Backup Options for a Small Company Prathamesh Datar, TAFE Petersham
Backup? • This report is designed for everyone and anyone who wishes to know how to keep their data safe and secure. • So you might ask what is backup? • You might have heard the term in movies.. • “Send for backup immediately”..And a whole police force arrives at the scene.. • Well Computer backup is not exactly the same
Data backup • In small business and office networks a lot of information is computer data and it is being created, downloaded and sent out all the time. • This data is the primary asset on which the company runs. So if this data is lost, the company will run into a state of financial or intellectual instability. • The copying of data into a single or multiple storage devices is called data backup. • This is done as a last line of defence against data loss.
Ok so? Why do we need it? • Ok, suppose that you are working on a project that is costing the company millions of dollars. • And suppose that due to some unfortunate circumstance, your data is lost or has been damaged. • So, you company indefinitely runs into loss or goes bankrupt. • Wouldn’t it have been clever to backup the data if it was so important onto a storage device so that even if it gets lost or stolen, you still have a copy of it.
Ok so is that like archiving? Or like a fault tolerant System? • No actually, but yes backup is sometimes confused with archiving or a fault tolerant systems. • Archived files are the actual or primary copies of a file, that are stored to be kept for future purposes unlike backup files which are secondary and are used if the primary data is lost or damaged. • Fault tolerant systems differ from backup systems in the sense that a fault in a backup system causes a data loss event while a fault in a fault tolerant system does not.
Ok, so how do we do it? • Backup, in plain words, is just copying data; like how you copy a file from one location to another. • There are four types of backups: • Full Backup • Differential Backup • Incremental Backup • Delta Backup • We shall discuss these types in the following slides.
Full backup • This kind of backup is the forerunner of all other backups. • In this backup, all files and folders are copied to an external media. • This backup is the easiest and fastest for restoring data. • But this backup takes up the most space and takes the longest time compared to other backups for mirroring the data. • And if the data on the external device is illegally accessed the thief will have total data access.
Differential backup • In this backup, data which has changed since the last full backup is stored on the device. • Hence, for total system restore, there are only two folders to restore, the full backup and the differential backup. • But the problem is that, if you do too many differential backups, you may result in copying the same two files into the backup folder. • This is because the system, will compare files in the full backup folder with the files on the system, and if there are changes it will copy that file. • So a file, changed after the first full backup will be backed up in the first differential backup and in the second one as well.
Incremental Backup • Incremental backup is also a backup like differential backup, that is done after a full backup. • But, instead of comparing files with the full backup, the files are compared with the last full, differential or incremental backup. • So, this backup takes only a fraction of the time taken for full backup and comparatively less time than differential backup for copying files. • But for restoring files, this backup take the most time.
Delta Backup • This technology, is not widely known as of yet. • This backup, is very similar to incremental backup. • Suppose, that in a 32 KB word file you change on letter. In incremental backup, the whole 32 KB file will get backed up. • But in delta backup, only that part of the document which was changed, will get backed up. • This saves a lot of space in the backup. But takes a long time to restore, because the backup is not at the whole file level, but at the level of what has been changed.
Incremental vs. Delta • Suppose that 256 character paragraph in a 32 KB file is continuously changed for 7 days with incremental backups and delta backups on each day. • At the end of the week, with incremental backups your backup space for that file has shot up to 2 MB. • But on the other hand, with delta backup the size goes from 32 KB to only 33.2 KB. • In this graph, the red bar indicates the incremental backup storage while the green indicates the delta backup storage.
So Which one Should I Choose? • First of all, backups are the last line of defence any organization can take for the protection of its data. • Because this sort of data recovery or data security is the least convenient. • But nevertheless it’s as important and should also be given priority. • Out of the four, the full backup is the forerunner and thus should be performed if you wish to do the other three. • So out of the remaining three, which one should I choose?
Comparison of all the three This is the hierarchy as to how I see the different types of backup.
What I would prefer • By taking into account the various pros and cons of the various types of backup, I would prefer either the incremental or delta types of backup. • And as there are 3 computers in the network the amount of data and the subsequent changes won’t be that large to require frequent backups. • A full backup every month, and delta backups every week, or every 2 to 3 days would be good way to keep data safe and secure. • And as this data backup doesn’t require much space, the company can save on storage space.
Ok, so where do I put all the data? • Typically there are three types of storage options when it comes to backup. • Pen Drives or Portable Hard Disks or Optical Devices like DVDs or CDs, or the newly released blu ray tech. • Network Storage Drives e.g. NAS or SAN • Online Storage
Local Storage • The first category which includes hard disk, usb drives, Optical disks etc. are all local storage options for backing up data. • These are low cost options as all backing up is done locally and is pretty easy to carry out. • The following slide shows the various types of local data storage options available and their cost per GB.
Local data storage options So as we can see there are various options available and the one I would prefer is the USB Hard Drive, as a single unit can hold nearly 2 TB of data and the cost per GB is quite good compared to the others.
Network storage Options • NAS and SAN are the two types of network storage options that are available.
What on earth are NAS and SAN?!!
Oh, sorry About that • Well, NAS is basically is Network Attached Storage where a NAS device is connected to a network of computers which backup their data on the NAS using a software which is already installed on the device which has storage up to a few terabytes. • But suppose if a company needs more than a few terabytes, say it needs 20 TB of data storage? • Then installing an army of NAS devices is pointless and ineffective. • In this situation, SAN or Storage Area Networks are used. But operating and maintaining SANS is not easy requiring professional knowledge. • NASs operate on TCP/IP protocols over an Ethernet cable technology. • SANs on the other hand use Fiber Optic Channel technology.
Diagrams of SAN and NAS SAN Network NAS Network
Network Storage Options I would see that a 2 GB USB drive can be used instead of a 2 bay NAS which would be cheaper too. But NAS can have more bays so if you want more storage it is an option. SANs provide a large storage space at a excellent speeds. So this is ideal for large computer network backups.
Online Storage • These days, with the invention of tremendous bandwidths and high speed data connections, you can store data in data centers around the world. • These data centers have storage devices dedicated to storing user data and allowing access to it on demand. • Many companies have started offering online storage facilities which provide advanced security and easy access to your data. • The following slide has various online data storage options.
Online Storage Options So online storage services can also be used. But you should understand that apart from these prices you will be paying for the internet connection. So, if you are on a limited plan, you should be wary of the uploading or downloading of information. And the costs can sometimes be severe. In the event of a full system recovery, all the data will have to be retrieved from the data center and thus downloading of a large size of data is inevitable. So it is better to use this storage option only for the most important files that you must backup leaving the rest to be backed up on the local storage devices.
So what do we conclude? • From the various slides and research I have come to show you in my slides, I reached a conclusion as to what backup storage network would be best for your company. • I would suggest a 2 TB USB drive which would be locally used between the three computers or used on a network with an Ethernet bridge so that all three computers can access it. • The backup option I would prefer is the incremental backup as it’s backup rate is fast and has a faster restore rate than delta backup.