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
1 On Thu, Dec 07, 2017 at 07:54:41AM +0000, Richard Bradfield wrote:
2 > On Wed, Dec 06, 2017 at 06:35:10PM -0500, Rich Freeman wrote:
3 > >On Wed, Dec 6, 2017 at 6:28 PM, Frank Steinmetzger <Warp_7@×××.de> wrote:
4 > >>
5 > >>I don’t really care about performance. It’s a simple media archive powered
6 > >>by the cheapest Haswell Celeron I could get (with 16 Gigs of ECC RAM though
7 > >>^^). Sorry if I more or less stole the thread, but this is almost the same
8 > >>topic. I could use a nudge in either direction. My workplace’s storage
9 > >>comprises many 2× mirrors, but I am not a company and I am capped at four
10 > >>bays.
11 > >>
12 > >>So, Do you have any input for me before I fetch the dice?
13 > >>
14 > >
15 > >IMO the cost savings for parity RAID trumps everything unless money
16 > >just isn't a factor.
17 > >
18 > >Now, with ZFS it is frustrating because arrays are relatively
19 > >inflexible when it comes to expansion, though that applies to all
20 > >types of arrays. That is one major advantage of btrfs (and mdadm) over
21 > >zfs. I hear they're working on that, but in general there are a lot
22 > >of things in zfs that are more static compared to btrfs.
23 > >
24 > >--
25 > >Rich
26 > >
27 >
28 > When planning for ZFS pools, at least for home use, it's worth thinking
29 > about your usage pattern, and if you'll need to expand the pool before
30 > the lifetime of the drives rolls around.
31
32 When I set the NAS up, I migrated everything from my existing individual
33 external harddrives onto it (the biggest of which was 3 TB). So the main
34 data slurping is over. Going from 6 to 12 TB should be enough™ for a loooong
35 time unless I start buying TV series on DVD for which I don't have physical
36 space.
37
38 > I incorporated ZFS' expansion inflexibility into my planned
39 > maintenance/servicing budget.
40
41 What was the conclusion? That having no more free slots meant that you can
42 just as well use the inflexible Raidz, otherwise would have gone with Mirror?
43
44 > I expect I'll do the same thing late next year, I wonder if 4TB will be
45 > the sweet spot, or if I might be able to get something larger.
46
47 Me thinks 4 TB was already the sweet spot when I bought my drives a year
48 back (regarding ¤/GiB). Just checked: 6 TB is the cheapest now according to
49 a pricing search engine. Well, the German version anyway[1]. The brits are a
50 bit more picky[2].
51
52 [1] https://geizhals.de/?cat=hde7s&xf=10287_NAS~957_Western+Digital&sort=r
53 [2] https://skinflint.co.uk/?cat=hde7s&xf=10287_NAS%7E957_Western+Digital&sort=r
54
55 --
56 This message was written using only recycled electrons.

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