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Discussion Starter · #1 ·
First off, thanks to everyone who's contributed to the great guides on the NAS subject here. It's been really, really useful to me as I prepare to purchase and setup a NAS.


I'm looking at either a 2x2TB or 4x2TB NAS, probably either QNap or Synology at this point, and although I've read the "NAS isn't backup!!!" thing multiple times, it seems like RAID technology does serve, in some respects, to provide backup. Now, I understand if my apartment building implodes or fire destroys my city block that without external backup stored in my external bunker my data are gone regardless. I'm betting that won't happen... I also imagine that an internal NAS failure of some sort could jeopardize all of my data, but I would think that most/much of the time that data could be recovered in a new NAS unit (so long as the drives are intact). That being said, in a 2x2 setting with RAID 1/mirroring the 2nd drive is, in effect, backup, but that leaves only 2TB of actual space. In a 4x2 RAID 5 setting, however, I'd get 6 TB of usable storage space, correct? And as long as only a single drive bites the dust at one time (and I replace it and rebuild the array promptly), right?


It seems like then that there is inherent "backup" (except for fire, etc.) in a RAID5 setup so long as you replace anything quickly that goes bad. I guess I'm wondering outside of full-on catastrophe what are the chances of a full system data loss from a RAID 5 setup? Does this happen somewhat routinely or is it as rare as I would think (I'm planning on going pretty top-end NAS and drives...)? Should I still try and make sure I have a functioning 6TB backup for my NAS?


Thanks again everyone,

Jon
 

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Quote:
Originally Posted by jcfay /forum/post/0


it seems like RAID technology does serve, in some respects, to provide backup.

first off... stop saying backup... there is nothing about raid that is a backup...


now raid does offer the convenience of if one drive fails, you can conveniently restore it... but that is it... it is no backup...

your actual DVD's are your back up (assuming you don't mind spending hours/days/months re-ripping them)
Quote:
Originally Posted by jcfay /forum/post/0


but I would think that most/much of the time that data could be recovered in a new NAS unit

only if that unit is exactly the same in every way... same model, same firmware, etc... of course at this point you could also put in more drives and use the 2nd NAS as your backup

Quote:
Originally Posted by jcfay /forum/post/0


And as long as only a single drive bites the dust at one time (and I replace it and rebuild the array promptly), right?

this applies to every RAID, but yes that is true... as long another drive doesn't fail in the rebuild process you are fine... of course the rebuild process is murder on drives... so if any of the other drives are of the same general age, the rebuild process may very well kill them... and then all your data on all the drives goes 'poof' and you go grab your DVD's and start ripping again...


Quote:
Originally Posted by jcfay /forum/post/0


I guess I'm wondering outside of full-on catastrophe what are the chances of a full system data loss from a RAID 5 setup? Does this happen somewhat routinely or is it as rare as I would think (I'm planning on going pretty top-end NAS and drives...)?

I have 2 infrant ReadyNAS NV+'s never had a problem with either... one did warn me that a drive might be going bad... so I replaced the drive and rebuilt just to be paranoid... but other than that they have been rock solid for ~5 or 6 years now... could be longer, I have lost track...


note: I would not recommend the NV+'s, just because they are such an old model, but I would recommend ReadyNAS in general as they have been just great...


another thing you may want to look at is unRAID , you get the same single drive failure recovery convenience as RAID, but you get a bunch of other goodness as well:
  • the drives don't need to be the same size, so you can add drives as you need them, replace small drives later with bigger drives, mix and match what you may have laying around, etc...
  • the data is not striped across multiple drives, so if anything 'bad' ever happens you can always pull out any undamaged drives and get the data off them... you only lose the data on the 2 (or more) bad hard drives... and you may be able to recover some of that too, depending on how 'bad' they really are...
  • supports up to 20 (or 22? I forget) drives if you really want to go crazy...
  • not all the drives need to spin up at once, only the drive with the movie you are watching needs to spin up... good for the electric bill$ (especially with 20 drives
    )
 

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Hi Jon,
Quote:
Originally Posted by jcfay /forum/post/19608197


I guess I'm wondering outside of full-on catastrophe what are the chances of a full system data loss from a RAID 5 setup? Does this happen somewhat routinely or is it as rare as I would think?

It is not as rare as you might think. I found out the hard way.


I had a power-supply go bad in a raid system, and it took out every drive in the computer. Luckily, the important data was RAID-1, and I was able to recover it by having only one drive repaired by a very expensive data-recovery service.


It turns out that the recovery service makes most of their income recovering the data from failed RAID systems.


My NAS now backs-up all important data to a 2tb USB drive automatically every night. That doesn't include movies and music, as I have the original optical media for backup.
 

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Well if we are splitting hairs, RAID 5 is neither a convenience or a backup, but is a level of fault tolerance; the fault in this case being drive failure. Not fault tolerance from a power supply failure, CPU failure, memory failure or multitude of other things that can fail. If you want more fault tolerance, EMC, HDS, HP and others would be happy to cash your check.


If your data is really valuable or important, offsite storage of your backups is essential. But beyond what most of us want to keep safe. RAID does nothing to protect against someone removing all the data by hand, for example.


