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 TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 89DEF158164 for ; Sun, 17 Nov 2024 11:22:53 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E6F39E0E61; Sun, 17 Nov 2024 11:22:46 +0000 (UTC) Received: from cross.elm.relay.mailchannels.net (cross.elm.relay.mailchannels.net [23.83.212.46]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 6D285E0DE5 for ; Sun, 17 Nov 2024 11:22:45 +0000 (UTC) X-Sender-Id: thundermail|x-authsender|confabulate@kintzios.com Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id B5DD22451D for ; Sun, 17 Nov 2024 11:22:43 +0000 (UTC) ARC-Seal: i=1; s=arc-2022; d=mailchannels.net; t=1731842562; a=rsa-sha256; cv=none; b=m8kZ/b5aHwpMDKrDThBOZGK3gKu1aKmHfw4GC59RM4Qau6r6/Z1OuVFPtW7Gzh8Tuz0skt 6k2SA8YV5reFJRJdDw8eqZYq0YcFXE184jn6iHQAti9xp0d83TxaXuLNIrnSx0IrQr4vEV HdGvBUsp4AJiYU7q/UfxSma0j5ZdjpwYZH9t6QGfWPN3YAZgsYaXipee6KrCpsBaPUcWKy AQ6oNz5jNygbN7bKlzfV97g7pY/45xJIs5CgORFO3jUtO+NhMU/VgOgeSvLAE1yXCuUoyg OASil1HEUeUR2vRINiUbPO35c0AZxgiWpSeUgsGfgExfkK1l2G3aewXl4Z7xFg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=mailchannels.net; s=arc-2022; t=1731842562; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=vIKKl4hKKpFRgNhtnNu8ReKl/BPVckm9oByXxdmCiXE=; b=F7AOBQuGG6zRvg8UHAoECVJ/kORnBVszbl1rz4u2dHwU+xZbyujAwHcYr9UjBm3/A7vjiy zKabvGCToQu815O1GJv0Zz/ayuGoSswhl7PZv1/OsJKC5E1dTHbDxgnMx/id7Go2BoXYF2 5qfBLuQyoWyLv6ZWEfHknys8OzGi5eDhJHkVkTxBoaYslZ98OFRLELkjLGUlbU7Oq1NCBD pEaRlvGk+gdAECZKssWmXl/DvB4AJzft8XMjiz7BpoVV4ajgrprN5xc06jKvDBCiCpbXoh 4MA+l5Q6RMq9XbJqV86OMqDl2Owo2laD4AKYkoSEp6vKPfzQ4R3tucE5u63oQQ== ARC-Authentication-Results: i=1; rspamd-645676964-f6mww; auth=pass smtp.auth=thundermail smtp.mailfrom=confabulate@kintzios.com X-Sender-Id: thundermail|x-authsender|confabulate@kintzios.com X-MC-Relay: Neutral X-MailChannels-SenderId: thundermail|x-authsender|confabulate@kintzios.com X-MailChannels-Auth-Id: thundermail X-Scare-Bubble: 6dd5f0394e4c16c4_1731842563173_2419191782 X-MC-Loop-Signature: 1731842563173:476608281 X-MC-Ingress-Time: 1731842563173 Received: from mailclean11.thundermail.uk (mailclean11.thundermail.uk [149.255.60.66]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.107.236.27 (trex/7.0.2); Sun, 17 Nov 2024 11:22:43 +0000 Received: from cloud238.thundercloud.uk (cloud238.thundercloud.uk [149.255.62.116]) by mailclean11.thundermail.uk (Postfix) with ESMTPS id C55A61E0003 for ; Sun, 17 Nov 2024 11:22:40 +0000 (GMT) Authentication-Results: cloud238.thundercloud.uk; spf=pass (sender IP is 217.169.3.230) smtp.mailfrom=confabulate@kintzios.com smtp.helo=rogueboard.localnet Received-SPF: pass (cloud238.thundercloud.uk: connection is authenticated) From: Michael To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Seagate hard drives with dual actuators. Date: Sun, 17 Nov 2024 11:22:15 +0000 Message-ID: <3598598.iIbC2pHGDl@rogueboard> In-Reply-To: References: <1836185.3VsfAaAtOV@rogueboard> 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; boundary="nextPart9366875.CDJkKcVGEf"; micalg="pgp-sha256"; protocol="application/pgp-signature" X-PPP-Message-ID: <173184255958.124804.5578586454090862379@cloud238.thundercloud.uk> X-PPP-Vhost: kintzios.com X-Spamd-Result: default: False [-1.51 / 999.00]; SIGNED_PGP(-2.00)[]; MID_RHS_NOT_FQDN(0.50)[]; ONCE_RECEIVED(0.20)[]; MIME_GOOD(-0.20)[multipart/signed,text/plain]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_TLS_ALL(0.00)[]; DMARC_POLICY_ALLOW(0.00)[kintzios.com,none]; FROM_HAS_DN(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; REPLYTO_DOM_NEQ_TO_DOM(0.00)[]; ARC_NA(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; MISSING_XM_UA(0.00)[]; ASN(0.00)[asn:34931, ipnet:149.255.60.0/22, country:GB]; MIME_TRACE(0.00)[0:+,1:+,2:~]; TO_DN_NONE(0.00)[]; REPLYTO_ADDR_EQ_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; RCVD_COUNT_ONE(0.00)[1]; PREVIOUSLY_DELIVERED(0.00)[gentoo-user@lists.gentoo.org]; R_DKIM_NA(0.00)[]; NEURAL_HAM(-0.00)[-0.999]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_SPF_ALLOW(0.00)[+mx]; HAS_REPLYTO(0.00)[confabulate@kintzios.com] X-Rspamd-Queue-Id: