From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 58FD313933E for ; Wed, 30 Jun 2021 23:32:07 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 40892E0844; Wed, 30 Jun 2021 23:32:00 +0000 (UTC) Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id D1286E0837 for ; Wed, 30 Jun 2021 23:31:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1625095907; bh=CaLEvkHLl1ZOeuPh12E7I9V1hLf07j0Uxr5MVYQh6u0=; h=X-UI-Sender-Class:Date:From:To:Subject:References:In-Reply-To; b=GGTvyHtFKUbmzLhacQw6eTL++dVn4o+Rs4MIZOYjgTQsysUZyJXLz7E9FTXuyAnbk +mY41XlDRitD21w9IJyDRS8nOKnmN4DSoTp6Ppnz4RrQPX/DjOghUPc+7OFTViO8xX 87Kq6ZdHidXloLdvE5T+LbLPIr7erE0/KTNncDHw= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from kern ([92.117.33.81]) by mail.gmx.net (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MyKDU-1l00EA3hgS-00yhRR for ; Thu, 01 Jul 2021 01:31:46 +0200 Date: Thu, 1 Jul 2021 01:31:44 +0200 From: Frank Steinmetzger To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] [OT] Using an odd number of drives in ZFS RaidZ Message-ID: Mail-Followup-To: gentoo-user@lists.gentoo.org References: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="bliMh2h+AgVzjF1z" Content-Disposition: inline In-Reply-To: User-Agent: Mutt 2.1; VIM - Vi IMproved 8.2 X-Provags-ID: V03:K1:9Ubr1lx+EjgUAvn3fGY2d/bAXMYfm19Ga7OV/i4BHQAS3F6VX8m 9OjMQMR01TbVnoh8/r7xg+qJ88RMhtGWJaSwA8ajS0jE/zqoQP4WgtCwh+f9nS36NUvHerB lt7gieAdqhXY7lfq6HnHAkWYj4F5y4k622/gXh0Qkk5B64HkjBnUwuzB5zxSka2CKwGidsn qiUftgTTVUqpMJbiB+gmw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:2B+z91PAAVQ=:rA9oDcfilri6EsEzJeDLfm TLNUlSnNT8vcDphaRT173d5tqswRNt9UogQUOqwuGp1cbNEmLekYeb1dr71h6xwiRmPSYl+EO StIFSVXHQfzQntH4Sy5WEdGuDIJ8syvMVDt+NsbUWHpFtSHBIAlSZc44N6q/Bt6+17O55GMUv BfRgypFaZ6K8aDywYP5ummW4mgJcSwfLgV1gMCmWidH4uS6UXkYOBs2cssezbBmBldsaIgh10 SSnGzBSKMnKwrfrryQpo3B3OTfz30vhPniQoTKNUM5Ah3Cm2u/M2vxHCchbv86cjHwXvGumcX D3VLQUR+ny5vpttgaD/f2LTkKuFhhFS4KXx7X3GESX7ZqLaVV1pwhKCIod/7ekGrRDm2iOGXZ hcNv/QiZF2WTRrAhPJ785oXbMjj71WopIWCtL8UuHi47ga/wVLVd6Kw8uEy42gTR0SdtDFm0R 2hHjwkD6YZfzRzUTrQ7Ti9sDyQ6LuwHlLYCRzH/N67Wm1Twn0M5iM36mxtOyd8CJm/tUc9RI6 8/GlxFTXy4zT4T5Lh02Dp01ABidRyokdxn8SwgXMVcG/zxhscwOpj9uIFKY2TvE2kOZ5z5Iyy 2mKLFfMv5X9C8qaNnauvJEkHNPYa4cMm3tVxfJCrwFRyon1xyjiw3/DvB5wvjWQ97P6EMTsWt P0EZ1te5e+GeYetwUIYddsAlH4B+qV2rXXMY5OgPWErBXp/LS4Z+nNODn81v8Gokc33hk4yJU MfrSsl2TuxFhkgFOGtn8B0y2pZH0T56jwaUeBpBKeyra/h+hIUOe7Kfr/Oy27AYDLLlZuFcM1 faewgtvuPdbsfDOOCIUt/wsvZR0MXA9bWVzvzPwOWiOA6M6ey0r16oFkIVqN2qk83k/gGAGcs VjLgscEokLzNfRREYJyvfe+pt1qCb1PF4ToZ1uDICWjYQLKjBiuvlUajcmLOwXR8l6/3brblR EiaSjIWNONFtLHQT6vR0nc/48AriR/mcEs1AcIOO2i755so1w6ZmJebuTG0nhMZ99WJYeHsBM S4mHy7PULohKdFK8sR3ld2IM7dGWlJdo+mYvo5+rChCGlDG+ZN61PHXYb8iRKI9zOm5zIz9Jv nwYU6w+jPPo5PZi7gLFvk4jtFJGeeZTw3HU X-Archives-Salt: bb36f3d9-b9d3-4f66-82da-d8710ca7e8c7 X-Archives-Hash: d6facedb3b8abb664ebcb8d238197410 --bliMh2h+AgVzjF1z Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Am Wed, Jun 30, 2021 at 09:00:29PM +0100 schrieb antlists: > > I reached 80 % usage (which is the recommended maximum for ZFS) and am > > now evaluating my options for the coming years. > > 1) Reduce use of space by re-encoding. My payload is mainly movies, amo= ng > > which are 3 TB of DVDs which can be shrunk by at least =E2=85=94 by= re-encoding. > > =E2=86=92 this takes time and computing effort, but is a long-term = goal anyway. > > 2) Replace all drives with bigger ones. There are three counter argumen= ts: > > =E2=80=A2 1000 =E2=82=AC for four 10 TB drives (the biggest size av= ailable w/o helium) > > =E2=80=A2 they are only available with 7200 rpm (more power, noise = and heat) > > =E2=80=A2 I am left with four perfectly fine 6 TB drives > > 3) Go for 4+2 RaidZ2. This requires a bigger case (with new PSU due to > > different form factor) and a SATA expansion card b/c