RAID, RAID, RAID, you just can't get enough.

When I first heard about RAID technology in my IT 305 class I didn’t know what to think at all. It was somewhat of a in one ear out the other kind of thing to me since it was extremely boring. After a couple weeks I actually began reading and started to understand it somewhat. RAID stands for Redundant Array of Independent Disks. The purpose of RAID is to improve the functionality and cost of storing your data. There are 6 different kinds of RAID not including Nested which is combinations of different kinds. The different kinds and a little description are,

RAID 0     Striped array with no fault tolerance

RAID 1     Disk mirroring

RAID 3     parallel access arrays with dedicated parity disk

RAID 4     Striped array with independent disks and a dedicated parity disk

RAID 5     Striped array with independent disks and distributed parity

RAID 6     Striped array with independent disks and dual distributed parity

Nested       Combinations of RAID levels. Example: RAID 1 + RAID 0

There are different positives and negatives to using each kind of RAID. There are also minimum requirements, kind of like when installing certain software on a computer, sometimes you may not have enough RAM and the program will not install. Same thing with RAID, if you do not have the minimum requirements then you will not be able to implement that particular kind.

RAID 0 is the cheapest form to use and it requires a minimum of 2 disks. It has a storage efficiency of 100%( which is pretty high in my opinion) and it has a very good Read and Write performance with no penalty.

RAID 1 has a high cost & it requires a minimum of 2 disks. It has a storage efficiency of 50%.( not looking so good) The Read and Write performance is good and the write penalty is moderate.

RAID 3 has a moderate cost and requires a minimum of 3 disks. The storage efficiency of it depends on how many disks are used, the higher the number the lower the efficiency. It is good for random reads and very good for sequential reads. It is poor to fair for small random writes and good for large sequential writes, the write penalty is high.

RAID 4 has a moderate cost as well and again it has a minimum of 3 disks required. The storage efficiency is dependent on the number of disks, the higher the number of disks the less efficient the storage. It is very good for random reads and good to very good for sequential writes. It is poor to fair for random writes and fair to good for sequential writes. RAID 4 also has a high write penalty.

RAID 5 has a moderate cost and needs a minimum of 3 disks. The storage efficiency depends on the number of disks, more disks are less efficient. The read performance is very good for random reads and good for sequential reads. The write performance is fair for random writes, it is slower due to parity overhead and it is fair to good for sequential writes. RAID 5 has a high write penalty.

RAID 6 has a moderate cost but it is more than RAID 5. Its storage efficiency is the lowest out of all of them and it has the highest write penalty.(ok now for some good news) The positives of RAID 6 are that it is very good for random reads and good for sequential reads as well. It is good for small random writes as well (remember it has a very high write penalty so you don’t want to be doing a lot of that.)

To wrap things up different RAID is better for different tasks and depending on what you plan on doing with or to your data you should plan accordingly if you choose to implement RAID or else you might as well not have done it.

Firefox is the BEST!!!

Have you ever heard of Firefox? Of course you have, who hasn't? It's the most popular internet browser, it's fast, it's efficient, you can do your Blackboard homework, quizzes, and exams on it and to top it all off, it's free. If you made Firefox would you try to capitalize on it? Maybe charge $4.99 per download? Possibly. Part of the reason Firefox is so good at what it does is because it is open source. Mozilla is open to suggestions and full fledged help from everyday people that have knowledge on the subject. Since Firefox is open source if you are a programmer or know how to tweak programs or write them then you could download a special version of Firefox and alter it to your liking for your own personal use. Firefox is one of the leading internet browsers out right now. It is an extremely stable browser even though it has not been around as long as it’s closest contender Internet Explorer. For some odd reason Internet Explorer can’t manage to get rid of all of it’s bugs and crashes and will inexplicably quit among other things. Firefox does not have that problem, at least not as often anyways. Firefox is actually recommended by professors at my college. They tell students to use Firefox when taking exams because it is guaranteed that all of Blackboards buttons and configurations will be recognized. Firefox makes everything easier for me, if I want to share pictures with my friends then I can simply right-click and select “copy image location” and the direct URL to the image will be copied to my clipboard for sharing. In other browsers that is not always an option. The absolute best part of Firefox has to be without a doubt, the plug-ins! At one time I actually had a plug-in that cloaked my IP address, I had one that allowed me to use Twitter as I surfed the web, and you can even get media players so that you can control your music via Firefox. All in all Firefox is an extremely good browser and because it is open source it is constantly being updated and improved keep an eye on it and if you don’t use it yet I’m sure you will convert sooner rather than later. Here's a link to download it now if you like Firefox Download

