From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: from tb-ob21.topicbox.com (tb-ob21.topicbox.com [173.228.157.67]) by inbox.vuxu.org (Postfix) with ESMTP id 75BF72621F for ; Wed, 31 Jul 2024 04:07:41 +0200 (CEST) Received: from tb-mx1.topicbox.com (tb-mx1.nyi.icgroup.com [10.90.30.61]) by tb-ob21.topicbox.com (Postfix) with ESMTP id B41EF1FB20 for ; Tue, 30 Jul 2024 22:07:39 -0400 (EDT) (envelope-from bounce.mM193f031acea0a531d106af6c.r522be890-2105-11eb-b15e-8d699134e1fa@9fans.bounce.topicbox.com) Received: by tb-mx1.topicbox.com (Postfix, from userid 1132) id 5C3BE1E87B8F; Tue, 30 Jul 2024 22:07:39 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=9fans.net; h=from:to :subject:message-id:references:in-reply-to:date:mime-version :content-type:content-transfer-encoding:list-help:list-id :list-post:list-subscribe:reply-to:list-unsubscribe; s=dkim-1; t=1722391659; x=1722478059; bh=lIDA87xMMohrqfHFRJ7kSAAI4jHpAQ65 lhFq/7FDF80=; b=DNMZ2g1CquQ7n79aZ7/l9E5h/QlQGXgdfr2A9r69pMxXC6x8 pkTxXMSikZv/qmXll4dlm9IgvsT2atg+YdYTQrYA5Z2TrGgTj6FgDMYhzjgW4vYU 1H28nWt2TCf6hWWviiBMBtbGqUr4eM1LMLvRLXYGiS4P4FNUKctchzNHIvE= From: moody@posixcafe.org To: 9fans <9fans@9fans.net> Subject: Re: [9fans] Re: venti/mirrorarenas usage Message-Id: <17223916540.d9CdBad2.972286@composer.9fans.topicbox.com> References: <1833183.1722388779@LUNACY.UGRAD.CS.CMU.EDU> <17223896110.D36F.834362@composer.9fans.topicbox.com> In-Reply-To: <17223896110.D36F.834362@composer.9fans.topicbox.com> Date: Tue, 30 Jul 2024 22:07:34 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=17223916541.EE24.972286 Content-Transfer-Encoding: 7bit Topicbox-Policy-Reasoning: allow: sender is a member Topicbox-Message-UUID: a6c82388-4ee1-11ef-97e6-c256242d11b0 Archived-At: =?UTF-8?B?PGh0dHBzOi8vOWZhbnMudG9waWNib3guY29tL2dyb3Vwcy85?= =?UTF-8?B?ZmFucy9UY2EwZWIwZmJiMjQwNGUzMS1NMTkzZjAzMWFjZWEwYTUzMWQxMDZh?= =?UTF-8?B?ZjZjPg==?= List-Help: List-Id: "9fans" <9fans.9fans.net> List-Post: List-Software: Topicbox v0 List-Subscribe: Precedence: list Reply-To: 9fans <9fans@9fans.net> List-Unsubscribe: , Topicbox-Delivery-ID: 2:9fans:437d30aa-c441-11e9-8a57-d036212d11b0:522be890-2105-11eb-b15e-8d699134e1fa:M193f031acea0a531d106af6c:1:B9-66WiH3BlIzUUB-zYPSIJo0E_t-l_PprIqA4XULH4 --17223916541.EE24.972286 Date: Tue, 30 Jul 2024 22:07:34 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable If you look at the top of the file you'll see: /* * Mirror one arena partition onto another.=20=20 * Be careful to copy only new data. */ Now if you combine this with some of the information from venti(8): The data log is logically split into sections called arenas, typically sized for easy offline backup (e.g., 500MB). A data log may comprise many disks, each storing one or more arenas. Such disks are called arena partitions. Arena par- titions are filled in the order given in the configuration. My best guess is that this is an incremental backup tool, where you give it= a source and destination arena partition and the code looks at both, figur= es out the deltas, then copies over only what is needed. The venti code is = a bit inscrutable and I'm no venti guy so take this with a grain of salt. ------------------------------------------ 9fans: 9fans Permalink: https://9fans.topicbox.com/groups/9fans/Tca0eb0fbb2404e31-M193f0= 31acea0a531d106af6c Delivery options: https://9fans.topicbox.com/groups/9fans/subscription --17223916541.EE24.972286 Date: Tue, 30 Jul 2024 22:07:34 -0400 MIME-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
If you look at the top of the file you'll = see:

/*
 * Mirror one arena partition onto another.=20=20
 * Be careful to copy only new data.
 */

Now if you combine this with some of t= he information from venti(8):

          The data =
log is logically split into sections called arenas,
          typically sized for easy offline backup (e.g., 500MB).  A
          data log may comprise many disks, each storing one or more
          arenas.  Such disks are called arena partitions. Arena par-
          titions are filled in the order given in the configuration.
=

My best guess is that this is an incremental ba= ckup tool, where you give it a source and destination arena partition and t= he code looks at both, figures out the deltas, then copies over only what i= s needed. The venti code is a bit inscrutable and I'm no venti guy so t= ake this with a grain of salt.
= --17223916541.EE24.972286--