Date: Sun, 3 Apr 2011 12:21:55 +0200 From: "Patrick M. Hausen" <hausen@punkt.de> To: Jeremy Chadwick <freebsd@jdc.parodius.com> Cc: FreeBSD Stable <freebsd-stable@freebsd.org> Subject: Re: ahci.ko in RELENG_8_2, what about atacontrol cap? Message-ID: <3B6BFB01-3AC4-432B-8713-6CED09FFF9A2@punkt.de> In-Reply-To: <20110402094038.GA3521@icarus.home.lan> References: <EFA22697-4025-4E8B-B20A-C0142926FE1F@punkt.de> <20110402094038.GA3521@icarus.home.lan>
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Hello, Am 02.04.2011 um 11:40 schrieb Jeremy Chadwick: > You want "camcontrol identify adaX". DO NOT confuse this with > "camcontrol inquiry adaX" (this won't work). >=20 > identify =3D for ATA > inquiry =3D for SCSI Works perfectly, but I just noticed one really odd thing: 1. boot without ahci.ko: nas-pmh# atacontrol cap ad4 ... write cache yes yes 2. boot with ahci.ko: nas-pmh# camcontrol identify ada0 ... write cache yes no Well? ;-) The system is a HP NL36 - I just found a couple of articles mentioning that the default setting in the BIOS setup was write cache disabled. I can check that in the next couple of days when I take the machine back to the lab (no monitor/keyboard at my home office). I'd prefer a way to make sure write cache is enabled via some tuning from FreeBSD. The disks are dedicated to a raidz2, so from what I found around the net, write cache should not pose a major problem. Of course, one will lose _some_ data at a power outage - what I want to avoid for home office use is a completely lost file system. Losing the last time machine backup of my Mac is tolerable. Thanks, Patrick --=20 punkt.de GmbH * Kaiserallee 13a * 76133 Karlsruhe Tel. 0721 9109 0 * Fax 0721 9109 100 info@punkt.de http://www.punkt.de Gf: J=FCrgen Egeling AG Mannheim 108285
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