Disclaimer: I have had a ReadyNAS (of one sort or another) for 7 years now.
The main reason I purchased mine? I wanted to ensure my data could survive a DRIVE FAILURE.
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I am very tired of "hard-core-enthusiasts" constantly re-proclaiming "a NAS is *not* a backup solution".
REALLY? What is the definition, then, of a backup (aside from "a second copy")???
a) I have my critical data on my PC b) I store my data elsewhere, IN CASE MY PC DIES
>> In other words, my data is arranged such that it can survive a hard drive failure. Pure and simple.
Lets expand on this: I have spent numerous hours (hundreds!) converting my CD collection to 320-bit MP3, and DVDs to DIVX MP4. I can replace the files, but my time was valuable. My photos, more valuable, are on my PC, my wife's laptop, AND the ReadyNAS server.
However, if a single drive dies - I replace it. I have not lost data. That is a backup. Lightning struck (one drive died), I survived (I had RAID). I am absolutely OFFENDED by all the "puritans" that say a RAID is not a backup. A backup is meant to survive a single point of failure.
OK, if a meteor strikes my house, I lose my data. However, my data is on my PC, my laptop and my RAID-5 server. In a meteor (or fire), ALL ARE LOST - despite 3 copies of my data. Same with theft, flood, etc - since shiny computer-things are attractive stealing stuff.
Therefore, RAID-5 *AND* backup only protects against... hard drive failure. Since, backing up your drive to an external **IS** considered a backup -- then, backing up your data to a RAID-5 array is **BETTER** than a backup.
(no, I care not about "accidentally deleting stuff" -- we have "recycle bins" and "Norton Recovery" stuff, so irrelevant).
RAID-5 is a backup. Not meteor proof, but reliable. End or argument.
I am very tired of "hard-core-enthusiasts" constantly re-proclaiming "a NAS is *not* a backup solution".
REALLY? What is the definition, then, of a backup (aside from "a second copy")???
a) I have my critical data on my PC b) I store my data elsewhere, IN CASE MY PC DIES
>> In other words, my data is arranged such that it can survive a hard drive failure. Pure and simple.
I don't like it when someone says something like "a NAS is *not* a backup solution" without qualifying that statement. If data is stored primarily on another device, then a backup copy stored on the NAS is a backup. However if the data is primarily stored on the ReadyNAS, then you need to make a copy some place else for it to be backed up. So, a backup is a second copy of your data stored on a separate device. Preferably a backup solution will involve keeping copies of all critical files in multiple locations (i.e. at least one backup copy off-site) at all times.
zamboni wrote:
Lets expand on this: I have spent numerous hours (hundreds!) converting my CD collection to 320-bit MP3, and DVDs to DIVX MP4. I can replace the files, but my time was valuable. My photos, more valuable, are on my PC, my wife's laptop, AND the ReadyNAS server.
However, if a single drive dies - I replace it. I have not lost data. That is a backup. Lightning struck (one drive died), I survived (I had RAID). I am absolutely OFFENDED by all the "puritans" that say a RAID is not a backup. A backup is meant to survive a single point of failure.
The RAID is not the backup in itself. Redundancy and backup can easily be confused for being the same thing. Redundancy or high-availability refers to a single component failing in a system but the system remains online. For example you could have e.g. a hard disk, power supply (if you have a dual power supply NAS) etc. fail but the system remains online.
A backup on the other hand is stored on a separate device to the primary copy. It tends not to provide immediate failover and generally needs to be restored manually. This protects you against things like accidental file deletion, file corruption etc. A backup also tends not to be entirely up to date. It could be a day old perhaps or longer depending on your backup schedule.
Also take a look at Preventing Catastrophic Data Loss. It's a very useful article to read. One common misconception is that often users think that they can pull a drive from a RAID-1 array and treat this as if it were a backup!
zamboni wrote:
OK, if a meteor strikes my house, I lose my data. However, my data is on my PC, my laptop and my RAID-5 server. In a meteor (or fire), ALL ARE LOST - despite 3 copies of my data. Same with theft, flood, etc - since shiny computer-things are attractive stealing stuff.
That's correct. That's why some go so far as to say a backup is a copy of your data stored at a separate location (i.e. off-site) to the primary copy.
zamboni wrote:
Therefore, RAID-5 *AND* backup only protects against... hard drive failure. Since, backing up your drive to an external **IS** considered a backup -- then, backing up your data to a RAID-5 array is **BETTER** than a backup.
