Better to keep important data off Truenas if a newb?

[rufunky]

I've researched all the different most popular NAS options and decided to give Truenas a shot.

I now have it set up with the plex server plugin and it works well. Currently I only have a single disk system that I plan on adding a mirror to. I'm not really too concerned about the Plex media that is currently stored on there but was considering storing some more important files on there as well.

My question is, as a newbie, am I better off NOT storing more important files on my truenas as if something goes wrong it will be harder for me to recover my data. Or are snapshots just as good as any other means of recovering data provided said drive isnt completly dead..

 

[Etorix]

Data safety is the whole point of ZFS… BUT it must be done properly.

Currently I only have a single disk system that I plan on adding a mirror to.

Mirroring the boot drive is totally unnecessary in a home NAS. If that's not what you meant, please spend some time studying proper terminology so we can understand your questions and answer using a common language.

Terminology and Abbreviations Primer

We realize that new users have a lot to learn when they come to FreeNAS. There's a certain amount of confusion added to discussions when users pick random/approximate terms to describe things. I've spent a lot of time quietly trying to...

www.truenas.com

Data vdevs need to be properly redundant (2- or even 3-way mirrors, raidz2 or raidz3); snapshots are very useful to prevent accidents or malware (e.g. crypto lockers). Full security further requires backups to external systems or drives—as would be the case for any other drive and/or non-ZFS RAID system.

Or are snapshots just as good as any other means of recovering data provided said drive isnt completly dead..

If ZFS goes wrong there's not much in the way of "means of recovering data". So one needs to study and plan ahead for a setup which meets the requirements.

 

[rufunky]

Thanks so much for your response Etorix and the link to the Terminology and abbreviations primer!

Please forgive me, the OS is on a separate SSD... What I meant by a "single disk system" is a single disk for Data.

So I guess at this point if I add another disk for redundincy I would then create a "mirror vdev" for the Data vdev?

 

[Etorix]

Correct. Single disk vdevs are dangerous because there's no redundancy to correct errors. (Well, there's the option "copies=2", but it doesn't protect against hardware failure.) That may be fine for a jail/VM/container which can be recreated, but you should at least make a mirror before putting important data.

 

[rufunky]

Just to be sure, Is this the propper way of creating a mirror vdev? https://youtu.be/XBawO7btzuQ

 

[danb35]

I wouldn't agree with the "danger of disk failing" in any meaningful sense, but otherwise seems legit. There's also some relevant information in the second half of this post:

Newly replaced disk in 2 disk Mirror appears to have been Striped

Hmmm. I know the option is there in 12.0; perhaps it only shows up when your pool is mirrors rather than single disks. So in that case, you’re going to need to do it from the CLI. So let’s suppose I want to remove da2 from my pool. First, I need to find the gptid for da2: root@freenas[~]#...

forum.freenas-community.org

 

[artlessknave]

Mirroring the boot drive is totally unnecessary

if you have the drives and the connection space, there is also real no reason not to.
there is nothing wrong with single disk zfs pool, as long as you understand that, while it will detect data corruption, you will not get the self healing, since there is nothing to heal from. you will still get ARC acceleration, checksums, etc. in reality, a single disk zfs pool will likely still be more reliable than most other filesystems, since it will detect damaged files by design on any read, while others will return bad data cheerfully.

 

[Etorix]

@artlessknave Fair points… But since a single drive vdev can only be transformed into a mirror, and there's no straight way to change a mirror into a raidz#, or to upgrade a raidz1 into raidz2/3, it's better to plan secure data storage from the start.

 

[rufunky]

Thanks for all the replys, it really is appreciated.

Beisides the mirror vdev, backing up the config and doing snapshots is there anything else I should do as far as keeping the truenas system healthy?

 

[Arwen]

Schedule both scrubs & SMART tests. Make sure the E-Mail out function works. Their is a GUI menu for those configurations.

 

[rufunky]

Thank you Arwen. Is there a reccomended schedule for these tasks? Also, how often is reccomended for config and snapshops manual backups? IE once a day..

