Solved What BYO multi-terabyte storage solution do you recommend

hdmi · Nov 15, 2023

Dru2 said:
, so technically your data is backed up in that should one drive die, the data is still on the other drive.

Technically (and non-technically) your data is not backed up, as a mirror is not a backup in any way, shape or form. I have already previously tried to explain why... it's because, by mere definition alone, a backup of a dataset that is stored on the primary information repository requires (!) to be stored on a secondary information repository that is (also by mere definition alone) separate from the primary one, and, in RAID, two members of the same RAID array can never be in two different information repositories at once. For this, at least one of both physical drives (each one of which is a member of the same RAID array) would have to be physically removed from the RAID array. So, specifically in this regard, RAID is merely equivalent to JBOD, as the "elsewhere" in "storing a copy of the data elsewhere" is not referring to "elsewhere within the same information repository".

In addition to the above, the two members of the same RAID array always ramain in the same information repository until at least one of both members is physically removed not just from the RAID array itself, but from the whole system that provides data access to this same information repository via (a) data connection(s). One example of a system that provides data access to a secondary information repository is a backup server.

Further, in a typical home network environment where the average user (who only has a basic skillset and knowledge) is running a NAS, the NAS neither is a secondary information repository nor can be considered a part thereof. That's just because in such an environment the connection method or infrastructure used to hook up the NAS is typically not technically materially capable to divide the primary information repository into one primary and one secondary information repository. Rather, it's just a primary information repository that spans multiple enclosures and that's it... full end of story.

To summarize, the word "adequate" doesn't actually even begin to apply. Those who keep saying that they only plug in their NAS each time when they run their next backup job typically are those who are simply forgetting the fact that their secondary information repository immediately ceases to exist the moment when they plug it back in. Each time when they do that, it effectively becomes part of their primary information repository (i.e., an expansion thereof) until the next time when they unplug it. Again, whether their NAS uses RAID or JBOD, doesn't make a single difference in that regard.

Finally, RAID 1 (mirroring) reduces fault tolerance, the main purpose of which is to minimize the downtime (another benefit being that data can be read simultaneously from multiple physical drives so the read performance goes up... albeit JBOD does not prevent one from reading data from multiple physical drives per se...). That is, if only one drive fails in a RAID 1 array that consists of two physical drives, the system still continues to function normally. Whereas if the RAID 1 array consists of three physical drives, two drives can fail at once (or only one drive can fail and, next, before the RAID has successfully been rebuilt, a second drive can fail) and so forth. Hot standby, or hot spares can optionally be used (if the hardware allows it) so that the RAID rebuild can be started automatically as opposed to can be started only after the manual intervention of replacing failed drive(s), and, adding more members to the RAID 1 array can be considered (optionally also) to further strengthen resilience against multiple drive failures. (There also exist other forms of data mirroring besides RAID 1, though.)

As an aside, similarly, if the system uses two hardware RAID controllers (or HBAs) instead of only one, which is only one (common) example of what is known as duplexing, then if only one hardware RAID controller (or HBA) fails, the system still continues to function normally also.

pparks1 · Nov 15, 2023

Raid is not a backup, RAID 1 is not a backup. A backup means a secondary copy of your data you can pull if you corrupt your first one. If you get ransomware on your raid 1 drive and a file is encrypted and you are locked out of it, it's on both drive 0 and drive 1...exactly the same...locked out of both. Your "backup" copy on the 2nd drive does you no good whasoever here. But if you happen to have a drive fail, rest assured that that your ransomware encrypted file is still ransomwhere encrypted on the second drive in your RAID 1 volume.

Dru2 · Nov 16, 2023

Because people will argue if you say the sky is blue. We KNOW RAID IS NOT A BACKUP!!!!!

What I said, is certain RAID setups where you have multiple drives data will be mirrored to the other drive. Mirroring is a form of backup in that if one drive in a "RAID" setup goes, the data is on the other drive is there. Is this not true???

If someone said black was black, someone would tell you you're wrong, it's a shade of gray. If you said it was gray, they'd argue black.

