Backup - from dummie to doctor

Sådan kan cloud fejle: Stol ikke på Microsoft

2012-01-10T18:56:00.002+01:00

Microsoft har for nyelig introduceret deres cloud storage: SkyDrive. Det er, som fx DropBox, et lager på internettet, hvor man kan lægge sine filer, fx til backup.

Der har dog været en sag fremme i pressen hvor en bruger fik slettet alle sine filer:

http://www.comon.dk/art/205276/microsofts-dropbox-konkurrent-blokerer-dine-erotiske-billeder

Årsagen var, at han havde helt lovlige billeder af letpåklædte billeder liggende. Dem havde Microsoft kigget i og besluttet at lukke hans konto. SkyDrive er ikke en hjemmeside, alt indholdet er privat, men alligevel synes Microsoft de vil blande sig i hvad man bruger det til.

Der er altså en måde mere cloud kan fejle på, nemlig at leverandøren får lyst til at slette sine filer.

RAID is not backup

2011-02-23T20:05:00.003+01:00

As I have written in other postings, a RAID setup consists of 2 or more harddrives, which are mirrors or contains the same data. It is done in a way, that if 1 disk fails, no data is lost and the system will continue running.

But why do I say that RAID is not backup, then?

RAID 1-5 can save your data if 1 harddrive fails. If another disk fails before you can replace the bad disk and the data can be mirrord, you have lost all of your data.
RAID only protects against drive failure. Theft, water damage, virus, accidential deletion etc. will still cause you to lose data.
RAID does not protect against RAID failure. If the controller, the hardware which manages the disks, fails you will lose all of your data. And trust me: They do fail. Even the very expensive ones.

Note that RAID 6 will allow you to have 2 drives fail before data loss, but: You are still not fully protected.

All in all: RAID will let your server or computer run without interruption if a harddrive fails, but it will not protect you as a backup should do.

My backup setup 4

2010-09-14T20:55:00.001+02:00

In a previous posting I defined my 3 kinds of data. In this posting I will tell how I back it up:

Okay to loose.
(see a previous posting)
Harder to replace.
(see previous posting)
Ireplaceable.
This data I store on my NAS and I back it up over the Internet to an off site location. The cheapest solution would be a NAS friendship but I don't know anybody who would need a similar solution, so I use a commercial solution.
The service I use is Crash Plan (consumer version). It comes with a backup program (which is free) and that program makes it easy to do backup to any medium. It will only cost money if you (as me) choose to buy their backup over the internet service. Currently I pay $60 for a year and then I can backup a single computer but an unlimited amount of data. Currently that is 460GB !!! They also have a family plan, which removes the 1 computer limit too and a commercial plan.
The Crash Plan program runs on my computer, which I have to leave running when I have new data (a photo shoot easily produces 10-15 GB of data).

My backup setup 3

2010-08-29T20:47:00.000+02:00

In a previous posting I defined my 3 kinds of data. In this posting I will tell how I back it up:

Okay to loose.
(see previous posting)
Harder to replace.
Nothing exists without at least 2 copies at different locations, which is also true for this data. I have one copy at home on 4 small harddrives and a single encrypted harddrive at work with the same data. When I make an update to the one at home (which is not often) I will bring the one at work home and update that one. In this case I am protected against fire etc. and in some degree protected against drive failure. Because I don't check them often, there is still a significant risk that I might loose everything some day.
For that reason, I ought to have it on a NAS at home, but then I'll have to buy another NAS and two harddrives.
Ireplaceable.
(see next posting)

My backup setup 2

2010-08-14T20:42:00.001+02:00

In the previous posting I defined my 3 kinds of data. In this posting I will tell how I back it up:

Okay to loose.
This data I store on my NAS - see previous postings about a NAS. It protects me resonably from drive crash, but theft, fire, flood, human error etc. is not covered. However, it is still a very cheap way to have copies of a lot of data on two drives which is often updated.
Harder to replace.
(see next post)
Ireplaceable.
(see future post)

My backup setup 1

2010-07-31T20:37:00.002+02:00

I have a lot of data - way too much to serious backup. For this reason I have split it into several categories, each of which have different backup strategies:

Okay to loose: Data I get can again, e.g. installation files for downloaded software or music I bought which I can download or rip again.
Harder to replace: I have digitalized a lot of old VHS tapes. If I loose the data I can buy the movies again on DVD. It will cost some money, but it can be done.
Ireplaceable: Pictures, e-mails, documents etc.

