I have a raidz1. I want to know the level of redundancy I have.
I have a backup of about 10 TB but my NAS is 3 x 14TB so once I start filling it up I only have partial backup. 28 for data 14 for parity but if I only get some protection am I better off with no parity but a full backup?
With no protection, you are relying on a single backup I am guessing, which also means no protection unless that machine has redundancy. Many things can go wrong with backups, look up 3-2-1 backup strategy.
Raidz2 of course allows 2 drives to fail, z3 3.
My answer - if you value your data you are never better with no redundancy.
A backup gives you 2 sets of data. The original and the backup. The chance of loosing both at the same time is very low. And yes things happen like a fire but if that happens you’ll likely lose all anyway unless you have offsite backup. But how many can go to that level. I cant upload 28 TB to online storage, updating every time I make a change.
How many of us have unlimited funds to throw at redundancy/backup. I don’t. I just spent £600 on 3 drives for the NAS I don’t have more to throw at it.
Doesn’t change my answer, if you value your data… Fire, lightning (happened to me this summer), theft, and so on can lose your backup copy. And you are presuming the backup copy is good. If it’s not on a zfs filesystem or tested regularly, not good. It can also get corrupted. Perhaps less likely both would die, but, only with good hardware and regular testing.
Many people here have multiple backup types on multiple systems, it need not be expensive. In my case, I greatly reduced the expense by analyzing my data and categorizing the importance of each type by app. That made offsite backup feasible, and I have 2 of those. It made backup to external USB drive feasible, and it made Kopia feasible. Total offsite cost for me? $9/month
My nightly updates take around 2 minutes for Kopia to upload changes parts of files, and, around an hour for zfs replication.
I have set up a daily snapshot. Does it work similar to timeshift on Linux?
I use an older system that used to be my main FreeNAS and placed it at my company’s office. VPN connection from home to there - cheapest way to get offsite backup I can imagine for me.
Updating your backup should of course use a method that works incrementally so you do not need to “update 28 TB every time”.
If this is in any way business related - small company, self-employed, whatever as long as there is some budget - you can rent really large storage servers at reasonable prices from Hetzner. Install Debian, Ubuntu or FreeBSD, create a zpool - this can be used as a replication target by TrueNAS.
How much data are you backing up for $9 a month?
No, its home use but I have a lot of media that I would like to not lose. I’m just looking for the most cost effective way to do give me protection.
I’ve now got 1 drive for parity and 10TB backed up. That will give me a way to protect the media I don’t want to lose.
All the data I have analyzed and determined is not replaceable. I have about 8TB space on the external VPS, not sure how much I am using but it is ever expanding (my $9/month storage I am allowed to use grows every day). I gain something like 1 or 2 TB/year for $0.
Yes, to add onto pmh post, I have seen several here putting or using a machine at a friends or parents house. And vice versa, an arrangement where you use their system and they use yours for backups. Where there is a will there is a way often.
I was surprised what percent of my data was irreplaceable vs somewhat not wanting to lose vs who cares if I lose. More than half my data was who cares as apps have workspace, temporary space, etc. and once you analyze it, it became quite surprising to me.
Yep. A coworker’s home NAS also replicates to that same machine located at $office.
I don’t have anyone to do that with.
Then I wouldn’t use the NAS would be the way I would do it, I’d do something else. No one is making you do a backup, just a suggestion, seen so many people here lose irreplaceable data. For me, and I may well be extreme, my NAS is useless without backups (esp offsite multiple copies using different methods for the most critical data), I’d have never gone down that road as I absolutely positively cannot lose certain data. I feel the same about a UPS for the NAS also.
I’m not saying have no protection. I’m trying to work out why redundancy/parity is better than a backup or is it and what am I protected against? That’s all.
At the mo I have z1 with snapshots turned on and 10 TB backup. That 10 TB covers the most important stuff I don’t want to lose. I can always add another external drive if I have to, but where does it end lol.
I understand. To answer your original question…
If the ONLY 2 choices somehow were no parity and a backup, or, parity and no backup, I would choose no parity and a backup (well I wouldn’t but that’s me, I want 100% certainty I will not lose certain data!). Too many things can go wrong without a backup external to the system itself. Even ransomware. And yes, I don’t have 100% certainty, probably 99.99%.
And yes, snapshots that are not moved off the system does at least allow you to have versions of files.
Yep, backups are a pain, I agree.
One way to think of it: Redundancy (like in a mirror or RaidZx) is about avoiding long downtimes while backups is to avoid losing data. Without redundancy, a failed drive can still be restored from backup instead of parity. It will only take longer to get your system back online again.
That’s a good concise way of explaining it.
