From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: Re: RAID needs more to survive a power hit, different /boot layout for example (was Re: draft howto on making raids for surviving a disk crash) Date: Mon, 04 Feb 2008 12:27:29 +0300 Message-ID: <47A6DA81.3030008@msgid.tls.msk.ru> References: <47A612BE.5050707@pobox.com> <47A623EE.4050305@msgid.tls.msk.ru> <47A62A17.70101@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <47A62A17.70101@pobox.com> Sender: linux-raid-owner@vger.kernel.org To: Moshe Yudkowsky Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Moshe Yudkowsky wrote: [] > But that's *exactly* what I have -- well, 5GB -- and which failed. I've > modified /etc/fstab system to use data=journal (even on root, which I > thought wasn't supposed to work without a grub option!) and I can > power-cycle the system and bring it up reliably afterwards. Note also that data=journal effectively doubles the write time. It's a bit faster for small writes (because all writes are first done into the journal, i.e. into the same place, so no seeking is needed), but for larger writes, the journal will become full and data found in it needs to be written to proper place, to free space for new data. Here, if you'll continue writing, you will have more than 2x speed degradation, because of a) double writes, and b) more seeking. /mjt