May 24, 2007

Backups v. Redundancy

What are difference between Redundancy and Backups? Typically, when discussing redundancy in terms of data storage, you are talking about a RAID. Many people make the mistake of thinking that because you have a RAID you have backups of your data, this is NOT true. But to understand why this is not true, you need to understand the differences between Backups and a RAID and what their purposes are.

What is a RAID?

RAID: Redundant Array of Inexpensive Drive

RAID is exactly what it says. It is an array of drives, all of which are typically identical in specs and based on the configuration you set will divide and/or replicate the data you save to them. A RAID can be set up in several ways, but the most typical are RAID 0, RAID 1 and RAID 5

RAID 0, or striping, refers to a configuration in which you have typically 2 hard drive of the same size and you set them to “stripe” data across both drives. It will generally provide for better performance because the computer can read from both disks when searching for data. This configuration provides no redundancy, and a single disk failure will cause the array to fail and data to be lost.

RAID 1, or Mirroring, is the practice of again taking 2 drives, but instead of striping the data across both drives, the drives mirror each other. With this configuration, you lose half your total storage space (because you are basically saving everything in 2 places), but you will get a performance boost because the computer can then use 2 separate points to pull data from, and if one disk dies, the other can pick up where it left off, which provides basic redundancy.

RAID 5, or a striped set, consists of a minimum of 3 disks, which is configured in a way that the data is distributed across all of the drives, and allows for the failure of 1 drive without data loss. The percentage of lost storage space in a RAID 5 configuration varies based on how many total drives there are (e.g. if you have 3 100GB drives, you have 200GB storage space. If you have 5 100GB drives, you have 400GB of storage space)

There are several other configurations for RAIDs which combine the above setups and allow for better performance or better redundancy. But these are the 3 Basic configurations. For more information about various RAID configurations, including options available via software see the RAID entry on Wikipedia.

What are Backups?

Backups are a copy of data, stored for the purpose of having a second copy of an original source in case of loss of the original source. Typically, backups are run on scheduled intervals. The frequency of a backups and how long you keep a backup for depends on the needs of you and your business. In an environment like a bank, backups are taken every few minutes because the number of transactions processed is very large, and the data being processed is very important. For a small business once a week may be often enough for documents that change, and once a month for archived information.

There are several types of Backup configurations and types including Full, Incremental, and differential. For more information in regards to the different types of backups see the Backup entry on Wikipedia

How to Choose:

When trying to determine which solution is best, you need to ask what your needs are. Do you need to have your computer up and running all the time? Or do you need to be able to replace files they may have been deleted, corrupted, or edited by mistake?

If you need the uptime, then a RAID solution is what you need. RAID solutions (with the exception of RAID 0) provide the most uptime, because if one of the hard disks fails, the others can take its place temporarily. If you need to have older versions of documents, or the ability to recover a lost document because it was deleted by mistake, or someone edited it and saved it incorrectly, then you need a good backup solution. And if you are like most businesses, you need both. In which case, you will need a RAID set up as well as a Backup solution.

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May 18, 2007

Down and Dirty System Tune Up (Part 2)

Extra Steps

So now your computer is clean of Malware, and is protected, but still running slow. Well we are not done yet. The first thing you want to do is open up your event viewer and take a look to see if any errors are occurring, these are going to be your best hints at what is causing a problem, possibly a conflict between two pieces of software, or just a program not running correctly. Also, run your disk cleanup tool and clean out your temp files and cache. Run you disk defragmenter to keep all of your data well organized and readily accessible on your hard drive. These tools can be found in you system tools folder (start -> all programs --> accessories --> system tools) and will help increase the life of your computer as well as keep its performance up to par. And if you are still having problems we have one more place we can look before you should think about seeing a professional. Look in our system information (start --> all programs --> accessories --> system tools --> system information) and look under the hardware resources section for any conflicts in hardware. If you locate any conflicts there is a good chance they are causing your problems. Take the necessary steps to correct the problems. (Things like making sure you have the most up to date drivers for all components help a lot)

Other Helpful Links

  • Sysinternals - www.sysinternals.com - provides a variety of free system tools to help you monitor/fix system problems.

  • Google - www.google.com - if you find something and don’t know what it is, Google it, I’m sure you’ll find an answer there.

  • Symantec - http://securityresponse.symantec.com/ - latest virus news including new viruses and there danger levels.


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May 16, 2007

Note: Always make a backup of your data before doing any major work to your computer.

Why is my computer running slow?

So all of a sudden you windows computer is starting to run slower than normal, you are getting more pop-ups than usual, and programs aren’t working the way they should. Don’t worry; it’s not the end of the world. The following is a down and dirty guide to first cleaning your computer of all the garbage that is slowing it down, and then keeping it clean.