See in the next posting how I back these categories up.

Backup is not the most important...

2010-07-14T19:12:00.001+02:00

Backup is not the most important: It is restore.

Imagine that you make your backups regularly in multiple ways with at least one being offsite. One day you need the backup, but it does not work. You might have forgotten a directory, so you do not backup everything you think, you might have forgotten a password for an encrypted file or for some reason the automatic backup have not worked for the last 6 months.

Just as important as taking backup is to test that you can actually restore it. Try it on an old computer or when you get a new one. At least make sure that you can get up and running when necessary.

Howto backup your website or blog

2010-06-28T20:59:00.001+02:00

You can do it by hand, but there are programs that can download an entire website. The one from HTTrack is free and has proven itself for many years. Just give it your web address and it will download everything.

Easy backup of important document

2010-06-14T20:56:00.001+02:00

Are you writing a book or just an important assignment for school? If you want a quick and fast backup, then create a free e-mail account at e.g. gmail.com and mail the file to that. Then you can always get your backup copy if you should loose your laptop or USB stick.

Backup your website or blog

2010-06-07T20:52:00.001+02:00

Today websites and blogs are often made directly in the internet browser and there is no need to store them on your computer.

But what happens when the service you are using disappears? Then your website is gone. Almost. Try to find it on archive.org or search for it on Google and click the "Cache" link. These ways have saved countless websites but they are no guarantee.

How can such a service disappear? History have shown a company have a total system failure thus loosing the data of their paying customers, while the backup was not working. There are also countless examples of companies stopping such service with none or little notice. If you are on holiday when you get the 14 days "eviction notice", you may not get it in time.

Get those pictures off that camera!

2010-05-28T20:50:00.001+02:00

Do you keep your pictures on your camera, and never copies them to the computer? History has countless examples of loosing the first years of their child, the pictures from their honey moon or other important pictures. The camera may get lost, stolen or damaged along with all of the pictures.

If nothing else, make it a habit of copying them to the computer every month or so.

Backup: Help your mom

2010-05-21T20:48:00.001+02:00

When visiting your moms house, she may not have backup and may not be able to make one. Help her out: Just make a copy of her pictures, documents and e-mails onto a USB stick and keep the data under your backup solution. It may not be updated that often, but when her computer fails, it is better than nothing.

NAS friendship

2010-05-14T20:08:00.001+02:00

If you have a friend that has a NAS box of the same brand as yourself, you can often set your boxes to synchronize with each other over the internet. This is a very cheap way of getting an offsite backup.

Just note:

You must trust your friend, as he may see all of your data.
You should not set your boxes to synchronize everything, if you have movie or music collections. It will use all of your band with and may break copyright laws.

What is a NAS?

2010-05-07T20:42:00.002+02:00

NAS is short for Network Attached Storage. Usually it is a box running RAID1 or RAID5, which can be connected to your network and looks like a shared network drive. Then you can access it from any of your computers.

Very often the NAS has a lot of extra features built in, such as photo sharing, bittorrent download, iTunes support and more. If you have multiple NAS boxes of the same brand, your can often set them up to synchronize with each other. This can be used to creates a cheap and automatic offsite backup.

A NAS is a very easy way of running RAID and at the same time get easy access to your data.

How does it fail: CD/DVD/Blue-Ray

2010-04-28T16:37:00.002+02:00

Optical media is still a popular form of backup, and for a good reason: It is cheap and lets you keep the copy "forever". But what is that? In general you should not count on a burnable optical media to last for more than 5 years. The chemistry is changed all the time, and the media are made for practically no money in all sort of far east countries, so you really does not know what you got.

The most common ways to destroy optical media is time, sunlight, heat, moist and scratches. Keep it dark, dry and at a stable temperature, and it will last longer, but don't count on it.

How it fails: Online and cloud backup

2010-04-21T16:30:00.001+02:00

Online backup, often named by the buzz word "cloud", is when you have a program upload your data to a company that will keep it safe. When you needs the data you can download it. This is very easy because the program pretty much takes care of itself, and you get a real offsite backup.

