From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Durgin Subject: Re: Character limit for rbd block device Date: Mon, 26 Nov 2012 16:52:37 -0800 Message-ID: <50B40ED5.7050307@inktank.com> References: <50B404DA.50805@lamphost.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:57259 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757670Ab2K0AxZ (ORCPT ); Mon, 26 Nov 2012 19:53:25 -0500 Received: by mail-pb0-f46.google.com with SMTP id wy7so8445097pbc.19 for ; Mon, 26 Nov 2012 16:53:25 -0800 (PST) In-Reply-To: <50B404DA.50805@lamphost.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: brady Cc: ceph-devel@vger.kernel.org On 11/26/2012 04:10 PM, brady wrote: > Hello, > I have a general question. Is there a specific character limit for > rbd block devices? In attempting to map a block device with a name that > is 36 characters or more, I am getting the following error: > > rbd map (36+ character name) --user admin --secret /etc/ceph/keyring.key > add failed: (2) No such file or directory > > When using the same command to map a device with 35 characters or > less, the device is mapped as expected. Any insight into this issue > would be greatly appreciated. > > -Brady Which kernel version are you using? A year ago there was a 40-char limit on objects names in the kernel's libceph module, hence the failure at 36 char rbd image names (36 char name + ".rbd" is the format 1 header object name). This was extended to a 96-char limit in linux 3.2. There's no real limit in userspace still (http://tracker.newdream.net/issues/1701). Josh