Before we start talking about how to get your system back up and running like the beast it is, we should discuss what could be causing the problem to begin with. Today’s internet is filled with tons of garbage, it’s sad but true.

Two of the most common reasons for sudden computer slowdowns are vicious types of hidden software called adware and spyware. Both are usually installed under false pretences claiming to be these great pieces of software that will speed up your internet connections, give you free games, or pretty screen savers. And while they may do some of the stuff they claim, they also send information about you, your computer, and your internet browsing habits back to its creator (or more likely the person who paid the creator) and they use this information to trigger pop-ups on your computer and in some cases get your email address to send SPAM to.

Aside from these two types of hidden software there is the world of viruses that we must discuss. Viruses come in a wide variety of types and can do many things (almost none of which is good). Viruses are defined as any software that can replicate itself and spread throughout your system or to another system. Viruses have functions that range from sending out SPAM, collecting email addresses from your address book to aid in spamming, turning your computer in to a “zombie” (a computer that is remotely controlled by the attacker to aid in Distributed Denial of Service Attacks), turning your computer into a proxy for a hacker to route his traffic through in order to protect his/her identity, and data loss among many other things.

What can be done?

Now that we know the 3 most common software threats on the internet you may be asking “How do I get rid of this stuff?” well the solution is much simpler than computer shops want you to think. There are a wide variety of tools available for free on the internet to help you with removal of this type of problem. I like to refer to the following as the Holy Trinity of the computer world.

Adaware – made by a company called Lavasoft, Adaware is one of the most popular and most successful programs I have come across on the internet for removing adware and spyware from your computer. The personal edition is available for free download from http://www.lavasoftusa.com/ download the latest version of this software and get the latest definition updates.

Stinger – made by McAfee, stinger is a stand alone virus scanner that scans for about 50 of the most widespread (not necessarily the most recent) viruses out there. It saves a convenient log of what it found so you know exactly what was going wrong. Stinger can be downloaded from http://vil.nai.com/vil/averttools.asp

House Call – a web based virus scanner that is about as up to date as you can ask for. Now with a vulnerability scanner as well as a scanner for Spyware/Adware added this has gone from being a better than average virus scanner to an extremely powerful tool. It can be accessed at http://housecalll.trendmicro.com

Once you have downloaded your tools and have updated them, restart your computer into safemode. This is usually done by tapping the f8 key on your keyboard right after the computer begins to start up. Starting in safemode is strongly encouraged because while in safemode the computer only starts essential services, and loads essential drivers. If a file is in use it sometimes cannot be scanned and even when it is scanned it cannot be removed. So safemode accesses the fewest files needed to get the computer going. Run your scanners in safemode, and delete everything they detect (unless you know that it is a legitimate program, sometimes false positives do occur) chances are you will find a handful of stuff even if you think your computer is clean. After you have run the offline scanners you may want to reboot your computer connect to the internet and run Housecall"s scanner. After this is done the basic scans of your computer have been completed. If you feel the need you can repeat the previous steps as many times as you want until you feel your system is clean (I normally go through two times, just to be sure, with a reboot after the first time around)

How to keep it running well:

So now your computer is Clean, so let’s keep it that way. The most important thing you can do to keep your computer clean, is educate yourself. Be careful of the sights you visit, remember the saying “if it looks too good to be true, it probably is” and don’t download software from untrusted sites. Even if the software seems harmless it can cause a great deal of damage. Secondly, get an antivirus program installed on your computer; many good products can be purchased from a computer store including Symantec’s anti-virus and McAfee to just name two of the bigger ones. Or you can opt to download a free anti-virus like AVG (available at http://www.grisoft.com/)

You may also want to install a firewall on your computer. A firewall is another layer of protection between your computer and the internet. Firewalls come in both software and hardware form, and when configured correctly are very effective in protecting your computer. Sygate is a free software firewall and can be downloaded from http://smb.sygate.com/products/spf_standard.htm but like I said before you must keep this software updated and configured correctly for it to be effective. Do not “allow all connections” or you are just wasting system resources. Take the time to configure the firewall correctly and it will pay off.

Now all the software in the world can’t protect you if you don’t take the basic steps of patching your operating system. Microsoft provides a nice little program called “Microsoft Automatic Update” which comes pre-installed on all windows computers. USE IT. It will keep your computer up to date with the latest OS patches and help in keeping your computer a bit safer on the internet. I cannot stress enough how important it is to keep all of your software up to date with the latest security patches. The companies have only a handful of programmers creating the software and have THOUSANDS trying to break it. Holes will be found, so it is your responsibility to patch them.

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