Using BTRFS for my main array. Convince me otherwise...

[unraidun]

So I've spent a lot of time researching the differences between XFS/BTRFS. All of the 'issues'/instability with BTRFS seem to be from years ago, mostly relating to RAID (which isn't a factor for us, right?).

 

There have been a handful of threads here on the forums, but I would expect more discussion when it comes to such an important (irreversible) decision..

 

The big selling point for me is data validation. Being able to periodically run 'btrfs scrub' just to verify the health of the disks (and system/memory overall) is a huge selling point. The peace of mind you get from that can't be under valued.

 

I was hoping XFS had something similar, and there does seem to be a new 'xfs scrub' command, but does that actually work like BTRFS? Are there even checksums to verify? Or is there some BETTER way to detect if a drive is silently failing/corrupting data with XFS?

 

Bottom line, if you're going to use UnRaid for a large file/media server (seems to be the most common use case), the only two major concerns I have are... 1.) How much wasted space does BTRFS generate (meta data etc...), and 2.) How much slower is BTRFS when reading/writing files. In the context of a file/media server, I have a feeling the answer to both of those questions is : an insignificant amount.

 

Assuming that is all true, can anyone convince me to use XFS instead?

 

Thanks

 

*and just out of curiosity, what is the logic behind forcing us to use BTRFS for the cache drive?

[JonathanM]

6 hours ago, unraidun said:

what is the logic behind forcing us to use BTRFS for the cache drive?

You certainly can use XFS for a single member cache. It's only when you have multiple cache device slots defined that you are forced to use BTRFS, because at the moment XFS doesn't support RAID volumes.

 

The major downside to BTRFS is that it seems to be more brittle or fragile than XFS. What I mean by that is a lack of tolerance for hardware or software errors, and the recovery options for broken BTRFS volumes aren't as robust as the tools available for XFS, so having a comprehensive backup strategy is, as always, a high priority.

 

So, if you are running server grade hardware with robust power conditioning, BTRFS has more options and features than XFS.

[PeteAsking]

I use btrfs on all my drives. Been using it as my daily file system on all my computers also for years. It used to have issues (like disk space disappearing) when I first started with it but since linux kernel 5 onwards pretty much everything has been sorted out in daily use. I dunno why the Ubuntu community hates it. They think its not being developed or something but its just slow work filesystem development. 

[unraidun]

Does anyone have experience with the new xfs scrub command? Or some other way to preemptively check the health of a file/disk? That seems to be one of the biggest differences between the two file systems.

 

Or perhaps there is some other xfs or btrfs feature I am overlooking?

 

But as I do more research on btrfs, it does seem like most of the bells and whistles it provides are useless for a simple 'write once read many media archive file server'...

 

 

Edited January 25, 2020 by unraidun

[methanoid]

Sorry havent been running unRAID for more than a year but I wasnt aware you COULD use BTRFS for your main unRAID array? I'd love to be able to have compression on my array by default...

[JorgeB]

9 hours ago, methanoid said:

but I wasnt aware you COULD use BTRFS for your main unRAID array?

You can, and starting with v6.12 you can also use zfs.