Yes. Having redundancy on your backup is better than simply backing up to a USB drive.
zamboni wrote:
(no, I care not about "accidentally deleting stuff" -- we have "recycle bins" and "Norton Recovery" stuff, so irrelevant).
There's still the possibility your memory module fails and you get data corruption. Or you try a beta firmware and things really get mucked up badly (I don't know of any cases of this, but it's possible). Things can go wrong when data is stored on a single device. Unlikely but it's still a possibility.
zamboni wrote:
RAID-5 is a backup. Not meteor proof, but reliable.
Redundancy isn't the same as a backup. It's good, but it's no replacement for a backup. If you backup the data from your PC to a NAS, then your data is backed up, no matter whether you're using a striped RAID-0 volume (large risk you'll lose your backups) or RAID-5 or RAID-6.
Most businesses store there data on a RAID array and they realise that simply storing the data on the server does not mean it's backed up. They may not know that the server uses RAID, but even if they do, their IT advisor should be able to explain this to them and explain why backups are important.
zamboni wrote:
End or argument.
RAID (Redundant Array of Independent/Inexpensive Disks) by definition is talking about redundancy not backups. It is not designed to backup your data. Having multiple copies of your data on a single device is redundancy, not a backup. Storing data on multiple devices is a backup.
An individual has to decide for themselves what their aversion to risk is and how they should backup their data. For those with huge amounts of data it may be impractical or not feasible to backup all data. However irreplaceable data should be backed up both on-site and off-site. Some other data you may just have on-site backups of (if not concerned about losing data due to fire, theft etc.). Still other data you may just store on a RAID array (e.g. NAS) - typically this would be data, that may be able to be recreated/reobtained or is too expensive to backup (huge amount of media files). Data of even lesser importance may be stored on a single hard disk and not backed up.
On rare occasions it can be useful to deal with a problem by doing a factory default (wipes all data on NAS). It can also be an important performance troubleshooting step. So sometimes someone can ask if you have a good backup before suggesting a factory default be tried.
A very good discussion. And covers all the details, but lets look at data protection from a strategic point of view. Unfortunately the vast majority of computer users have no concept of what we are talking about, and are unconcerned until they join the lost data club. I joined the club in 1984, not with a disk hardware failure, but somehow the FAT on my hard drive got scrambled and the directory was gibberish and the files inaccessible. So, I started backing up with a backup program to diskettes (5 1/4").
Later rather than use a proprietary backup program, I would simply copy the files over to a CD then DVD then to a second HD. None of it was really a good solution, because it was done manually and as it took longer and longer, I was less and less reliable in doing it.
To me there are three lines of defense in data protection (hacking is not part of this as that is another problem). The first line of defense for me is the redundancy factor in my NAS. All of my permanent data resides on my NAS. I will download some files that may be on the PC but almost immediately the data is either moved or copied to the NAS. (Copied if I still want a doc on my desktop for ready access for example).
Now this only protects me against a single drive failure (4 bay, single redundancy only). If during or before I replace the drive, a second drive fails, then as the Marines say, "Tango Sierra".
The second line of defense is the second, separate copy of all the data. In my case, NAS2 which is rsynced to NAS1 on a nightly basis so all the shares are exactly duplicated. I have actually had to use that copy on occasion when I have messed up a file on NAS1, so I can go back to the original on NAS2 and copy it back to NAS1. BTW - it is not good practice to perform operations on files on the second copy, simply copy the file to the first device, then perform the operations.
You can learn from the mistakes of others, and a classic that occurred years ago in the company from which I retired, was that they messed up the Accounts Receivable files for a plant, so they removed the original disk pack and inserted the backup (years ago, ancient technology) and performed the same operation which again messed up the backup AR files. (Application error) Tango Sierra big time.
But as zamboni said, when the meteor hits the house everything (including NAS1 and NAS2 are gone). While we may smirk a bit at the concept of a meteor hitting hitting (I think there is a cloud backup commercial like that), the folks in Mississippi, Alabama, NW Georgia, Tennessee and Virginia, last week fully understand the work catastrophe for hundreds of thousands are living it right now. Even putting the off site in another building on the property or next door or even a block away might not be satisfactory. A year ago the pipeline rupture created a similar catastrophe on a limited scale. Those who survived only had seconds to react and no time the grab the NAS and run.
The third line of defense, the most difficult, is the off site backup. My critical financial info and photos are on a small USB disk in my SD box at the bank. I update it on a routine basis by alternating drives. (Bank is 30 minutes away). But this leaves out the Terrabyte of video files I have. I need to work on this solution myself.
