How to evolve old storage system

pschatz100

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Mar 30, 2014
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1,184
You are way overthinking all of this.

You say you are concerned about the safety of your data. For your NAS, stay with NAS drives. WD Red, Seagate IronWolf, Hitachi Deskstar NAS are all good. Keep in mind, however, that 7200 rpm drives run a little hotter than 5400 rpm drives. I would stay with 5400 rpm drives. Definitely do not use WD purple drives - they are designed for a completely different purpose. It is not a matter of read/write speeds. For your stated purpose, disk performance is a non-issue.

You can replace your failing 3tb drive with a new 6tb or 8tb drive. Think about how much capacity you will need over the next 3-5 years, and choose accordingly. When you can, purchase a second drive and upgrade the mirror. That will solve your capacity problem on the 3tb mirror. Keep the good 3tb drive for later. Then, if you want to upgrade the 2tb mirror, you can use the 3tb drive from before, plus another new disk.

There is nothing inherently wrong with using two mirrors, although I think a 4 disk RaidZ2 is better because all your storage is in one pool and ANY two drives can fail before the pool is degraded. But, as you pointed out, you need all the disks up front in order to do that. I run a 4 disk RaidZ2 system at home, and I think it is a good balance between cost and data safety.

You have backups of your critical data, don't you? Mirrors and RaidZ2 are not a replacement for a proper backup strategy.
 

fierarul

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May 6, 2019
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> You have backups of your critical data, don't you? Mirrors and RaidZ2 are not a replacement for a proper backup strategy.

Actually, the NAS is starting to have the only copies of some old data. Considering I have snapshots for everything and there's a mirror why wouldn't this be a good backup strategy?
 

CraigD

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Mar 8, 2016
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343
Actually, the NAS is starting to have the only copies of some old data. Considering I have snapshots for everything and there's a mirror why wouldn't this be a good backup strategy?

You sever could be stolen or destroyed...

Use the 3 2 1 rule for important data

Have at least three independent copies of your data.
Store the copies on two different types of media.
Keep one backup copy offsite.

Have Fun
 

fierarul

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May 6, 2019
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I have actually been thinking about 3 2 1 too.

So, this means that FreeNAS is only 1 of the 3 copies? But what if I just want to archive stuff? Is a 2-drive or 3-drive or RAIDZ2 pool still "one" copy?

Do people really write their data on BluRay or some other non-HDD media? Seems quite impractical.

About the 'offsite' backup, I was talking a while back (on the old forum) that I could just take one disk from the pool and take it offsite.

Considering it's a mirror, all the data is there. And when I bring the old drive from the offsite location, FreeNAS would sync all the new data (or resilver). So... if I were to make a 4-drive mirror (silly?). I could have at any given point a 2-drive mirror which is redundant enough, 1 drive offsite and 1 drive en-route. The mirror will always be in a "degraded" state by having only 2 or 3 of the 4 drives.
 

Stevie_1der

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Feb 5, 2019
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So, this means that FreeNAS is only 1 of the 3 copies? But what if I just want to archive stuff? Is a 2-drive or 3-drive or RAIDZ2 pool still "one" copy?
Exactly.
If that server is physically destroyed or stolen, all data is gone, no matter how many copies of your files you had on it in different pools.

About the 'offsite' backup, I was talking a while back (on the old forum) that I could just take one disk from the pool and take it offsite.
Offsite backup can mean cloud storage or replication to a remote FreeNAS system (located at your parents' or a friend's house), if internet bandwidth is sufficient for that.
Or of course a separate HDD that is taken to an offsite location.
But HDDs are quite fragile, so if you drop it, it might be dead.

Do people really write their data on BluRay or some other non-HDD media? Seems quite impractical.
Well, dependent on the data amount of your really irreplaceable and valuable data this can be quite feasible.
Or for larger amounts, for example LTO tapes, but tape drives are rather expensive.
 

fierarul

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May 6, 2019
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I guess this makes me reconsider what FreeNAS is supposed to *be*.

I see some people really are using it as a NAS to store their ripped movies and such. Instead, I use it like a Time Machine for backups.

ZFS and a mirrored pool with snapshots seems like a good configuration to keep backups.

Doing 3 2 1 backups by the book doesn't really make sense. If you have everything stored online (say, in BackBlaze) then a simple external disk would suffice. Why care about ZFS redundancy when the data is also online? Only to prevent bit-rot?

So where is the value in using FreeNAS for backups in a 3 2 1 config? How are people doing this?
 

Stevie_1der

Explorer
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Feb 5, 2019
Messages
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Normally, people build FreeNAS (or other) systems as a primary central data storage (and that can be some quite powerful rig with loads of capacity).
And some people also have a local backup NAS and/or some offsite storage.

Other people use their NAS to additionally store their data from their devices in some centralized space.

If you only put ripped movies on your NAS, you already have 2 copies, the original discs, and the NAS storing the ripped content.
If your server dies, you can restore from the original discs, this is time consuming but possible.
If your house burns down, all 2 copies are lost.
But you even have kind of a third copy, you simply could buy the movies again (well, that would be a minor problem if your house just burnt down).
So in this case, you can ignore the 3-2-1 rule.

But when you store irreplaceable photos, home videos, business and/or private documents on your NAS, and you do not want to lose those under any circumstances, then you should use the 3-2-1 rule.

So the 3-2-1 rule only counts for irreplaceable and personally important data, and not so much for data that is reconstructible or reobtainable somehow.

