, in one day I am only using less than 50% of the battery with normal to light usage.

9. You can be on the phone and receive e-mail and use the data connection at the same time. No longer does using the phone disable all other radios on the device. You can now get important e-mail while talking on the phone.

10. Mobility! I can browse the web, make a blog post, track my position with GPS, take pictures, connect to wifi, use bluetooth devices, conect to VPN, run Citrix applications and sooooo much more, all while on the go.

There is more I will post about this device later, but those are the main points…