CAT | Uncategorized
Introduction
You really cannot appreciate the need for a solid backup solution until you need to restore that crucial piece of business critical data. Whether it’s a whole server or just one word document it is always important to know that the files are available to be recovered. There is no single solution that works in all scenarios and it is important to select the technologies that meet the needs of the individual site. This article will look at a number of different technologies and try to demonstrate how they can be used in a business environment and help negate the need to use companies like Kroll Ontrack to perform data recovery on hard drives which can be incredibly costly.
Shadow Copy / Previous Version Client
“Shadow Copies for Shared Folders is a new file-storage technology in the Microsoft Windows Server 2003 operating systems. Shadow Copies for Shared Folders provides point-in-time copies of files that are located on a shared network resource, such as a file server. With Shadow Copies for Shared Folders, users can quickly recover deleted or changed files that are stored on the network without administrator assistance, which can increase productivity and reduce administrative costs.” (Shadow Copies for Shared Folders Technical Reference)
This technology is the basis of the Previous Version client and allows recovery of accidently deleted files without having to request tapes or an online restore which may incur further delays in restoring the data. The snapshots are stored on your file server and you should make sure that you have sufficient space to store all your data as well as shadow copies. So that you don’t run out of space on the server a maximum size for the shadow copies is defined and at each snapshot the server will calculate if it can store the next snapshot in the data store without deleting older versions. When it can no longer store new snapshots Shadow Copy will delete the oldest snapshots to make way for the newest changes.
As mentioned this is a nice technology to quickly recover a few files or folders but should NOT be considered a backup solution on its own as you are reliant on your server always being online and having sufficient space to store enough copies of the data that you can restore what you need to. Shadow copy does not allow for hardware failure and should your disk array fail in the server you will lose the data as well as the previous version snapshots.
Tape Backup
Tape backups have been around almost as long as computers have and writing data to a magnetic tape is a tried and tested way of keeping a copy of the data that can be taken off-site to cover the loss of a server. Today backup tapes are able to store up to 1.6TB of data (depending on tape model and compression) on a single cartridge. As a result the tape backup is still widely used today as the backup solution of choice in the workplace as after the initial expenditure of buying the tape drive and software to backup your infrastructure there is little ongoing expense involved in maintaining the tape based backup solution.
The key thing to remember when using a tape based backups is to NOT keep your backup tapes in the same building as the server that you are backing up. You can backup all your data and keep a full year of backups but if they are sitting next to your server and there is a fire you lose both the server and the tapes and are unable to restore the data. It is recommended that once data has been written to tape that the user responsible for changing the tapes removes the tape to a secure location. There are companies, such as Iron Mountain, who offer services to collect tapes on a regular basis and store them in a secure vault. This can give you the peace of mind that you only have the minimum number of tapes on site at any one time.
The number of different backups you keep is completely dependent on how far back you feel you need to recover data. One tape that is overwritten daily is not a safe solution and while it is possible to use a completely new tape for each backup this can quickly become a costly way of backing up data. The most common backup hierarchy is the Grandfather, Father, Son scenario. In this scenario your Son backup would usually be your daily backup and then at the end of each week the Friday/Weekend backup is kept as the Father and at the start of the new week a new set of Son backups is created. At the end of the month the last Father backup is promoted to Grandfather and the process starts again at the beginning of the new month. It is recommended that the Grandfather backups be kept for a set as a reference of the data at that point in time. Over the course of a year using this technology you will need to have 21 tapes to rotate through. (4 tapes for Monday – Thursday, 5 tapes for the Friday/Weekend backups and 12 month end tapes). If you would like to keep two weeks of daily backups you will need a further 4 tapes to cover the second week.
Online Backup
If you have data based across multiple sites or you don’t want to be forced to change tapes on a nightly basis an online backup solution may prove to be a viable solution. In the same way as the tape backup will capture your data on a nightly basis and write it to a magnetic tape the software here will connect to a 3rd party data server and upload the data to be stored here.
Rather than taking a full backup of all the files each night the online backup solutions usually look at taking an initial base backup on site which is integrated into the off-site storage platform and then each night an incremental backup will copy changes since the previous backup to the platform. As a result of this files are stored based on the number of impressions that are pushed to the backup platform i.e a file can be backed up on day 1 but doesn’t change for 2 months at which point the second impression is saved to the backup platform whereas a file that changes daily will write a new impression each time that file is backed up. The number of impressions you want to keep is dependent on the money you are willing to pay for storage.
When planning for an online backup it is important to work out how much data will be changing on a daily basis and needs to be sent across the Internet to the storage platform. If your Internet connection doesn’t have sufficient bandwidth you will not be able to take a full snapshot each night and could end up with gaps in your backups that prevent complete restoration of all the data.
Disaster Recovery Site
If the nature of your business means you cannot afford to be offline whilst your IT infrastructure is restored then a DR site may be something worth considering. If your Infrastructure is severely crippled then you are able to switch core services to another site and your users are able to continue working with minimal disruption.
