Data Survival: NAS, RAID, etc.

Ok, long story short, purchase a D-Link DNS-320 Network Attached Storage device as a central storage location and backup for my home network. This model can hold two drives.

I will make periodic offsite backups, but I was attracted to the option to set this up as RAID 1. I understand the main benefit of RAID 1 is that if one HD fails, the other one keeps working seamlessly. What is not clear is what happens if the RAID controller hardware fails?! Can I take a HD and plug it into andy computer or external hard drive enclosure and read it? Or do I need another RAID controller? Or do I need the SAME RAID controller?

In other words, if I don't absolutely need uninterrupted service, should I set it up as RAID 1 or just two normal seperate volumes? I could then theoretically manually back up one drive to the other and remove it for offsite storage...

The other options are: RAID 0 (which is faster but doubles the likelyhood of total failure) or JBOB (two drives look like one big one, perhaps with the same drawback as RAID 0). I don't think I want either of those.

Thanks.

Since the D-Link DNS-320 uses SATA drives, you would be able to connect your drive to any computer that has SATA connectors. How easy you would be able to retrieve the data would depend on your security setup on that drive.

Jeanette Isabelle

But doesn't if matter how the drives are formatted / what the operating system is? It look like many of these devices use a Linux based operating system. I'm running XP now, and probably also Windows 7 soon.

It depends more on the file system than the operating system. Linux is able to run on a number of file systems. If it is using the Journaling File System, you are in luck. I have accessed data from that file system with Windows. If it is using a different file system, you still may be able to boot from that drive.

Jeanette Isabelle

With most types of RAID, you need to have the same type or at least a very similar RAID controller, configured correctly, to recover the data.

With RAID-1, straight-up mirroring, this is generally not the case, you can plug the drive into almost any other controller and expect to get the data.

Keep in mind that while RAID is great in protecting against HDD failure, it does nothing to protect against malice, human error, and many environmental issues.



Manual backups are severely subject to human error and failure to follow through. I'd suggest an online backup service like Carbonite (my only connection with them is as a satisfied customer).

One last note of advice. There are several scenarios where the drives AND the controller can be destroyed. If you have critical data, you need to have another copy of that data offsite on a different medium. This will cover you if you have a fire, theft, electrical surge, or other event that completely wipes out all the data in your house.

+1 to online backup service

link to online backup comparison site (I am not a vendor/sales , etc)

http://online-data-backup-review.toptenreviews.com/

I have used both mozy and sugarsync, and have been happy with both.

Thanks everyone for the info and also the comparison site. The online backup decision is going to take some additional study. Backup is a more complex issue than it seems at first.

Some files, like family photos, are irrepaceable. Some are updated often, like my budget spreadsheet. Others are created once, then stored unchanged forever, like tax returns.

I'm planning on using the NAS mainly for shared media storage (mp3's & movies). These files are not really irreplaceable.

I see that Carbonite, for instance, has unlimited backup but only for files that actually reside on your local hard drive. Some services charge by the Gig. Either way doesn't seem practical to have online backup for everything.

Ok, I think I'll get two 2Tb drives for the NAS and configure them as RAID 1 for some bonus redundancy. I'll store or at least keep a copy of all irreplaceable files on a PC and protect them with online backup service.

I don't like the lack of privacy of online backup services. Theoretically, your data is accessible by employees of the company and who's to say that their security is good enough to keep out hackers.

I have a similar setup to yours. I use RAID 1 to backup my data at home. Once a month (sometimes more frequently) I use "Beyond Compare" to move any changed or new files from the RAID onto an external drive and carry that external drive to my office where I lock it up in my desk. The Beyond Compare routine only takes a few minutes depending on how many pictures I've taken lately. I can also perform this task from my office by remoting into my home computer but it takes longer so I don't use this method usually.

I also have everything divided between encrypted and non-encrypted areas of the disk. Photos and information PDF's, ebooks, and music are unencrypted, and I use Truecrypt to section off a part of the disks for private files like business planning ideas, tax forms, birth certificate, etc.

With this setup, I feel like I have much more control over my backups, the backups are more secure, I save some money from not paying for an online service and I have a lot more space available than online services offer.

I also have remote access to my home computer via the LogMeIn program while traveling, so if there's a file I need I can get to it much the same as using an online service. In fact, I keep very few documents on my laptop. I just use my phone as a broadband modem and remote into my home computer quite frequently to access whatever I need.

