Hello, we installed Lustre 2.5.0 servers at a customer site and ran into massive stability problems. Because of this we would like to downgrade to 2.1.6 for now, until 2.5.0 is more mature. Is this possible? I tried to do 'tunefs.lustre --writeconf' on the MGT (formatted with 2.5.0) and mount it with the 2.1.6 kernel. It results in an immediate kernel crash with the console output shown below. Any suggestions? Best regards, Oliver --- Lustre: MGS MGS started LustreError: 5476:0:(mgc_request.c:76:mgc_name2resid()) missing name: -sptlrpc Lustre: 5528:0:(ldlm_lib.c:952:target_handle_connect()) MGS: connection from bd919a64-44f9-3a8d-88e8-be602f7d6de1@0@lo t0 exp (null) cur 1389192193 last 0 Lustre: MGC10.188.20.31@o2ib: Reactivating import LustreError: 5476:0:(mgc_request.c:286:config_log_add()) can't create sptlrpc log: -sptlrpc LustreError: 15b-f: MGC10.188.20.31@o2ib: The configuration from log '-params'failed from the MGS (-22). Make sure this client and the MGS are running compatible versions of Lustre. LustreError: 15c-8: MGC10.188.20.31@o2ib: The configuration from log '-params' failed (-22). This may be the result of communication errors between this node and the MGS, a bad configuration, or other errors. See the syslog for more information. BUG: unable to handle kernel paging request at 00000000deadbeef IP: [<ffffffff8127ebe9>] strnlen+0x9/0x40 PGD 638aca067 PUD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/module/ldiskfs/initstate CPU 4 Modules linked in: fsfilt_ldiskfs(U) exportfs mgs(U) mgc(U) ldiskfs(U) ipmi_devintf sunrpc cpufreq_ondemand acpi_cpufreq freq_table mperf lustre(U) lov(U) osc(U) lquota(U) mdc(U) fid(U) fld(U) ksocklnd(U) ko2iblnd(U) ptlrpc(U) obdclass(U) lnet(U) lvfs(U) libcfs(U) ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_addr ipv6 e1000e mlx4_ib ib_sa ib_mad ib_core mlx4_en mlx4_core mptsas mptscsih mptbase igb ptp pps_core microcode serio_raw i2c_i801 i2c_core iTCO_wdt iTCO_vendor_support ioatdma dca i7core_edac edac_core shpchp squashfs ext4 mbcache jbd2 raid1 sg sd_mod crc_t10dif mpt2sas(U) scsi_transport_sas raid_class ahci dm_multipath dm_mirror dm_region_hash dm_log dm_mod scsi_dh_rdac [last unloaded: scsi_wait_scan] Pid: 5476, comm: mount.lustre Not tainted 2.6.32-358.11.1.el6_lustre.x86_64 #1 Supermicro X8DTH-i/6/iF/6F/X8DTH RIP: 0010:[<ffffffff8127ebe9>] [<ffffffff8127ebe9>] strnlen+0x9/0x40 RSP: 0018:ffff880632073a58 EFLAGS: 00010286 RAX: ffffffff817a29dd RBX: ffff88061dc95000 RCX: 0000000000000002 RDX: 00000000deadbeef RSI: ffffffffffffffff RDI: 00000000deadbeef RBP: ffff880632073a58 R08: 0000000000000073 R09: 0000000000000004 R10: 0000000000000001 R11: ffff88033a243a6b R12: ffff88061dc94a34 R13: 00000000deadbeef R14: 00000000ffffffff R15: 0000000000000000 FS: 00007f62ee6ef700(0000) GS:ffff88034ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000deadbeef CR3: 0000000639dd2000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process mount.lustre (pid: 5476, threadinfo ffff880632072000, task ffff88063835b500) Stack: ffff880632073a98 ffffffff8127fea0 0000000000000000 ffff88061dc94a34 <d> ffffffffa051c8c7 ffffffffa051c8c5 