Microsoft developed the DFS Replication technology in Server 2003 to enable file shares to be replicated between multiple servers in real time. In the case of your primary file server failing you simply need to switch your referral server to your DR site and users will be able to access data through the same file shares and shouldn’t notice the changeover. Replication of databases such as Microsoft Exchange or SQL is not as easy to replicate in the same way as the database files are constantly changing with each access. In these cases 3rd party applications such as DoubleTake or XOSoft (formerly WANSync) can be used to make sure that your databases are replicated in real time to the DR site so they can be switched over as needed. With these scenarios users are able to keep working whilst the core infrastructure is recovered and then any changes made whilst working in the Disaster Recovery scenario can be replicated back to the main offices.
The Disaster Recovery solution is not a cheap solution as you need to pay for a second set of servers to replicate the data to and run in an alternate site such as a data centre however the running costs need to be compared with the cost to the company whilst services are restored.
What should YOU do?
What you do now is a very individual decision based around the needs of your business. There are companies that implement all four different technologies mentioned to provide resilience against there being an issue with any of the other backups however this is a costly solution that is not viable for a number of small companies. For most, implementing either the tape or the online backup along with the Shadow Copy snapshots will provide enough security to restore the data should files be deleted or a server fail.
It should be noted however that the backup to tape or offsite should never be taken for granted and ignored. As part of any backup strategy you should be looking to run test restores from your backup media to ensure that you can recover the data you have backed up.
Backup · disaster recovery · DR · server · tape
Having spent a long time ignoring this blog or simply linking to amusing things on the net that I found through sites like stumbleupon.com I think its time to try and focus what I am writing about and see if I can get a good set of useful articles written.
Having thought about it for about 5 minutes this morning I decided that it should be something related to what I do on a daily basis but also something that I have interest in otherwise what’s the point? Visualization was a first thought but I already read a good blog about vmware (http://www.techhead.co.uk) which I would probably end up plagiarising and isn’t the reason for this. The other thing that I am keen on at the moment in the world of technology is network monitoring and the technologies you can use for it.
Now I will say now I’m quite biased when I am looking at setting up a monitoring solution as I don’t really want to say for the extra hardware or software I use to monitor everything. This does mean I will look for a good open source application(s) to carry out a task and which I can customize rather than paying for a boxed product that does some of what I want to do but not everything.
Now I still like sharing interesting pages I find on the web but I may need to split the blog into 2 sections to look more professional… Still haven’t decided yet but don’t worry the random site links will still be there!
So what’s my first entry under the new incarnation of the blog? I think I will write up the “Howto” on building an open source monitoring machine that can keep an eye on your network. Expect it in a few days.
This is a brilliant post that I stumbled across this morning. My favourite two quotes are:
If debugging is the process of removing software bugs, then programming must be the process of putting them in. – Edsger Dijkstra
and
Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it. – Brian Kernighan
Stumbled across this this morning and its just amusing. Well worth a watch
Hello World!
24
4 Ways to Disable Security warnings in Windows Vista.
1 Comment · Posted by digg in Uncategorized
Disable the User Account Control (UAC) feature on your Windows Vista computer.
Makes Vista a lot less annoying for power users.
Computer · Microsoft · Uncategorized · Vista · Windows
If you don’t have anyone to celebrate it with then its fairly crap!
Oh well. I just have to get on with life!
Back in the day when Coke produced decent adverts the sign that Christmas was coming was heralded by the bright red Coke trucks and some happy music.
This year Coke have given us a CRAP advert that is poo and no where near as good.
Gemini have announced the new product in their iSeries line of DJ equipment – the iTrax which allows you to plug your iPod into the top of the mixer and have your entire music collection at your fingertips. As with most mixers you get an eq on the iPod channels, mic insert, headphone jack, option for aux inputs (CD/turntable), master out and record out. Another useful feature is the video out which will allow you to connect your mixer to a projector/tv and make use of the video features of the latest gen iPods. 
There are however some features that make this a less than desirable product to own
You will need 2 iPods (who has 2) so that you can mix from track to track.
If you two, then you will need to have the same collection on both as there’s nothing worse than having the next track on the source you are currently sending to the speakers.
This has all been done before anyway by Numark with their iDJ which is now in its second incarnation. The first iDJ had the same features as the Gemini product but without the video (IIRC). The second gen iDJ recognises the fact that people don’t have two iPods and will allow you to mix from track to track through just a single music player – a much better solution if you ask me.
The Numark iDJ (2 iPod) is available from decks.co.uk for £169 and the iDJ2 for £429. The Gemini iTrax is reported to be coming in at around £100 which is what should be expected for something like this.
If you are seriously considering buying an iPod DJ package and have the money to spend go for the iDJ2 any day as the other two require you to have two iPods to use it properly!
