From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Goryachev Subject: Re: mdadm: /dev/md0 has been started with 1 drive (out of 2). Date: Tue, 05 Nov 2013 22:39:50 +1100 Message-ID: <5278D906.4010301@websitemanagers.com.au> References: <5278C2A6.7060005@websitemanagers.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Ivan Lezhnjov IV Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 05/11/13 22:32, Ivan Lezhnjov IV wrote: > I checked out mdadm man page, read some pages on the web, and well, what bitmap chunk size should I go for considering these are WD Elements 2TB drives (what kind of technical information about these drives are relevant when considering a bitmap chunk size?) > Other users might have a better suggestion, but I usually just use the default. The only time this will matter is if performance is really important to you, then you can force a larger bitmap chunk size which will result in more data being copied during a resync, but less bitmap updates, therefore possibly better performance. I mainly use it where I can't afford the 30 hours of resync time. Regards, Adam > Ivan > > On Nov 5, 2013, at 12:04 PM, Adam Goryachev wrote: > >> Personally, I would also do: >> mdadm --grow /dev/md0 --bitmap=internal >> This means next time you have a similar issue, when you add the older >> drive, it will only sync the small parts of the drive that are out of >> date, instead of the entire drive. -- Adam Goryachev Website Managers www.websitemanagers.com.au