 

[Etorix]

Typically, short SMART tests would be daily and long test weekly to monthly. Snapshots are essentially free, so use as much as required… It is possible to have multiple snapshot tasks with different retention times, such as hourly, kept for a (few) day(s), daily for a (few) week(s), weekly for a (few) month(s), etc.

 

[rufunky]

Thank you Etorix. Got it, that makes sense :)

 

[artlessknave]

Snapshots are essentially free

while snapshots have no ultimate disk cost, you can reach a point where you have so many that it takes FOREVER to view them, and forever+days to delete one of them

it's better to plan secure data storage from the start.

you should always have a plan, but raidz doesnt have to be part of that plan. mirrors perform fastest in general, are simpler to plan for and manage (you can add AND remove disks within mirror vdevs), are simpler to resilver, and can require less drive replacements to expand your storage (if you have a 6 drive pool of 2 way mirrors, you can use 2 drives to replace one vdev with 14TB drives, and you will have the full 14TB. with raidz the entire vdev will be limited by the size of the smallest drive, period, so if you have a 6 drive raiz2 of 2TB, you need to have 6x14TB drives for it to actually expand)

 

[Etorix]

@artlessknave Fair points again, but here I'll beg to disagree and stand my ground. I takes an unreasonably large number of snapshots to run into performance issues. Mirrors may have merits even for simple storage (not just block storage), but even then they should be planned in advance, not chosen by default because the pool began with a single drive. And, for the same reason that raidz1 is now advised against, I would personally not trust data to a mere 2-way mirror of 14 TB drives—I'd want at least a 3-way mirror with such large drives to be reasonably confident of recovering from a drive loss without resorting to restoring from backup (which I have).

Hopefully, this will provide @rufunky some clues to make a choice which fits his own requirements (or his own degree of paranoia…).

 

[rufunky]

It definatly does help. Again, I appreciated everyone for takeing the time to educate me.

Looks like there is more than one way, with each having it's own positives and negitives.
I guess it all boils down to "How important is the data?"

A good majority of my data is replaceable. For the stuff that is not, I will most likely keep copys on my truenas as well as on seperate external drives formated in NTFS as this is what I am most comfortable with as far as recovering data.

 

[artlessknave]

I will most likely keep copys on my truenas as

if the non replaceable bits are relatively small, you could also make a cloud sync task for them to something like google drive, backblaze etc.

seperate external drives

I chose freenas originally, specifically to never have to do this. the only drives with data I care about are handled by zfs and TrueNAS. anything on laptops or desktops is transient stuff, like application installers, game installs, iso files, etc. I dont backup windows installs even; if it crashes, it's time for the clean install I have probably been putting off.

 

[artlessknave]

mere 2-way mirror

2-way mirrors, however, will usually resilver *dramatically* faster. raidz1 is not recommended because of the resilver time, but a mirror basically resilvers at the read speed of the existing drives and the write speed of the new drive, there is no parity calculation needed, it doesnt need to read 6 or 7 drives to resonstruct data from parity, etc.
3-way mirror in terms of reliability is closer to raidz3, and WAY overkill for basically anything. the chances of 2 drives failing in the same 2-way mirror vdev before at least one of them can be resilvered is not that different from 3 drives failing in a raidz2, and if you have backups, which you definitely should, even if the pool dies, its an inconvienience, not a loss.
when you read from a raidz2 vdev, all disks must respond, but when you read from a mirror vdev, only 1 disk must respond.

all things that need to be considered when making your plan. when I last rebuilt my bulk pool, i used raidz3 on 11 drives. if i rebuild it, I've been thinking of using 2 ways mirrors. I haven't had any drive fail in years. raidz2/3 looks like more space, on paper, but one problem you run into is that you have to upgrade every drive in the vdev before it can expand, which means the entire raidz2/3, while in mirrors you only have 2-3 drives in each vdev, and get more efficient usage when expanding drives. right now, any drive bigger than 4TB is a mostly wasted drive for me, cuz I still have 5 4TB drives.