C55A61E0003 X-Rspamd-Action: no action X-Rspamd-Server: mailclean11 X-Archives-Salt: 036dadb2-45da-469d-9be8-b8bc7323c30a X-Archives-Hash: b6c179d1bd7c0629454126747435a3ba --nextPart9366875.CDJkKcVGEf Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Michael To: gentoo-user@lists.gentoo.org Reply-To: confabulate@kintzios.com Subject: Re: [gentoo-user] Seagate hard drives with dual actuators. Date: Sun, 17 Nov 2024 11:22:15 +0000 Message-ID: <3598598.iIbC2pHGDl@rogueboard> MIME-Version: 1.0 On Saturday 16 November 2024 20:13:30 GMT Rich Freeman wrote: > On Sat, Nov 16, 2024 at 2:47=E2=80=AFPM Michael wrote: > > What differs with > > HM-SMR instructions is the host is meant to take over the management of > > random writes and submit these as sequential whole band streams to the > > drive to be committed without a read-modify-write penalty. I suppose f= or > > the host to have to read the whole band first from the drive, modify it > > and then submit it to the drive to write it as a whole band will be > > faster than letting the drive manage this operation internally and > > getting its internal cache full. >=20 > I doubt this would be any faster with a host-managed drive. The same > pattern of writes is going to incur the same penalties. >=20 > The idea of a host-managed drive is to avoid the random writes in the > first place, and the need to do the random reads. For this to work > the host has to know where the boundaries of the various regions are > and where it is safe to begin writes in each region. The random reads do not incur a time penalty, it is the R-M-W ops that cost= =20 time. The host don't need to know where bands start and finish, only needs= to=20 submit data in whole sequential streams, so they can be written directly to= =20 the disk as in a CMR. As long as data and metadata are submitted and writt= en=20 directly, the SMR would be alike a CMR in terms of its performance. > Sure, a host could just use software to make the host-managed drive > behave the same as a drive-managed drive, but there isn't much benefit > there. You'd want to use a log-based storage system/etc to just avoid > the random writes entirely. You might not even want to use a POSIX > filesystem on it. >=20 > > This > > will not absolve the drive firmware from having to manage its own trim > > operations and the impact metadata changes could have on the drive, but > > some timing optimisation is perhaps reasonable. >=20 > Why would a host-managed SMR drive have ANY trim operations? What > does trimming even mean on a host-managed drive? >=20 > Trimming is the act of telling the drive that it is safe to delete a > block without preserving it. A host-managed drive shouldn't need to > be concerned with preserving any data during a write operation. If it > is told to write something, it will just overwrite the data in the > subsequent overlapping cylinders. I assumed, may be wrongly, there is still an STL function performed by the= =20 controller on HM-SMRs, to de-allocate deleted data bands whenever files are= =20 deleted, perform secure data deletions via its firmware, etc. However, I c= an=20 see if this is managed at the fs journal layer the drive controller could b= e=20 dumb in this respect. Perhaps what I had read referred to HM-SMR 'aware'=20 drives, which may behave as DM-SMRs depending on the OS capability. It would be interesting to see how different fs types perform on DM-SMRs. = =20 Looking at used drives on ebay they are rather still rather pricey for me t= o=20 splash out on one of them, but since my PVR 14 year old WD SATA 2 refuses t= o=20 die they may get cheaper by the time I need a replacement. --nextPart9366875.CDJkKcVGEf Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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