From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: How do people deal with disk size variations? Date: Wed, 13 May 2009 11:09:52 +0200 Message-ID: <4A0A8E60.8030702@rabbit.us> References: <4A0A89DE.4070502@eyal.emu.id.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4A0A89DE.4070502@eyal.emu.id.au> Sender: linux-raid-owner@vger.kernel.org To: Eyal Lebedinsky Cc: linux-raid List-Id: linux-raid.ids Eyal Lebedinsky wrote: > I have a 5-disk raid5. I notice that the five identical disks, which also > list identical LBA numbers on the label, do not show the same size when > queried. One is reporting (smart - it should tell the truth from the disk > pov) a smaller size. > > One disk reports > User Capacity: 1,000,203,804,160 bytes > and the other four > User Capacity: 1,000,204,886,016 bytes > > Luckily I always build a raid on partitions so this difference is > irrelevant being in the slack past the partition end. > > However, if I managed to use the whole disk, the raid will be as large as > the smallest disk. What happens when I replace a disk and get an even > smaller replacement one? > > Do people always leave unused space at the end? Do you expect disks from > the same exact model to have exactly the same usable size? I always leave about 2gb off a disk, regardless of if I use a full disk or partitions. Considering you are dealing with terabyte drives here, your question seems rather strange... Cheers