Ashton Fagg wrote:
> Hi all,
>
> I'm currently in the process of provisioning a new NAS for home. It's
> replacing an older Synology unit that ticks me off in so many ways.
>
> I am looking to hear other's experiences with using OpenBSD as a NAS -
> specifically in terms of reliability, and for suggestions on how to
> provision my storage.
>
In my experience practical, answerable OpenBSD specific questions based
on actual problems that people face are more likely to get you an answer
on this mailing list than inviting subscribers to share their experience
and opinions. Here is my experience/opinion.
OpenBSD is super simple and most reliable OS I have personally dealt
with but the storage OS, it is not. Nevertheless some people are using
in that capacity and to paraphrase Nick's point if OpenBSD is your goto
OS, there is nothing wrong in storing and sharing a few files of OpenBSD
box instead of picking up and introducing another OS into your home
environment.
Building a home NAS involves solving the following five sub-problems.
1. The choice of volume manager (HWRaid vs SoftRaid vs ZFS).
2. The choice of file system (legacy vs modern (ZFS, HAMMER, HAMMER2).
3. How are you going to share the files (NFS, SMB, GlusterFS)
4. How are you going to back up your NAS server (tape, disk, remote
machine)
5. Inquiry, monitoring, and alerting of your NAS server for data
integrity and performance.
> I have an LSI card (supported by the drivers in OpenBSD) that is
> currently flashed to IT mode, but it can of course flashed back to the
> IR firmware which lets it act as a hardware RAID controller.
>
So we are now talking about the volume manager. I have not used HWRaid
on OpenBSD but I have used SoftRAID.
oko# bioctl softraid0
Volume Status Size Device
softraid0 0 Online 2000396018176 sd3 RAID1
0 Online 2000396018176 0:0.0 noencl <sd0a>
1 Online 2000396018176 0:1.0 noencl <sd1a>
At my place of employment I have used high end LSI HWRaid cards, I have
used Linux SoftRAID, and I am currently using ZFS (FreeBSD). I would not
recommend HWRaid cards to a home user. Between Linux SoftRAID and ZFS on
FreeBSD, ZFS wins hands down. That being said I neither have a need nor
a hardware good enough to use ZFS at home.
Comparing to Linux SoftRAID, OpenBSD is super crude. Once upon a time I
accidently off lined one of the HDDs in RAID1 mirror. It took probably 2
days to rebuild 2TB mirror. The things might have improved. Look for the
posts of Karel Gardas who IIRC was one of the guys fiddling with
SoftRAID after the original creator Marco Peereboom left the project
probably 10 years ago. If you have more than a 1-2 TB of data I would be
very worried about using OpenBSD softraid. The best thing is to test
before your commit.
>
> My needs for the NAS are as follows: NFS and Samba share support,
That is item 3 on my list. I have not run Samba server of OpenBSD box.
I have run NFSv3 server for educational purposes and I currently use
OpenBSD NFSv3 client. My needs are very limited so I am not sure if much
has changed since Matt Dillon of DragonFly BSD fame gave me a bit of
education
http://lists.dragonflybsd.org/pipermail/users/2016-April/228719.html
> reasonable performance, some amount of tolerance to disk failure,
> reliable and trustworthy software and file system, ability to closely
This is item 2 on my list. OpenBSD doesn't have a "modern" file system
but that is also true for most other actively developed OSs with
exception of FreeBSD and DragonFly BSD. Note that I don't consider
Illumos kernel and OmniOS in particular activelly developed systems. ZFS
on Linux is PITA and on the NetBSD doesn't look much better. If you need
copy-on-write, check-sums, consistency and such your choice is pretty
much among ZFS, Hammer, and Hammer2. If you stick with OpenBSD's FFS2
start by looking for Solene Rapenne's posts and his blog
https://dataswamp.org/~solene/2017-03-17-integrity.html
> monitor disk/array health. By extension, it should also be as simple as
> possible.
That is item 5 on my list.
In my experience bioctl is good enough for home users. YMMV. Start by
reading
https://www.openbsd.org/papers/opencon06-bio.pdf
I wish somebody could point me to anything more recent.
>
> It might be nice to have it be able to host an iSCSI volume, but that's
> not essential.
I am confused now. You said you are building NAS. Now you are talking
about SAN. I would suggest you familiarize yourself with this paper
before going further
https://www.open-e.com/site_media/download/documents/Open-E-white-paper-EN-web.pdf
>
> I don't care about bleeding edge performance, fancy web UIs or any other
> "shiny" stuff.
>
> By my estimates, OpenBSD with softraid volumes should tick all of those
> boxes. The box will do nothing else besides be a file server. OpenBSD is
> my preferred OS nowadays, but I am open to something else if it's the
> best tool for the job. I guess I'm trying to find out if there's any
> compelling reason why I *shouldn't* use OpenBSD with softraid.
>
> (ZFS also scares me, btw. Maybe unjustifiably so, but it seems very
> complex and I suspect much of the hype comes down to zealotry and
> fanboyism.)
>
> The questions I have are:
>
> a) Is softraid reliable enough to support my use-case? Does anyone have
> anecdotes to encourage/discourage use of softraid for this application?
>
> b) Would I be better off using the LSI RAID controller for the arrays?
>
> c) Bearing in mind that the provisioning scheme I have in mind is to
> provision the disks in pairs (forming RAID1 arrays), thus resulting in
> 3-4 separate volumes (6-8 disks), is there any reason I should *not* use
> OpenBSD, and look more toward something like TrueNAS or FreeBSD?
>
> (Before anyone mentions it - Yes, I have a proper backup system. I do
> not rely on the redundancy provided by RAID arrays in lieu of a real
> backup. I have both a local backup and offsite backup.)
>
> Thanks in advance.