In your case, when the NAS is only used for backups, then you already have 2 local copies (the original files on your PC, and the backup on your NAS), you'd just need an additional Backblaze copy and all should be safe.

Maybe this is a slight misunderstanding, but "3 copies" means the (identical) data is stored in 3 places like "my PC, my NAS, Cloud", "my PC, my NAS, HDD at my parents' house" or "my NAS, my backup NAS, cloud" etc.
It doesn't mean "the original file plus 3 additional copies".

Doing 3 2 1 backups by the book doesn't really make sense. If you have everything stored online (say, in BackBlaze) then a simple external disk would suffice. Why care about ZFS redundancy when the data is also online? Only to prevent bit-rot?
Of course it makes sense.
Imagine you have all of your data only on Backblaze.
What if the internet connection is down for some time?
What if some gigantic "oops" at Backblaze occurs and your data is gone?
If this was your only copy, you're out of luck.

ZFS with its redundancy and bitrot-countermeasures is used to keep the data alive and intact.
So you can continue working with that data even when a HDD fails, and don't have to import the backup.
If you just use a normal external HDD, it could be the data gets silently corrupted, and if you upload that to Backblaze, that data is corrupted, too
So you've lost all backups without even noticing.
If you have to recover from one of these backups, you'll notice it is useless and you lost that data.
 

CraigD

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Mar 8, 2016
Messages
343
I guess this makes me reconsider what FreeNAS is supposed to *be*.

I see some people really are using it as a NAS to store their ripped movies and such. Instead, I use it like a Time Machine for backups.

ZFS and a mirrored pool with snapshots seems like a good configuration to keep backups.

Doing 3 2 1 backups by the book doesn't really make sense. If you have everything stored online (say, in BackBlaze) then a simple external disk would suffice. Why care about ZFS redundancy when the data is also online? Only to prevent bit-rot?

So where is the value in using FreeNAS for backups in a 3 2 1 config? How are people doing this?

FreeNAS is a free operating for network attached storage, the name kind of gives away, and does its job very well

Bit-rot is one reason to use freeNAS, another is real time data availability in the event of a drive failure (sooner or later they will fail)

3 2 1 makes a lot of sense for you

Original data on your device that is backed up via Time Machine, a second copy on your NAS, the third copy off site on anything from a USB drive to a duplicate NAS, even cloud storage

Data security costs money, losing data can and does destroy people and businesses, most never recover

I've recovered the only copy of wedding photos from so called "professional photographers" failed external USB drive

Hope this helps
 

fierarul

Dabbler
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May 6, 2019
Messages
29
Thanks @Stevie_1der , this cleared some things for me.

I now see that the various RAIDZ1/RAIDZ2/mirror are all about risk/cost scenario. I could have a 3-disk mirror but then pay 3X for 1X of storage with the benefit of surviving 2 dead drives. Or I could have a RAIDZ1 with 2X of storage and surviving only 1 dead drive. Same with RAIDZ2...

For some data I do have a 2nd copy but I'm actually starting to clean up some old laptops and 'archive' data only to FreeNAS. This means I'm starting to have copies only on the ZFS mirror...

I have to think about moving a small server to some other location and sync with that... This is a lot of work.
 

fierarul

Dabbler
Joined
May 6, 2019
Messages
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I've recovered the only copy of wedding photos from so called "professional photographers" failed external USB drive

Heh, I have mixed feelings about photographers :) Our wedding photographer gave us the best photos in an animated flash EXE because he was afraid we would steal his pictures of our own wedding and forget to credit him or something. Quite annoying. Had to write my own little script that extracted the JPEGs from that EXE.

Data security costs money, losing data can and does destroy people and businesses, most never recover

Yes, I am buying more hard drives now after buying more ECC RAM :) Hopefully I'll figure out how to make the setup work. I still think that just yanking a bay from the microserver mirror pool and taking it offsite is a good strategy :D Cloud storage ain't cheap either.
 

fierarul

Dabbler
Joined
May 6, 2019
Messages
29
BTW, I learned something: replacing a drive with FreeNAS is done with the old drive in place! Which is correct! So with a 2-drive mirror you add the new drive, instruct ZFS to replace the drive and it does that while all 3 drives are online. Only after that you remove the faulty/old drive.

I the end I decided to *expand* my mirror to a 3-drive mirror and offline on drive from the other mirror pair (so one mirror is degraded now).

This post helped me add the 3rd drive to the mirror: https://www.ixsystems.com/community/threads/create-zfs-mirror-by-adding-a-drive.14880

I'm planning on growing this to a 4-drive mirror and rotating a drive for offline backup, like this post mentions https://serverfault.com/a/641217 This was my idea from the start and it seems it's been done before. Then I can claim to be close to 3-2-1.
 

Z300M

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Sep 9, 2011
Messages
882
SMR is here to stay, AFAICS. In another thread someone pointed out that some recent WD Reds are SMR, and I saw a brief YouTube video by an HGST (now part of WD) big wheel talking up their SMR drives. I skimmed through a Seagate YouTube presentation that sang the praises of SMR, but also (if I understood correctly) talked about the need for improved drive management.

AND I should not be surprised if -- to take examples from the Seagate range -- the difference between original "Archive" SMR drives, the Barracuda, the Barrcuda Pro, the IronWolf and the IronWolf Pro, is the presence or absence of internal electronics and solid-state memory and non-SMR areas that mitigate the problems seen with the original "Archive" drives (and I notice that the Exos range includes an ST8000AS003, which I assume is not that different from the original "Archive" ones).
 
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