Gentoo Archives: gentoo-user

From: Frank Steinmetzger <Warp_7@×××.de>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] OT: btrfs raid 5/6
Date: Thu, 07 Dec 2017 09:29:18
Message-Id: 20171207092856.GA29899@steinmetzger.isa-ilmenau.de
In Reply to: Re: [gentoo-user] OT: btrfs raid 5/6 by Richard Bradfield
On Thu, Dec 07, 2017 at 07:54:41AM +0000, Richard Bradfield wrote:
> On Wed, Dec 06, 2017 at 06:35:10PM -0500, Rich Freeman wrote: > >On Wed, Dec 6, 2017 at 6:28 PM, Frank Steinmetzger <Warp_7@×××.de> wrote: > >> > >>I don’t really care about performance. It’s a simple media archive powered > >>by the cheapest Haswell Celeron I could get (with 16 Gigs of ECC RAM though > >>^^). Sorry if I more or less stole the thread, but this is almost the same > >>topic. I could use a nudge in either direction. My workplace’s storage > >>comprises many 2× mirrors, but I am not a company and I am capped at four > >>bays. > >> > >>So, Do you have any input for me before I fetch the dice? > >> > > > >IMO the cost savings for parity RAID trumps everything unless money > >just isn't a factor. > > > >Now, with ZFS it is frustrating because arrays are relatively > >inflexible when it comes to expansion, though that applies to all > >types of arrays. That is one major advantage of btrfs (and mdadm) over > >zfs. I hear they're working on that, but in general there are a lot > >of things in zfs that are more static compared to btrfs. > > > >-- > >Rich > > > > When planning for ZFS pools, at least for home use, it's worth thinking > about your usage pattern, and if you'll need to expand the pool before > the lifetime of the drives rolls around.
When I set the NAS up, I migrated everything from my existing individual external harddrives onto it (the biggest of which was 3 TB). So the main data slurping is over. Going from 6 to 12 TB should be enough™ for a loooong time unless I start buying TV series on DVD for which I don't have physical space.
> I incorporated ZFS' expansion inflexibility into my planned > maintenance/servicing budget.
What was the conclusion? That having no more free slots meant that you can just as well use the inflexible Raidz, otherwise would have gone with Mirror?
> I expect I'll do the same thing late next year, I wonder if 4TB will be > the sweet spot, or if I might be able to get something larger.
Me thinks 4 TB was already the sweet spot when I bought my drives a year back (regarding ¤/GiB). Just checked: 6 TB is the cheapest now according to a pricing search engine. Well, the German version anyway[1]. The brits are a bit more picky[2]. [1] https://geizhals.de/?cat=hde7s&xf=10287_NAS~957_Western+Digital&sort=r [2] https://skinflint.co.uk/?cat=hde7s&xf=10287_NAS%7E957_Western+Digital&sort=r -- This message was written using only recycled electrons.

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Re: [gentoo-user] OT: btrfs raid 5/6 Richard Bradfield <bradfier@×××××.me>