What is a Backup?
From SynologyWiki
| Because of the increased discussion and ambiguity with what is defined as a backup, this article was created to help and to briefly discuss what a backup is, and its definition. According to Wikipedia, a backup is defined as: In information technology, backup refers to making copies of data so that these additional copies may be used to restore the original after a data loss event and restore small numbers of files after they have been accidentally deleted or corrupted With that being said, having a backup of data by definition means that there is at least two copies of data, at the very minimum. Of course, more copies that exists, and having those copies spread across the entire world increases the chances of data survival. Of course, having more backup copies of data often means increased complexity, management duties, and cost of resources to support the backup network. |
Backup Technology
A basic overview of the current SMB/SOHO technology that can be used for backing up
RAID: This is not a backup system; this cannot emphasize this enough. RAID is designed to protect the user against hardware failure of the HDD, and allow the merging of HDDs into one larger volume. However, placing all of the data onto one volume does not constitute it being "backed upped" because there is only one copy of the data, and it's in one location. For this to be effective, another RAID machine will have to be used, with the identical volume capacity of the primary server, which will resulting in minimum two copies of data, assuming that one volume will mirror to another. Of course, using independent UPS system is recommended in this case.
DAS: Or Direct Attached Storage (external HDDs) performs one function only, which is to expand storage capacity or backup the data of the client it is attached to. Synology products can utilize a DAS to backup data, via Local Backup.
Optical Media: There are many competing optical storage mediums out there, great for carrying a large amounts of data in the 120mm Disc. The down side with using these discs is long term storage, as these discs organic dyes will eventually fade away, and the optical disc layers will begin to peal away. The best way to use writable optical media for long term archival storage is to store the media in a moisture proof bag, remove all the air in the bag and place the entire bag with optical disc in a cool and dark place, such as a safe, kept at 20C.
Cartridge Magnetic Media Drives: such as Tape drives, Iomega Zip/Jazz Drives to name a couple, are capable of having high sequential performance and has an economical price per cartridge. The concern with using Cartridge-based media is that lacks automation and requires human-intervention to replace or update the cartridge.
Backup Methodology
Having all of the data placed on a modular device, such as one of the devices listed above, as a primary data storage does not constitute of having the data backed up. While yes, the data is on a modular system, where it can be easily be removed from the premise to save it from physical damage (fire, flood, vandalism, etc) it does not protect the data against viruses, accidental deletion, data corruption, intentional damage, hardware failure, malicious software or other misuse. In general, there are many ways to approach data backup; however at the very minimum, users are recommended to have at least two copies of their data, even if it is on site, it's better than nothing. If the data can be kept offsite, that would be better. For on site backups, the Synology Server supports the following methods.
Windows Client Backup
Using Synology's Data Replicator 3, Windows users can backup their files from the PC to the Synology Server; thus ensuring two copies on site; one on the Windows computer, and one copy on the Synology Product.
Windows Remote Client Backup using rsync
Remote Windows users can backup to the Synology product using a Linux Protocol call rsync. This offers great benefits for heavy mobile users or users who do not have local access to the Synology server. These users can continue to have their data backed up to the Synology product.
Local Backup
Using an External HDD, attached to the Synology server, it will automatically backup the data from the Internal HDD of the server, to the external HDD attached to the server. This entire process is done internally of the server; does not require a client computer to control the backup process.
Network Backup
Using the above process will replicate the data from one Synology Server to another Synology server via LAN or WAN. You can use a combination of any server, as long as the receiving server has enough storage capacity. One example of this is to have a CS407 with 4x500GB of HDDs in RAID 5, and have that system back up to a DS207, with 2x750GB HDDS in RAID 0. This will work just fine.
rsync
The Synology product supports using the rsync protocol, a popular Linux program, to backup data. Using rsync, data can be backed up to and from the Synology server to other clients using the rsync Protocol.
Final Notes
In general, using any combination of the above will insure that data is backed up in one way or another, using more combinations will increase the chances that data will survive should the infrastructure suffer a critical failure. A recommended course of action for Small Businesses is to have two copies on site (User Computer + Synology Server) and have another copy off-site (Another Synology Server) such as at the owner's home or another office. While on the subject of backing up data, one should at least practice how to restore data using the restore wizards, so the process is familiar and easy to execute.
Additional Links
Forum Discussion
Smart SOHOs Don't Do RAID, Tim Higgins, SmallNetBuilder
The Tao of Backup, a good story on seeking enlightenment with regards to backups.
Wikipedia:rsync, Background information about rsync