the Mobo only = has > > six connectors (I need at least one more for the system drive), cos= ting > > 250 =E2=82=AC plus drives. > > 4) Convert to RaidZ1. Gain space of one drive at the cost of resilience= =2E I > > can live with the latter; the server only runs occasionally and not= for > > very long at a time. *** This option brings me to my question above, > > because it is easy to achieve and costs no =E2=82=AC=E2=82=AC=E2=82= =AC. > > > 5) Dunno if this is possible but ... replace one 6TB by a 12TB (any reason > you don't like Helium?) It is technically impossible to keep it in. It will diffuse through the case eventually, because the atoms are smaller than in any other material. AFAIK, the drive will still work, but suffer reduced performance. But I=E2=80=99m = not sure. And who knows how it will behave in a RAID once that happens. Big capacity drives need longer to rebuild, which increases the probability of failure during RAID rebuild. I think that=E2=80=99s why companies tend to stick to = smaller drivers (2 TB or so). I also prefer slow spinning disks (power consumption and noise). There is exactly one HDD model with 10 TB, no helium and 5400 rpm (naturally non-SMR). It=E2=80=99s a =E2=80=9CWD Red Desktop Mainstream Kit=E2=80=9D, w= hich in itself sounds like an oxymoron. > and raid-0 two of the remaining 6's together. Dunno anything about what > the raidZ's are but I presume this would give you 12TB of mirrored > storage. It would also only use 3 slots, The approach in itself sounds interesting =E2=80=93 if I already had the dr= ives. But I don=E2=80=99t, and so I=E2=80=99d have to pay 350 =E2=82=AC to get 2 TB m= ore effective storage, while still losing one level of redundancy. :-/ > so you could use the 4th for eg your videos, and back them up on external > storage ie the drive you've just removed :-) Unfortunately, I can come up with many reasons against this approach. - I don=E2=80=99t like the idea of using two different file systems for one= single purpose, because sooner or later one will fill up and the data =E2=80=9Cs= pills over=E2=80=9D to the other FS. Just the idea that this might happen bugs = me and I=E2=80=99d always have to think of it when I copy something over, starti= ng with the decision on which FS to use in the first place. ;-) - I don=E2=80=99t want to have to deal with making backups to external medi= a. I=E2=80=99d have to hook them up regularly and maintain and run a backup tool. - I don=E2=80=99t want to rely on external storage in general. That=E2=80= =99s what I bought the NAS. :o) I used external drives exclusively until I had the NAS. Over time, the biggest drive of the day became too small and I bought a bigger one as my wallet allowed (sounds like the story Dale told some time ago). The first had 500 G, then 1 T, then 3 T. Each one has its own power adapter, usually incompatible with anything else I have. It needs a reliable USB connection, yadda yadda. The files will inevitably become cluttered and dispersed and I need to keep tabs on what was where. No thanks. :) I do have a hot swap bay in my PC for bare drives=C2=B9. But SATA connectors aren=E2=80=99t made for many physical connect-disconnect cycles. =C2=B9 https://en.sharkoon.com/product//12640 > (The raid-0, I'd probably stripe rather than linear for performance.) When I did some research over the last days I read that ZFS distributes writes across all vdevs of a pool depending on their individual fill state. So one doesn=E2=80=99t really have control over linear vs. striped anyway. Dang, I wanted to go to bed 1=C2=BD hours ago. Instead I composed mails. :) --=20 Gr=C3=BC=C3=9Fe | Greetings | Qapla=E2=80=99 Please do not share anything from, with or about me on any social network. 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