As this link explains, even professionals can screw up on occasion. There's that old Tango Sierra again. I need to really get my third line fully up, I even have the hardware (semi-idle NV+) to do it with. I just haven't done it.
Zamboni - we beat the drum about backups because too many members still don't have one, or confuse redundancy with backup. Then when they suffer the dreaded two drive failure, or a "corrupt root" it is Tango Sierra. Sometimes the data can be recovered and sometimes it cannot. Having all your data on one device is a terrible idea, having all your data in one physical geographical area is a bad idea. I personally can only remember a hand full of instances when a member posts with a problem and has a current and complete backup. Since you have a backup, just nod when you see us beat the drum for backups, for unfortunately, you are in the minority of the NAS users.
As mdgm has pointed out a factory default cures a lot of ills, but it does of course wipe the data. Not a problem with a current and complete backup.
Very good posts! I guess I mean that, to me, the next safter thing is off-site.
I've had drives die over the years, sometimes taking some data with it (fortunately, they were also sometimes just the OS drive, not data - so an inconvenience).
Thus, a RAID protects one against the horrible scenario where a drive failure robs you of photos, etc. The chances of dual-drive-failures (before I can replace the first) are less than my house burning down.
When people talk about backup - it is backing up the files to another device... generally in the same place (not offsite)... meaning the data is at about the same risk because a meteor or fire or robbery would probably lose both.
I keep all my photos on my PC, my NAS, and I put a 2nd drive in my wife's 17" Dell (since it nicely had 2 drive bays!). Both her drives are encrypted with TrueCrypt - and if we are out of town, it is usually with us.
Perhaps "backup" is too generic of a term because there are different levels. RAID is a backup against a drive failure, just like copying files to a USB hard drive, but "offsite backup" is a different level entirely. But I'd trust my data more to a RAID array than to my PC with a copy on a USB drive -- because the ReadyNAS is far more self-monitoring and alerts (when it can) when it perceives a drive might be starting to show signs of failure.
It is those alerts that are important. When it started warning me about my 1.5TB's, and I replaced them and tested the drives in my PC, it got me to start looking at my own PC drives... and, sure enough, my OS drive fails DST. There's no reason Win7 shouldn't be nicely informing me of this.
Thus, I stand a higher chance of 2 drives in my PC dying than 2 drives in my ReadyNAS. It is in this way that a RAID is a better backup than 2 drives in a PC, which everyone would agree is "backing up your data".
I take the statement "Remember a NAS is not a backup" to be a reminder to the less technically knowledgeble that a NAS is part of the answer but not THE awnswer.
A virus, operator error, equipment malfunction, electrical spikes or theft could easily cause loss of data on a NAS without a catastrophic event at the building where it is housed.
In recent time we have seen catastrophic events at buildings that would cause data loss (tornadoes, flooding in Australia, and Katrina (search for Katrina in this forum for examples)).
I also suggest that the definition of a "backup plan" changes with the available technology. In the good old days, few people made duplicates of their photographs (especially slides). It was difficult, expensive and produced an inferior product. As times have changed, unsophisticated users have changed the backup media they use from floppy, to tape, to CD/DVD to USB hard drives or similar. The method of transferring the data has changed from physical copy to a more automated process such as a backup program thus increasing the probability that a current backup exists at the time of the event.
As we become more reliant on technology, through more and more data existing only in one place and in only one form, we have more to loose. We live in the age of electronic albums, digital video and professionally I am moving closer to the paperless office, where I will no longer have a paper file to rely on. In such a world, I need a "backup plan" that covers more and more of the possible events.
In my opinion, while the hardware and software for Readynas Replicate is not cheap, it has reached a point where the costs are reasonable and provides the safety of offsite storage and versioning history and so the definition of a "backup plan" should now include automated offsite storage. As bandwidth becomes cheaper and importantly as Replicate does not require any configuration of the router at the remote end, it is easier to convince family or friends to house your backup device and for me to do the same for others.
In the future Readynas Replicate may be replaced with Readynas Vault, but at the moment Replicate is for me the way to go and the basis for a proper "backup plan".
Perhaps "backup" is too generic of a term because there are different levels. RAID is a backup against a drive failure, just like copying files to a USB hard drive
"Backup" is only too generic a term when you redefine it to mean whatever you wish as you appear to do. Lookup "Backup" in any dictionary and it will refer to creating a 'copy of data to guard against loss'
RAID does not create a copy of your data and so fails to meet the definition of being a backup. Even RAID-1 fails to meet this definition as it does not protect against data loss in the form of accidental deletion.