If this were the only concern with online backups, it seems you could just encrypt the data. It would be a bit of a hassle to access it afterwards, so inconvenient for stuff you use daily, but for backups (which you create once and then very rarely use) it could be OK.


One drawback is that these backups are within relatively limited geographical area, since your work is probably relatively close to your home. So it's conceivable that a large enough earthquake or flood or a riot could destroy both locations. Not sure how much of a concern this is in KY. With online backups, you can distribute over a much larger area.

A general concern with any sort of outsourcing is how much and how long can you depend on the provider to be there? Lots of companies go from all is good to completely gone in the blink of an eye. What happens to your data (and your recovery plans) then?

Some specific concerns for outsourcing data storage: Is the server farm you are backing up to (some where in the land of tubes) actually redundant? Does the company have a mirroring / internal offsite backup approach? How often do they test their recovery process from full or incremental backups?

I don't have the fastest network connection in the world so, I have stuck with copies on hard drives for critical data (not really all that much space compared to all the stuff filling my hard drives) and some reasonable protection of the backups (one onsite in "hardened storage" - a fire safe, and one at work a mile or so away). That covers the likely scenarios I need to worry about while having a laptop covers most of the rest of my concerns.

Good luck finding what works for you.

- Eric

Well, I finally got around to watching a film I recorded onto my PC called AI, after looking at the Digital TV card folder (from a old Hauppauge DEC 2000). Then I noticed the date it was recorded, 30th December 2004.

Is there really any point of having vast libraries of video and photos etc if you never really get around to watching them. I would just put all your critical data on a enterprise USB flash drive. Does you NAS enclosure have a USB port to backup to a portable drive?

Recordable DVD also is worthwhile as even many BluRay and DVD players will also display photos, music etc

WD Velociraptor HDD drives have MTBFs of around 1.4 million hours i.e. around 4-5 times that of other HDD drives and many SSDs will have MTBF of 1 million hours.

As far as movies go, I would agree except that the kids have videos that they watch over and over. And they are MURDER on DVD's. They also have a huge pile of VHS - I'm going to capture the ones they actually watch as they watch them. Perhaps most people don't have this issue, but I have seven (7) kids. By the time something has been handed down and outgrown by your 2.5 children, mine aren't even half way through with it.

Further, we don't have cable and or decent broadcast TV reception. Everything we watch is either on media or streaming from Netflix, PJTV, EWTN, Youtube etc. The next project is add another computer that will be our new "TV". For the life of me I can't figure out if I should get the biggest monitor I can afford or buy a "real" tv to use as a monitor.

You can either encrypt before backup or (with Carbonite) manage your encryption key yourself. If you manage your own encryption key, they cannot recover it or your files if it should become lost.

For myself, I encrypt a few critical files.



Truecrypt is outstanding.



I would worry more about my LogMeIn credentials being compromised than Carbonite getting hacked.

I worry about that too. I keep a close watch of my firewall's logs and I change the password often and use some really long pass phrases. Over the past 10 years I haven't had any problems, knock on wood.

Have in mind though, that many free online storage services do not allow any encrypted content.

I'm also using a RAID-1 NAS for the important documents storage, which is duplicated to other 2 external drives periodically. I have it sitting openly on the table, so I can grab it and take out in an emergency.

Well, I now have a pair of WD 2TB "Green" drives set up as RAID 1. I chose the "green" version because they ought to run cooler and therefore more reliably, and speed is not of the essence.

I'll let you know when I run out of storage. Thanks for the advice, everyone.

One last comment - I have the DNS-323. If the NAS itself did fail, you should be able to mount either drive in a Linux host as they're formated for ext2 (or ext3, depending on which firmware you're using).

If a Linux is not available, you could consider using a Bootable LiveCD or Live USB Key running Fedora, Ubuntu, or whatever else you're comfortable with.

Actually, if you want the best reliability, there are two version of each drive. The consumer version and the enterprise version. The enterprise version of green is supposed to be more reliable and better for RAID use than the consumer version of green.

Otherwise, consumer grade Blue, Green, and Black, are supposed to be equal in their reliability. The difference between them are things like power consumption, speed, cache, and, of course, price.

Hmmm. I also have the DNS-323 and had not thought of that. I was thinking I would be able to plug one of the drives into my SATA to USB adapter, run power to it, and plug it into my Windows machine. I guess that won't work.