From owner-freebsd-stable@FreeBSD.ORG Sat Aug 18 02:44:59 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3E58816A41A for ; Sat, 18 Aug 2007 02:44:59 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id B912E13C469 for ; Sat, 18 Aug 2007 02:44:58 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from list by ciao.gmane.org with local (Exim 4.43) id 1IMEJ2-0003TJ-KR for freebsd-stable@freebsd.org; Sat, 18 Aug 2007 04:44:52 +0200 Received: from 78-0-71-152.adsl.net.t-com.hr ([78.0.71.152]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 18 Aug 2007 04:44:52 +0200 Received: from ivoras by 78-0-71-152.adsl.net.t-com.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 18 Aug 2007 04:44:52 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-stable@freebsd.org From: Ivan Voras Date: Sat, 18 Aug 2007 04:44:24 +0200 Lines: 81 Message-ID: References: <31BB09D7-B58A-47AC-8DD1-6BB8141170D8@khera.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig59E9CE116831DC75CA9B2D17" X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: 78-0-71-152.adsl.net.t-com.hr User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) In-Reply-To: X-Enigmail-Version: 0.95.3 Sender: news Subject: Re: large RAID volume partition strategy X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Aug 2007 02:44:59 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig59E9CE116831DC75CA9B2D17 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Vivek Khera wrote: > My only fear of this is that once this system is in production, that's > pretty much it. Maintenance windows are about 1 year apart, usually > longer. Others will have to comment about that. I have only one 7-CURRENT in production (because of ZFS) and I had only one panic (in ZFS). But this machine is not heavily utilized. >> When you get there, you'll need to create 1 small RAID volume (<=3D 1 = GB) >> from which to boot (and probably use it for root) and use the rest for= >> whatever your choice is (doesn't really matter at this point). This is= >> because you can't have fdisk or bsdlabel partitions larger than 2 TB a= nd >> you can't boot from GPT. >=20 > So what your saying here is that I can't do either my option 1 or 2, bu= t > have to create smaller volumes exported as individual drives? Or just > that I can't do 1, because my case 2 I could make three 2Tb fdisk slice= s > which bsdlabel can then partition? fdisk and bsdlabels both have a limit: because of the way they store the data about the disk space they span, they can't store values that reference space > 2 TB. In particular, every partition must start at an offset <=3D 2 TB, and cannot be larger than 2 TB. In theory, the maximum you could do in "normal" (read on) circumstances is have a 4 TB volume partitioned into two 2 TB slices/partitions, and that's it. In practice, you can't usefully partition drives larger than 2 TB at all. There's one (also theoretical... I doubt anyone has tried it) way out of it: simulate a device with larger sector size through gnop(8). For example, if you use a 1 KB sector size you'll double all the limits (at least for bsdlabel, I think fdisk is stuck in 512-byte sectors) to 4 TB, for 4 KB sectors, to 16 TB). I know from experience that UFS can handle sectors up to 8 KB, other file systems might not. (ref: sys/disklabel.h: struct partition { /* the partition table */ u_int32_t p_size; /* number of sectors in partition= */ u_int32_t p_offset; /* starting sector */ u_int32_t p_fsize; /* filesystem basic fragment size= */ u_int8_t p_fstype; /* filesystem type, see below */ u_int8_t p_frag; /* filesystem fragments per block= */ u_int16_t p_cpg; /* filesystem cylinders per group= */ } d_partitions[MAXPARTITIONS]; /* actually may be more */ ) --------------enig59E9CE116831DC75CA9B2D17 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGxl0SldnAQVacBcgRAhYdAKCj/2umrVemDWCnUeoEQhBkEMFE7ACfXzZ8 gjz58wYAH6USCLufOaPVLaU= =ZwF3 -----END PGP SIGNATURE----- --------------enig59E9CE116831DC75CA9B2D17--