From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giovanni Tessore Subject: Re: recommending RAID6 over RAID5 when doing mdadm --create Date: Tue, 12 Nov 2013 08:12:37 +0100 Message-ID: <5281D4E5.6080304@texsoft.it> References: <52809BC5.2010605@hardwarefreak.com> <20131112135243.285834fa@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131112135243.285834fa@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 11/12/2013 03:52 AM, NeilBrown wrote: > On Mon, 11 Nov 2013 02:56:37 -0600 Stan Hoeppner > wrote: > >> On 11/11/2013 1:44 AM, Mikael Abrahamsson wrote: >> >>> I believe this has been discussed before, but I would like to bring it >>> up again. >>> >>> I would like to see mdadm recommend RAID6 over RAID6 when using >>> component drives that are 500GB or larger and ask if the user is really >>> sure about using RAID5, plus a pointer to a webpage on the wiki >>> informing the user about the trouble with RAID5 on large volumes with >>> consumer or prosumer drives. >>> >>> I am willing to contribute text to the webpage being pointed to. >> Wikis change to regularly, too easily. Networks can be down at times, >> often the worst times. See Murphy's Law. >> >> It would be better to put this information in mdadm(8) and refer the >> user there. >> > .. or in md(4) maybe. > > If anyone wants to run with this and send me a patch (for code and > documentation) I would be very likely to apply it. > > NeilBrown That issue (RAID5 going fully down during resync of degraded array if read errors occur) hasn't been addressed by the badblocks log feature available in later kernels and mdadm ? Yet, it is not clear to me if the fetaure is fully implemented and operational. Regards Giovanni