I have come here in the hope someone can point me in the direction of some answers/further reading.
Currently i am using a 1.5tb disk to store all of my multimedia and backups. I have now outgrown the size of my backups solution so it’s time for a change. The 1.5tb is nearly full but i am not expecting to outgrow this any time soon. It's mainly used for multimedia (integrated with my media centre)
Basically what will be the best way to back this up? I have been reading into the NAS/Raid solutions and think this is defiantly the best direction to go in considering i use this heavily for my media centre.
I think i need (please correct me if you have better ideas) a Nas solution that supports a RAID 1 configuration.
If this is the case i need a few questions answered,
- do i need to but identical disks? (go and buy a blank disk exactly the same as the one i currently own)
- can i set up a raid configuration with one full and one empty disk or do i need to format them?
- What other features should i be looking out for in my NAS?
Would a product like this be what I’m after? Seems to offer the RAID 1 configuration and a few quirky features.
RAID is not a backup. It protects against drive failure but not against lots of other risks.
For myself, I protect my data by dividing it into three tiers:
Active Files - these are folders that contain files that I work with every day and which change fairly frequently. I do alternating incremental backups of these every day and alternating weekly full backups, with one backup per month being stored offsite. The volume of these files is about 20-25GB.
Static Files - these are folders that contain files that mostly don't change - photos, music, reference material, etc. These are included in the daily incremental backups, but are fully backed up only once per month with the latest backup stored offsite. The volume of these files is about 150GB.
Archive Files - for the most part these are video files and installation kits which are quite large and which in a lot of cases can be re-acquired from other sources if I loose them. I keep two copies of these on two separate drives, one offsite. I swap the offsite and onsite drives monthly to keep them synchronized. Right now this volume of data is about 1.5TB. These files are checksummed and are verified monthly to ensure that all of the data is readable and correct.
If you have external backups covered and you're specifically worried about the downtime that a disk crash would cause, then RAID is the right solution.
My main point about the backup tiers was basically to note that you don't necessarily have to back up the entire 1.5TB all the time.
Checksums are values that are taken by reading every byte of a file and then applying a mathematical formula to them. The result is typically a string of a few dozen hex digits. The idea is that if any bit in the file changes, the checksum will be different, so if you store a copy of checksum of the file today then you can use it to confirm the file hasn't changed in the future.
I wrote my own checksumming utility, but there are a number of them available on the Internet. Typical checksum algorithms are "MD5" and "SHA1", and you can find programs by googling for these acronyms plus "utility".
I use MD5 - it's often criticized because of potential security issues, but in my case I'm not using it to secure information so that's not a concern to me.
> do i need to but identical disks? (go and buy a blank disk exactly the same as the one i currently own)
No, the disks don't have to have the same size, rotational speed, cache size, etc. But you'll be wasting some of the capacity and performance of the larger/faster drive if you use different drives.
> can i set up a raid configuration with one full and one empty disk or do i need to format them?
Not exactly sure what you're asking here. After you configure your two drives into a RAID 1 array, it will look like a simple disk to the operating system. There will be no indication that there are actually two drives behind that "virtual" RAID volume, and there is no way to put stuff on just one of the disks or the other - everything that is written to the volume will automatically have an identical copy written to both actual disks. That's the purpose of RAID 1.
You will have to partition and format the RAID volume in order to use it. As with any "real" disk, you have a choice of creating one partition to use all of the available space, or creating one or more smaller partitions which may or may not fill up all of the space.