Gesh.

hdmi · Nov 16, 2023

Dru2 said:
Mirroring is a form of backup

Still no.

pparks1 · Nov 16, 2023

Dru2 said:
What I said, is certain RAID setups where you have multiple drives data will be mirrored to the other drive. Mirroring is a form of backup in that if one drive in a "RAID" setup goes, the data is on the other drive is there. Is this not true???

If we want to argue the semantics of the word backup, one could go with your interpretation here and call it a backup. As a server engineer, we are taught and it's engrained in our brains that RAID does not remove the need for Backups.

I recall arguing with somebody here recently about the disadvantages of a RAID 1 mirror. Most would say, with RAID 1, or RAID 10, you lose 50% of your drive space. If you buy 2 x 8TB drives and configure them in a RAID 1 mirror, you get a total usable space of 8TB for storing files, folders, etc. This person argued that you didn't lose any drive space at all, you just used it in a different manner and it was storing the 2nd copy of each of your files....so he thought the argument that you only get 1/2 your drive space is garbage. That's obviously one way to interpret it.

I've found with both of these arguments here, it's probably just not worth arguing about them. RAID should not be considered sufficient and therefore eliminate a need to take backups. At work if I said, hey we got RAID we don't need backups, I'd get fired.

Baeolophus · Nov 16, 2023

Just to provide some practical experience to the discussion this thread has evolved into: 95% of the time I have had to resort to a backup was either the restore of an accidentally deleted file or directory, or the restore of a whole system after a clean install of the OS. In the one case I can think of, where I would have needed to retrieve a backup to restore a catastrophically failed system, that backup failed. At the time CrashPlan had incredibly cheap cloud storage, but somehow the restore failed because of some backup corruption issue. Needless to say, I am not with CrashPlan, anymore.

kelper · Nov 16, 2023

If you do occasional backups onto a RAID, it is backup. What puzzles me is people who want a live backup and don't realise that if they accidentally delete a file or folder it will also be deleted on their live backup. My backups are snapshots and can't be ruined by a stupid mistake on my live systems.

Marie SWE · Nov 16, 2023

Baeolophus said:
Just to provide some practical experience to the discussion this thread has evolved into: 95% of the time I have had to resort to a backup was either the restore of an accidentally deleted file or directory, or the restore of a whole system after a clean install of the OS. In the one case I can think of, where I would have needed to retrieve a backup to restore a catastrophically failed system, that backup failed. At the time CrashPlan had incredibly cheap cloud storage, but somehow the restore failed because of some backup corruption issue. Needless to say, I am not with CrashPlan, anymore.

*smiling* .. this is a classic forums phenomenon

The thing is as soon someone talks about raid and you use the word backup in the same thread even its different posts.. it almost always starts a debate

it doesn't matter if its a Windows forum or a Linux forum.. there is a few keywords in IT that always get the avalanche in motion.

So just grab your coffee, lean back and enjoy the ride. *LOL*

So if you are really bored some time.... combine words like you seen here.. Raid is backup... or VPN is privacy.. and what more is a good avalanche starters.. If you are on a Linux forum, I need an AV and a Firewall.. and on a windows forum.. Windows has builtin spyware and NSA backdors.. and so on..... Then you will be busy for the next few days. :wink:

johnlgalt · Nov 16, 2023

Or people could actually be decent human beings and stop arguing the same points over and over and over again....

Marie SWE · Nov 16, 2023

johnlgalt said:
Or people could actually be decent human beings and stop arguing the same points over and over and over again....

But do you really believe.. that will ever happen on open forums. *LOL* :wink:

It is good to mention it as a foot-note, as some dont know the difference.. but it don't need a five page debate though.

johnlgalt · Nov 16, 2023

If I believed it would actually happen, I'd probably not be so frustrated that it is not happening lol.

Marie SWE · Nov 16, 2023

johnlgalt said:
If I believed it would actually happen, I'd probably not be so frustrated that it is not happening lol.

True.. so true

But if its bad weather outside, a boring day with just crap on TV and nothing fun going on.. Then threads like this can be a bit entertaining to make time fly, :lmao: