From mboxrd@z Thu Jan 1 00:00:00 1970 From: White, Cliff Date: Fri, 11 Oct 2013 17:41:33 +0000 Subject: [Lustre-devel] Kernel crash from "mkfs.lustre --index" setting In-Reply-To: Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org On 10/11/13 10:11 AM, "Wendy Cheng" wrote: >This panic seems to be generic regardless the platform, though I'm >actually on Intel Xeon Phi Lustre (client) nodes. > >New to Lustre, I mistakenly thought the "index" option of mkfs.lustre >was for software raid so I formatted one of the server disks as the >following: > >server> mkfs.lustre --reformat --fsname=lus1 --mgs --mdt --index=1 >/dev/sdd1 >server> mkfs.lustre --reformat --ost --fsname=lus1 >--mgsnode=192.168.20.46 at o2ib0 --index=1 /dev/sde1 > >The client mount immediately crashed at lmv_get_info(). The attached >patch fixed that particular panic ... but unfortunately crashed at an >assertion further down the path. I'll be travelling next week so might >give up pursuing this issue. The disks are now subsequently >re-formatted with index=0 - things seem to work fine and performance >numbers collected. Three questions here: > >1. What is this "index" option all about ? >2. Does the problem worth being fixed ? Or is it a user error ? >3. The performance numbers (again, NOT Xeon Phi specific) surprise me. >Would this list be a good place to ask questions ? > >-- Wendy > 1. --index is used to enumerate OSTs and MDT, when using DNE. The index MUST be unique, and indexes must not have gaps. So, you should do this: server> mkfs.lustre --reformat --fsname=lus1 --mgs --mdt --index=0 /dev/sdd1 /* First MDT */ server> mkfs.lustre --reformat --ost --fsname=lus1 --mgsnode=192.168.20.46 at o2ib0 --index=0 /dev/sde1 /* first OST */ If you add a second OST partition: server> mkfs.lustre --reformat --ost --fsname=lus1 --mgsnode=192.168.20.46 at o2ib0 --index=1 /dev/sdfoo /* second OST */ And a third: server> mkfs.lustre --reformat --ost --fsname=lus1 --mgsnode=192.168.20.46 at o2ib0 --index=2 /dev/sdbar /* third OST */ 2.- You must fix this, or things won't work. I would suggest starting again, and doing a reformat Etc,etc 3. Surprise you how? HPDD-discuss is likely a better list for these sorts of questions, lustre-devel is for code development. Cliffw