RAID is also nothing like copying files to a USB drive - RAID is a *technology* not an action, just as USB is a technology therefore 'RAID is not a backup' in the same way that 'USB is not a backup'
RAID is a *technology* not an action, just as USB is a technology therefore 'RAID is not a backup' in the same way that 'USB is not a backup'
BINGO!
Here is my main issue with the many people who say "RAID is not a backup". If you present a solution to virtually anybody ("the masses", not necessarily the educated) where: 1) Your data is on your PC's hard drive 2) You copy (or is auto-copied) your critical data to a separate physical drive such as an external USB drive
... then "everybody" would agree that you "made a backup copy of your data". However -- this really only protects your data from a single drive failure. If the 2nd drive is on your PC, it is also subjected to whatever virus you may get that destroy's your first drive. If your house is destroyed by a meteor, tornado, fire or flood -- or a burglary removes all your high-tech stuff... then YOU STILL LOSE YOUR DATA.
So, though everybody considers a 2nd copy (same physical location) as "a backup" -- the ReadyNAS is *better* since it self-monitors and warns of anticipated failures. Why is the first "a backup" and not the ReadyNAS?
True, every bit is not specifically backed up -- but, the ESSENCE of every bit is. Every bit that is lost from a drive failure can be ACCURATELY recreated. This is what backup really means - the ability to recover the missing data when the original is lost.
Thus, my argument is: The only thing REALLY safer than ReadyNAS-stored data... is OFFSITE-stored data.
Personally, I trust the data on my ReadyNAS more than data I have on my PC and a copy on a USB drive plugged into it (especially considering user-account security!).
Given this, I wish people would alter their stance:
A ReadyNAS, like a 2nd hard drive, is not a secure backup solution.
(edit: Mea culpa; I did not intend this thread for "expansion" - I failed to pay attention last night; if a mod could move it to a more appropriate DISCUSSION thread, I would appreciate it!)
RAID-5 and RAID-1 provide redundancy. They each protect against a single hard drive failing, allowing high up time and minimising the likelihood of needing to restore data from backup. Disk failure is very common and is important to protect against.
The general consensus in the IT community is that RAID and backup are two different things. A backup stored on a separate device is different to RAID. Yes, if you accidentally delete something or corrupt it, it could be replicated to a backup when that takes place, but it's not immediate. RAID was never designed to be treated as providing a backup of data, because it's not. You delete a file and it's gone from your array immediately.
Having the primary copy of your data on the ReadyNAS and a backup on a USB drive, or the primary copy on a PC and the backup on a ReadyNAS are both better options than having the primary copy on a PC and the backup on a USB drive.
The main objection to people treating RAID as if it were backup, is to do with things like accidental deletion, file corruption (e.g. due to a failed memory module), and pulling a disk from a RAID-1 array, thinking that this will give them a backup of their data. By considering RAID and backup as two different things, the average user can learn the differences between the two and avoid making terrible mistakes.
Your argument fails when you you use terminology inconsistently & indiscriminately leading to straw man statements like this. "ReadyNAS" and "RAID" are not interchangeable terms
Your argument fails when you you use terminology inconsistently & indiscriminately leading to straw man statements like this. "ReadyNAS" and "RAID" are not interchangeable terms
No one made that claim in this thread, but I'll support it.
The statement was:
So, though everybody considers a 2nd copy (same physical location) as "a backup" -- the ReadyNAS is *better* since it self-monitors and warns of anticipated failures. Why is the first "a backup" and not the ReadyNAS?
Storing your data on ReadyNAS, or storing it on any single system with some type of RAID is not a "backup". The ReadyNAS and RAID will prevent you from having data loss in the event that a drive fails. What if: 1) files are deleted 2) files become corrupted 3) the raid controller breaks 4) a virus messes up your files 5) your device is stolen 6) readynas or your raid controller has a problem and wrecks your drives
In all of these situations, having an actual backup will save you. One of my clients didn't think they needed to worry much about backups because their server had RAID 5 and they'd get warnings if there was a hard drive problem. Then the raid controller failed. Guess what, now you have a bunch of disks that you can't read. There is your single point of failure. In reality it would have been the same thing if the server itself failed. There was no way to read those drives w/o the raid controller, just like you'll be SOL if your ReadyNas dies, until you can get a replacement ReadyNas and pray to god that it recognizes your drives correctly when you put them in.