This sounds perfect, and when something does that you can know it is not:

Companies goes bankrupt - online backup companies does too and even though your data exists the servers are turned off.
Data loss - all the usual ways of losing data applies to these companies too. They may have better safety but not 100%.
Got a new credit card? And did you forget to update the number with your online backup? And maby the contact e-mail address was outdated. You might not notice untill it is too late.
You lose the password or encryption key for the backup, you lose it all.

By the way: All of these scenarios has happened within the relatively few online backup has existed.

Online backup or cloud backup

2010-04-14T20:00:00.001+02:00

With todays fast and cheap internet connections it is very popular to make a backup to "the cloud". It usually works like this:

The backup company provides a program which you install.
You tell the program what to backup and lets your computer run until all of the data has been uploaded.
From now on the program will only upload the data that changed, which is usually very little.

One thing to look for, is if the company has a separate restore price. When you have lost your data, it is not fun to find out that you must pay a horrible rate to get your data back. Restore should be part of the subscription.

How does it fail: RAID

2010-04-07T16:37:00.003+02:00

Because harddisks fail often, it is possible to use multiple harddisks together, to get better safety.

RAID is short for Rapid Array of Inexpensive Disks. It will manage multiple disks and let the computer think there is only one disk. There are in general 3 different kinds of RAID in use today:

RAID 0: Scary raid, never use this! This just makes multiple disks look like a big one. Often reading and writing speeds are higher, because multiple disks can be read and written at the same time. But if just one disk fails, you loose all of your data. This makes the disk of loosing data much higher so never use it! Todays disks are so fast, that there is no practical use of RAID0.

RAID1: Usually used with 2 disks but it only has the size of 1. What you get is 2 disks which always have the same data. One can fail, and your system will keep running. This is the most secure form of RAID, but it is not 100%. When one disk has failed, you have no backup until you have replaced it and there are many examples of data being lost in this time span.

RAID5: Used with more than 2 disks, e.g. 5. Only 1 disk is used as backup, so with 5 disks you have the space of 4. As with RAID1 you loose your data if 2 disks fail at the same time and because you have more disks the risk of this happening is greater.

RAID5 works using "parity". Lets take this calculation: 1 + 2 + 3 + 4 + 5 = 14. If you replace any of these numbers with a ?, it is still easy to derive the missing number, e.g. 1 + 2 + 3 + ? + 5 = 14 <=> 14 - 1- 2 - 3 - 5 = ? = 4.

Finally, there is also the risk that the hardware or program which controls the RAID breaks down.

All in all: RAID fails in the same way as harddisks, just not as often. But it does happen, even with very expensive enterprise systems.

How does it fail: Harddisk

2010-03-28T16:36:00.000+02:00

Almost every computer uses a harddisk to store data and it is very popular to have one or more external harddisks. Unfortunately harddisks fail very easily.

A harddisk is made of magnetic disks, just like a video tape, which are read using an arm, just like a record player. It also contains some electronics, that handle error correction and makes it possible to connect a standard interface to the harddisk.

The most common failure is either mechanical, i.e. the reader arm may fall off or just touch the sensitive magnetic surface or that parts of the magnetic surface becomes unreadable. The internal electronic may also fail.

All of these errors makes it impossible to access the data via the standard interface. In reality, most of the data still exists. It just cannot be read easily. There are companies which have specialized in saving data from such situations. They take the disk apart inside a special clean room and uses special machines to read the disks. This is very expensive and out of the range of ordinary people.

How does it fail: Usb stick

2009-10-20T16:36:00.002+02:00

Small, cheap, easy to use and they can take much more of a beating than a harddrive. Their small size is their worst enemy: Forget it in your pocket when washing, sit on it, drop it into the toilet or just plain loose it. Simple stuff no technology can solve.

These small miracles are not everlasting. All flash circuits have a limited number of times you can write to them. The cheap ones the count is 100.000 times, the expensive ones it is 1.000.000 or a bit more. You might not use a flash drive so many times, but if you use it as a working drive, and a program saves changes to it a lot of times, it might eventually kill the drive.

