[HPDD-discuss] OST migration and upgrade questions

Hi, I have 2 or 3 questions more to ask here : - If I want move from 2 OSS A and B with 1 OST each (15+15TB) to 3 OSS with 1 OST each (10+10+10TB) using the same servers (+1 new), what's the best plan : - Add the new 10TB OST C, then move data from OST B to OST A and C, remove it, reformat with 10TB and readd it, then do the same with OST A ? - Should I disable the OST B prior moving datas ? - Should I run a specific command to exclude the OST or reformating the block device with the same OST name/number is enough ? - Something better ? - We are happily running Lustre 2.6 and 2.6.92 clients. But we need to upgrade our kernel version to fix a nasty bug making or nodes rebooting. I plan to upgrade kernel and Lustre client to 2.7 with the available RPMS. Is there any problem doing so ? - Do you suggest to upgrade servers to 2.7 as well ? Can it be done from 2.6.0 to 2.7.0 by just upgrading the binaries or is there specific tasks to run before ? Do we risk a data loss doing this ? Many thanks -- Jérome BECOT Administrateur Systèmes et Réseaux Molécules à visée Thérapeutique par des approches in Silico (MTi) Univ Paris Diderot, UMRS973 Inserm Case 013 Bât. Lamarck A, porte 412 35, rue Hélène Brion 75205 Paris Cedex 13 France Tel : 01 57 27 83 82