Storage performance management

I read the article "Storage performance management: 10 storage system performance tips" by Stephen Foskett. This article is about exactly what the title says, it gives us 10 suggestions of how to improve your storage systems performance. For starters there is no cure all to storage system problems.

• Tip 1 from the article was to “Freshen the firmware and drivers.” This tip is simple enough and most people update their drivers and firmware regularly anyway. There is usually an automated alert saying an update is necessary.
• Tip 2 was to “Question the queries” this tip basically says to adjust the I/O workload prior to a bottleneck occurring. In doing so the bottlenecks can be minimized and everything will run smoother.
• Tip 3 was “Break down backup bottlenecks.” This tip suggested using something called CDP, CDP is Continuous Data Protection, CDP backs up data as it is submitted rather than backing up everything at a designated time when most resources would be directed toward backing up files, this method instead uses very few resources to back up continuously and cuts back on backup bottlenecks.
• Tip 4, “Offload virtual machine I/O with VAAI this tip suggests using VMware vSphere 4.1 the end result of using this could be drastically reducing the I/O workload as well as less traffic over the SAN.
• Tip 5, “Balance virtual machine I/O with SIOC” this tip actually doesn’t accelerate performance according to the article, it just keeps everyone happy with the appearance of better performance.(I will attach a direct link to the article at the end of this entry that tip did not make any sense to me at all)
• Tip 6 was “Streamline the server side” this tip described how to use Network Interface Cards, HBAs, and RSS to accelerate performance by distributing processing across multiple cores.
• Tip 7, “Get active multipathing” this tip says that creating more paths to transfer data will improve the storage performance.
• Tip 8, “Deploy 8 Gbps Fibre Channel.” 8Gbps FC are switches that are faster than the more common 4 Gbps FC. 8 Gbps FC can handle twice as many I/O requests and they are twice as fast.
• Tip 9, “Employ 10 Gbps Ethernet.” 10 Gbps Ethernet is a faster ethernet cable that is relatively new and if the old ones are replaced with 10 GbEs then the transfer speeds would jump basically by 10.
• The 10th and final tip is to “Add cache.” This tip is a pretty good one since the more cache you have the more data can be transferred without halted operations and slowed systems.

Here is the link to the original article if you would like to read further and get the full explanation of these 10 great tips. 10 Tips

The Cloud

Every time you send an email, upload a picture, or upload a file to any website you are using The Cloud. Using The Cloud means having information or a file readily available as long as you have an Internet connection. One of the most common ways of use is when people email themselves files for retrieval at a later date. If you think about it though whenever you send an email a copy is saved in your sent folder so even sending an email to your parents is utilizing The Cloud. Most file sharing websites will give you a few GBs of space for free when you open an account making your files secure and readily accessible at all times as well. Most sites allow you to purchase space for a very reasonable price maybe $15 per month for 200 GBs of space. This is basically the equivalent to having an external hard drive with you at all times. Personally I use the cloud almost daily, I actually just finished a group project for my speech class about 10 minutes ago and emailed it to everyone including myself so that I could edit it later on, it eliminated the need for a USB drive(which I have just FYI). But I will be editing the presentation later on and probably emailing it back to myself again to show everyone when we meet up tomorrow. The Cloud is a pretty awesome concept, I never knew the name or term for what I was doing until this class, I had even seen the Windows 7 commercials but never read into it, I just thought it was something that was exclusive to Windows(I have a Mac so that stuff doesn’t really concern me). I was wrong and I’m glad that I know what it is now, I have been utilizing The Cloud since I was 14(7years) and I just now found out what it was.