Everything can fail

2009-10-14T22:02:00.001+02:00

The most basic principle in making a good backup strategy is: Everything can fail.

Harddrives break down, DVDs are suddenly unreadable and the fancy "in the cloud" online backup company goes out of buisness.

Think this way: At any time there is a probabillity that a given data storage will fail you. When that happens it will take some time before you realise it, it will take some time to get a replacement storage and it will take some time to make a new backup.

Making your own backup strategy

2009-10-03T19:03:00.002+02:00

Having read the previous posts, you know that one backup might not be enough. There are many ways to make backup and if you want to be well protected without paying too much, you must make a backup strategy for your situation.

In order to make a backup strategy you must know about different backup technologies, their price, ease of use and how they fails.

Then you must weight the pros and cons of each technology and make sure that the advantages of one technology will cover for the disadvantages of another. One technology might be fast and easy to use, but will not protect against a major disaster. That can be combined with one that takes more of your time, but can be applies less often, because a major disaster does not happen a lot.

Some of the upcoming posting will talk about such technologies, pros and cons.

Why 3 backups? - Risk analysis

2009-09-24T20:16:00.002+02:00

Some times you will hear that people make more than one backup copy why?

This is based on this simple risk analysis: At any time there is a certain risk that any copy will fail. If you have 2 copies and one fails, then you only have 1. If that fails before you can make a new 2nd copy, you will loose all of your data.

If your are on holiday or it is your backup that fails it can take quite a while before you notice it, and thus the other copy have much more time to fail. The longer time something has to fail in, the higher is the risk that it will fail.

A 3rd at another location will also protect against theft, fire, flooding and other major events.

Cheap and safe.

2009-09-17T20:17:00.007+02:00

No matter how you backup your data there is always the risk that the backup fails. In the time, from either your main copy or your backup has failed, only one copy of your data exists. If the other copy also is lost you have lost your data dispite of backup.

For this reason many copies of your most important data might be worth while.

Burnable DVDs are good for this, because they are cheap and can only be written once anyway. Select your most important data, so you can pretty much fill one or maby more DVDs.

One way of storing these DVDs are to put the newsest in a place outside of your house where you come often. That might be at work or at a friends house. When you visit some far away friends or family, bring one of the older DVDs and have it stored there.

Then, in the worst case you might not have all of the newest data, but you have most of your important data. And it is done for very little money.

Simple backup for everybody

2009-09-10T19:53:00.001+02:00

Here is a way of doing backup which will work well for most people:

Buy a USB flash drive and copy your data to that about once every month.

For some documents and pictures a 4 or 8 GB drive should do it. If you also want to backup some movies you should go for a USB harddrive.

Price

Very cheap.

Ease of use

Easy but requires some manual work. You don't have to set up any accounts, automatic schedules or technical stuff. Instead you have to do the work yourself and some people don't want to bother doing that.

You might want to use an online solution - wait for another posting about that.

Safety

Better than nothing. This solution will protect you against a crashed harddrive and damaged or deleted files. If you store the drive in another house (e.g. at a friends place) you will also be protected against theft, fire and other kinds of local natural disasters. Big scale disasters such as earth quake or massive fires requires that the drive is much further away. Consider an online solution or a "NAS friendship" - see upcomming posts for that.

What, why, how?

2009-09-03T17:38:00.003+02:00

What is backup?

Backup is making additional copies of data, in the case the original copy becomes inaccessible. In other words: Make a safety copy of your documents and pictures, so they will not disappear when your computer crashes.

Why

There are two kinds of people in the world: Those who have lost data and those who will loose data. You better have another copy when you loose yours.

Usually it is harddrives that break, but it can also happen due to computer virus, errors in programs, theft, water damage, fire, natural disasters and in many other ways.

How

Just make another copy of the data. That's it!

Well, depending on how you do that, you will get a cheap or expensive solution, which might be easy or hard to use and which may protect you just a little or very well. This blog is basically about those 3 paramters: Price, ease of use and protection.

Welcome

2009-08-27T17:21:00.000+02:00

This blog will contain a series of posts around the subject of backup - the act of making a safety copy of data. The earliest messages will touch on very basic topics and gradually get more advanced. This will be mixed with new thoughts around backup.