If my RAID 5 volume fails, I have the inconvenience (lol) of having to recopy a few hundred movies, but at the end of the day will incur no expense beyond what is necessary to get the storage back online.


That out of the way, a NAS is a great way to serve media in your home.


RAID 1 is great for 2 disks, but when you have more spindles, RAID 5 and 6 will always be equal to or more space efficient while still providing some fault tolerance. The problem with a 4 disk striped/mirrored setup (data striped across 2 disks, then mirrored to the other 2) is that while yes you can lose 2 disks, they have to be in the same striped group. If you lose one disk in each group, you are still dead in the water. RAID 6 can lose any 2 disks in the parity group.


FYI I have a Netgear RNDU4000, and it is great. What I am finding it that once full, it needs very little CPU, so a lower performance 4 disk unit like the Thecus N4100PRO would have served me as well, while leaving a couple hundred more dollars in my wallet.


I am considering buying the Thecus, and putting it behind the Netgear using NFS, using it to present movies while new stuff is written to the Netgear.
 

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Quote:
Originally Posted by 98_1LE /forum/post/19610606


Well if we are splitting hairs, RAID 5 is neither a convenience or a backup, but is a level of fault tolerance; the fault in this case being drive failure.

If we are being picky, it is being Single drive failure assuming raid 1 or 5 (raid 6 & 10 would be 2)... and at the end of the day, that is a convenience vs re-ripping everything...


but still not a backup...
 

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Somewhatlost gives some good advice. My own 2₵ is to buy a 6 or 8 drive NAS that allows for a seated hot spare. This way if an HDD dies the NAS will shut down the dead drive and automatically initiate the hot spare so you lose no up time at all. Then all you need to do is replace the dead drive and it becomes the new hot spare.


If it helps I've got 2 ReadyNAS NV+'s myself and a QNap 859 Pro+. They're all great machines, but the QNap is several years newer, with a much better interface and specs. The QNap has over 14TB of storage and holds everything I need at the moment while one NV+ acts as a local backup of important files (not movies or music, just documents, personal videos and photos) and the other NV+ is off-site at a family members home acting as a remote secondary backup. This may seem like overkill, but there are many files (financial docs, family photos, etc.) that would be devastating to lose. Videos of my children's first steps, photos of my late grandfather, etc. cannot be replaced if they're lost due to catastrophic failure or a fire.


As for the title of this thread, nearly ANY modern NAS would make a great home media server, the QNap plays nice with my XBox 360 and HTPC, so I don't think you really need to worry too much on that front. Just buy a NAS with the most drive bays you can afford, or better yet, TWO of them, and have at it!
 

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Well there are sites that specialize in this and people here who know a lot about Raid. I would get a WHS, not use drive duplication and hook up a Drobo or whatever to the WHS which would back it up. The WHS underlying OS supports GPT drives so you wouldn't have a 2Gig issue and you would get the advantage of Raid like from the Drobo. The big advantage of a WHS is you can read the disks on standard computers. Raid (and Drobo of course) systems are proprietary and once locked in you don't move around that easily.


I like my Acer H340 but the HP WHS units are probably better ( and more expensive). You can easily expand the WHS server via esata with the right model.


Netgear, Synology, Qnap, etc... all very good but do you really want to maintain a data centre?


philip
 

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Quote:
Originally Posted by pmcd /forum/post/19618349


The big advantage of a WHS is you can read the disks on standard computers. Raid (and Drobo of course) systems are proprietary and once locked in you don't move around that easily.

In general, this is true.


However, the drives in my Synology are configured as RAID-1 with an EXT3 file structure. I can take a single drive (only because it is RAID-1) and connect it to any Linux machine and access it as a normal Linux drive.


I don't know how common that is. And RAID-1 certainly isn't the most efficient way to store your data.
 

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AFAIK other than Veritas/Symantec volume manager ($$$) or RAID 1, there are no portable multi-disk striped volume management that is portable.


Can one create a RAID 6 volume in WHS, pull the disks and pop them into another WHS box, and it will be able to determine the structure of the volume(s) and mount it(them)?


I have used Veritas at work for almost 10 years now and would love to have it at home, but cannot afford/justify the cost.
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by MarkHotchkiss /forum/post/19618522


In general, this is true.


However, the drives in my Synology are configured as RAID-1 with an EXT3 file structure. I can take a single drive (only because it is RAID-1) and connect it to any Linux machine and access it as a normal Linux drive.


I don't know how common that is. And RAID-1 certainly isn't the most efficient way to store your data.

Thanks everyone. Really appreciate the input. My impression of any RAID NAS was that it was accessible and easily manipulated from my windows machine - Qnap and Synology's software emphasize the multifaceted ability of their NAS machines. I'm a bit concerned, however, if a RAID volume is problematic to access (to someone used to working on a desktop, etc.). There is a lot of learning to this process for someone new to all of this, that's for sure, and I'm sure I'm going to need to get more familiar and facile with FTP, etc., but I'm hoping the Synology will do the trick. Am I missing something here or is access tricky with these sorts of setups?


Thanks for the links to the WHS and Drobo machines. I'll have to look at some of the backup options. Just hoping the Synology which should arrive today wasn't a mistake as a home media server and mass storage/streaming device...



Thanks again guys
 
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