Source [Gizmodo]
audio · DJ · iPod · Uncategorized
It is with sadness that I learnt about the death of possibly the greatest animal lover in recent history. Steve Irwin was an amazing person who did so much for animal awareness and he used his celebrity status to further this.
Steve died whilst filming a documentary off the Batt Reef in Australia, receiving a barb from a stingray to the heart. Paramedics were rushed to the scene but they couldn’t save him. Steve is only the second person to die from a stingray in Australia.
More details can be found at the BBC website
animal · australia · death · Steve Irwin · Uncategorized
Well having heard all the hype about the film I was intrigued to see what it was all about so Kate and I decided to head down to Reading Vue to catch the film with possibly the biggest hype in recent history and see what it was all about.
It really didn’t live up to what I was expecting. The characters were fairly pointless, the CGI wasn’t brilliant and the fact that it had been “written” from contributions of various people showed as the story never really flowed correctly and the action seemed incredibly implausible. If you haven’t seen the film then stop now as this will “spoil” it for you.
The opening five minutes set the precident for the rest of the film as Nathan Phillips character witnesses the murder of some guy and is chased down by a local Triad boss who will do all he can to prevent him from testifying against him. In steps Samuel L to save Phillips from certain death at the hands of the henchmen before taking him back to the US to testify. The triads get pissed off and put a collection of exotic snakes onto the plane and spray all the flower necklasses with pheromones to make the snakes go “crazy”.
Half-way into the flight, the snakes are set loose and they start to bite people and cause panic. Captain dies as does the co-pilot and Jackson’s character is left to keep order. As with all these films the crappy characters are killed off and the stars survive to save the day.
There was a surprise performance from Kenan Thompson (of Kenan & Kel fame) as a bodyguard to the rapper who has an OCD over cleanliness. The crowning moment of the whole film (apart from the final credits) was the quote from Jackson’s character “Enough is enough! I have had it with these motherfucking snakes on this motherfucking plane!” Apart from this the dialog was fairly sub standard and uninspiring.
Kate did enjoy the snake specialist who was unwilling to come out because he had baby anacondas which had just hatched.
All in all a poor film with masses of hype that will make the director/producers/actors incredibly rich. If Samuel L Jackson hadn’t agreed to put his name to this then there is a good chance that the film would have flopped massively and been a failure throughout whereas it will be loved by many for being bad and a few people (myself included) will feel that our £5.50 was badly spent
On Saturday evening I am flying out to Kenya with my parents and brother to celebrate my mum & dad’s 25th wedding anniversary.
The trip has been booked through Trailfinders and our itinery includes 5 days of safari and 2 weeks of beach holiday in Zanzibar.
If I’m perfectly honest I am looking forward to the 2 weeks on the beach more than the safari if only because the days are starting at 5:00am and that’s gonna be more than a small shock to the system!
Wherever possible I will keep the blog updated with the happenings of the holiday and anyone who is interested can read along.
holiday · kenya · safari · Uncategorized · zanzibar
It’s been over 2 years since I have seen Doogs and now he’s getting married…. Tomorrow will be the first time I have seen him in ages and I can’t wait!
I havent even been back for 2 weeks now and I am really thoroughly bored. I had thought about joining a gym to try to get fit but I still cannot be bothered with that.
I just need something to entertain me!
Well after the success of Tuesday’s presentation I was asked to create another that could be used at the Middle and Senior school prizegiving. This was a much less difficult presentation to organise as there was no music for it to be in sync with and just to be merely a collection of images displayed in order. With just over 100 images and 6 seconds per image I created at 10 minute slideshow that repeated.
However, now that this has been completed I am looking for some work that I can do to keep me going now there is no more to do at Downsend (except their website).
I’m currently in the process of creating a DVD presentation set to Dario G’s Sunchyme and over the past 24 hours have heard the song about 1 000 000 times. It is starting to get quite tedious but in order to get the timings of the various clips accurate I need to listen to it over and over and over again!
Apart from that I have been to a White family lunch. My mum, dad and myself went over to see most of the my dad’s side of the family. We had a really nice meal and it was the first time we had all been together for a long time. My dad showed his complete dislike to animals by scaring off a random cat that had wandered into the garden – everyone was just ignoring the cat but when it walked towards my dad he just shouted at it to “GO AWAY”. As the cat clearly doesn’t understand english a further shout of “BRRRRRRR!!!!” was heard!
Simon “couldn’t make it” but I feel that he would rather spend time with friends over family… tut tut!
Right… off to sleep as I need to get up early tomorrow to sort out the rest of this bloody presentation!
Having spent all of about 2 days revising for ASE I think i now know enough to answer 65-75% of the paper.
I know quite a bit about:
- Software Testing
- Agile Methods
- Software Maintenance
I dont know much about:
- Program Slicing
This could prove to be problematic in the exam!
Degree · Durham · exams · Uncategorized
I should make a special mention to Kate who is now at the grand age of 22.
Remember the Pony is waiting for you and it only had enough food to keep it going until today*
(*No ponies were harmed in the making of this blog)