ffff880632073c18 ffff88061dc95000 <d> ffff880632073b38 ffffffff812812e8 0000000000000004 0000000affffffff Call Trace: [<ffffffff8127fea0>] string+0x40/0x100 [<ffffffff812812e8>] vsnprintf+0x218/0x5e0 [<ffffffffa03ab19b>] ? cfs_set_ptldebug_header+0x2b/0xc0 [libcfs] [<ffffffffa03b65a3>] libcfs_debug_vmsg2+0x2c3/0xb60 [libcfs] [<ffffffffa04e4952>] ? lustre_process_log+0x812/0xad0 [obdclass] [<ffffffffa03b6e81>] libcfs_debug_msg+0x41/0x50 [libcfs] [<ffffffffa04ef0f1>] lustre_fill_super+0xd51/0x13a0 [obdclass] [<ffffffff8127f10a>] ? strlcpy+0x4a/0x60 [<ffffffffa04ee3a0>] ? lustre_fill_super+0x0/0x13a0 [obdclass] [<ffffffff8118433f>] get_sb_nodev+0x5f/0xa0 [<ffffffffa04dfad5>] lustre_get_sb+0x25/0x30 [obdclass] [<ffffffff8118395b>] vfs_kern_mount+0x7b/0x1b0 [<ffffffff81183b02>] do_kern_mount+0x52/0x130 [<ffffffff811a3ce2>] do_mount+0x2d2/0x8d0 [<ffffffff811a4370>] sys_mount+0x90/0xe0 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b Code: 66 90 48 83 c2 01 80 3a 00 75 f7 48 89 d0 48 29 f8 c9 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 f6 48 89 e5 74 2e <80> 3f 00 74 29 48 83 ee 01 48 89 f8 eb 12 66 0f 1f 84 00 00 00 RIP [<ffffffff8127ebe9>] strnlen+0x9/0x40 RSP <ffff880632073a58> CR2: 00000000deadbeef ---[ end trace bdafbd6d71d51ae3 ]--- Kernel panic - not syncing: Fatal exception Pid: 5476, comm: mount.lustre Tainted: G D --------------- 2.6.32-358.11.1.el6_lustre.x86_64 #1 Call Trace: [<ffffffff8150d7c8>] ? panic+0xa7/0x16f [<ffffffff815119f4>] ? oops_end+0xe4/0x100 [<ffffffff81046bfb>] ? no_context+0xfb/0x260 [<ffffffff81513996>] ? notifier_call_chain+0x16/0x80 [<ffffffff81046e85>] ? __bad_area_nosemaphore+0x125/0x1e0 [<ffffffff81513996>] ? notifier_call_chain+0x16/0x80 [<ffffffff81046fae>] ? bad_area+0x4e/0x60 [<ffffffff81047760>] ? __do_page_fault+0x3d0/0x480 [<ffffffff8106e485>] ? __call_console_drivers+0x75/0x90 [<ffffffff8100bb8e>] ? apic_timer_interrupt+0xe/0x20 [<ffffffff8106f241>] ? vprintk+0x251/0x560 [<ffffffff8151391e>] ? do_page_fault+0x3e/0xa0 [<ffffffff81510cd5>] ? page_fault+0x25/0x30 [<ffffffff8127ebe9>] ? strnlen+0x9/0x40 [<ffffffff8127fea0>] ? string+0x40/0x100 [<ffffffff812812e8>] ? vsnprintf+0x218/0x5e0 [<ffffffffa03ab19b>] ? cfs_set_ptldebug_header+0x2b/0xc0 [libcfs] [<ffffffffa03b65a3>] ? libcfs_debug_vmsg2+0x2c3/0xb60 [libcfs] [<ffffffffa04e4952>] ? lustre_process_log+0x812/0xad0 [obdclass] [<ffffffffa03b6e81>] ? libcfs_debug_msg+0x41/0x50 [libcfs] [<ffffffffa04ef0f1>] ? lustre_fill_super+0xd51/0x13a0 [obdclass] [<ffffffff8127f10a>] ? strlcpy+0x4a/0x60 [<ffffffffa04ee3a0>] ? lustre_fill_super+0x0/0x13a0 [obdclass] [<ffffffff8118433f>] ? get_sb_nodev+0x5f/0xa0 [<ffffffffa04dfad5>] ? lustre_get_sb+0x25/0x30 [obdclass] [<ffffffff8118395b>] ? vfs_kern_mount+0x7b/0x1b0 [<ffffffff81183b02>] ? do_kern_mount+0x52/0x130 [<ffffffff811a3ce2>] ? do_mount+0x2d2/0x8d0 [<ffffffff811a4370>] ? sys_mount+0x90/0xe0 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b -- Dr. Oliver Mangold System Analyst NEC Deutschland GmbH HPC Division Hessbrühlstraße 21b 70565 Stuttgart Germany Phone: +49 711 78055 13 Mail: oliver.mangold-2qtooGsX2/lWk0Htik3J/w@public.gmane.org