From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Ramesh Subject: Re: mdadm --grow with --backup-file does not create backupfile? Date: Sun, 12 Oct 2014 20:49:21 -0500 Message-ID: <543B2FA1.4030106@gmail.com> References: <543B2A2D.9080407@gmail.com> <20141013123914.04b960ed@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: <20141013123914.04b960ed@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: Linux Raid List-Id: linux-raid.ids Good to know. Thanks. Ramesh On 10/12/2014 08:39 PM, NeilBrown wrote: > On Sun, 12 Oct 2014 20:26:05 -0500 Ram Ramesh wrote: > >> I added a new disk and grew my raid6 md0 with the following command line >> >> sudo mdadm --grow --raid-devices=5 >> --backup-file=/root/grow_md0.bkp_file --layout=normalise /dev/md0 >> >> I got a response that stated that mdadm needed to backup 384K of data. >> However, when I checked after about 5min there was no backup file. Is >> this expected? > Yes. > > When increasing the size of an array, the backup file is needed for a tiny > fraction of a second at the start. > When decreasing the size it is needed for a tiny fraction if a second at the > end. > When the size isn't changed it is needed for the entire time. > > ... unless you have a new kernel and a new mdadm, and then the backup file > isn't needed. > > NeilBrown > > > >> 386 > sudo ls /root >> >> 387 > sudo ls /root/grow_md0.bkp_file >> ls: cannot access /root/grow_md0.bkp_file: No such file or directory >> >> Ramesh >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html