[lustre-discuss] Frequent, silent OSS hangs on multi-homed system
Hi, I'm love some ideas to debug what has become a frequent annoyance for us. At the high level, we're observing fairly frequent OSS hangs, with absolutely no console or logging activity. Our BMC watchdogs then reboot the OSS and ~6 minutes later everything is back in line. This has been an infrequent occurance on this system for a couple years, but has become much more frequent in recent months. I'd love any suggestions for either lustre/lnet or overall kernel tricks to up the logging level if possible to see if we can get some more useful output. Right now we're blind. More details below, and also what I'd characterize as uninformed speculation: -) overall system is (2x)MDS, (12x)OSS, (2x) Monitoring nodes of identical servers, network cards, etc... -) only difference is JBOD types, the OSS'es are connected to Supermicro 90-bay SC946ED-R2KJBOD. All other server hardware is identical. -) only the OSSes hang in this manner. I'm looking back, some seem more prone than others, but it's not obviously only a few. -) CentOS 7.6, lustre 2.10.8, ZFS 0.7.9 -) 2 active file systems, one is pure ZFS and the other ZFS/OSS with ldiskfs mdt -) Mellanox ConnectX3 FDR IB & 40GbE -) LSI 9300-8e HBA -) Lustre servers are triple-homed, they live on (2x) IB and (1x) 40GbE networks -) previously when we first moved to 2.10 we were bit hard and frequently by LU-10163 (which may or may not be relevant) -) The hangs don't correlate to any discrete event best I can tell. Importantly, we get no LBUGs or anything, which is different than the previous signature. -) We have definitely stepped up the traffic on the ethernet network this year. Whereas the primary I/O was previously just on the two IB networks, we are now taxing the ethernet as well with some regularity. Any thoughts are most welcome, and thanks! -Ben ___ lustre-discuss mailing list lustre-discuss@lists.lustre.org http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
Re: [lustre-discuss] Lustre/ZFS snapshots mount error
To follow up here, the LU appears to duplicate a DNE-tirggered issue as well. There is a patch available which resolved the issue for us when using 2.10.5 in our environment. For details and a link to the patch see https://jira.whamcloud.com/browse/LU-11411 -Ben On Sep 20, 2018, at 1:53 PM, Kirk, Benjamin (JSC-EG311) mailto:benjamin.k...@nasa.gov>> wrote: I just opened an LU on the issue https://jira.whamcloud.com/browse/LU-11411 for anyone interested. Thanks a lot! -Ben On Aug 27, 2018, at 4:56 PM, Andreas Dilger mailto:adil...@whamcloud.com>> wrote: It's probably best to file an LU ticket for this issue. It looks like there is something with the log processing at mount that is trying to modify the configuration files. I'm not sure whether that should be allowed or not. Does fab have the same MGS as fsA? Does it have the same MDS node as fsA? If it has a different MDS, you might consider to give it its own MGS as well. That doesn't have to be a separate MGS node, just a separate filesystem (ZFS fileset in the same zpool) on the MDS node. Cheers, Andreas On Aug 27, 2018, at 10:18, Kirk, Benjamin (JSC-EG311) mailto:benjamin.k...@nasa.gov>> wrote: Hi all, We have two filesystems, fsA & fsB (eadc below). Both of which get snapshots taken daily, rotated over a week. It’s a beautiful feature we’ve been using in production ever since it was introduced with 2.10. -) We’ve got Lustre/ZFS 2.10.4 on CentOS 7.5. -) Both fsA & fsB have changelogs active. -) fsA has combined mgt/mdt on a single ZFS filesystem. -) fsB has a single mdt on a single ZFS filesystem. -) for fsA, I have no issues mounting any of the snapshots via lctl. -) for fsB, I can mount the most three recent snapshots, then encounter errors: [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Mon mounted the snapshot eadc_AutoSS-Mon with fsname 3d40bbc [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Mon [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sun mounted the snapshot eadc_AutoSS-Sun with fsname 584c07a [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sun [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sat mounted the snapshot eadc_AutoSS-Sat with fsname 4e646fe [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sat [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Fri mount.lustre: mount metadata/meta-eadc@eadc_AutoSS-Fri at /mnt/eadc_AutoSS-Fri_MDT failed: Read-only file system Can't mount the snapshot eadc_AutoSS-Fri: Read-only file system The relevant bits from dmesg are [1353434.417762] Lustre: 3d40bbc-MDT: set dev_rdonly on this device [1353434.417765] Lustre: Skipped 3 previous similar messages [1353434.649480] Lustre: 3d40bbc-MDT: Imperative Recovery enabled, recovery window shrunk from 300-900 down to 150-900 [1353434.649484] Lustre: Skipped 3 previous similar messages [1353434.866228] Lustre: 3d40bbc-MDD: changelog on [1353434.866233] Lustre: Skipped 1 previous similar message [1353435.427744] Lustre: 3d40bbc-MDT: Connection restored to ...@tcp (at ...@tcp) [1353435.427747] Lustre: Skipped 23 previous similar messages [1353445.255899] Lustre: Failing over 3d40bbc-MDT [1353445.255903] Lustre: Skipped 3 previous similar messages [1353445.256150] LustreError: 11-0: 3d40bbc-OST-osc-MDT: operation ost_disconnect to node ...@tcp failed: rc = -107 [1353445.257896] LustreError: Skipped 23 previous similar messages [1353445.353874] Lustre: server umount 3d40bbc-MDT complete [1353445.353877] Lustre: Skipped 3 previous similar messages [1353475.302224] Lustre: 4e646fe-MDD: changelog on [1353475.302228] Lustre: Skipped 1 previous similar message [1353498.964016] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) 36ca26b-MDT-osd: someone try to start transaction under readonly mode, should be disabled. [1353498.967260] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) Skipped 1 previous similar message [1353498.968829] CPU: 6 PID: 25582 Comm: mount.lustre Kdump: loaded Tainted: P OE 3.10.0-862.6.3.el7.x86_64 #1 [1353498.968830] Hardware name: Supermicro SYS-6027TR-D71FRF/X9DRT, BIOS 3.2a 08/04/2015 [1353498.968832] Call Trace: [1353498.968841] [] dump_stack+0x19/0x1b [1353498.968851] [] osd_trans_create+0x38b/0x3d0 [osd_zfs] [1353498.968876] [] llog_destroy+0x1f4/0x3f0 [obdclass] [1353498.968887] [] llog_cat_reverse_process_cb+0x246/0x3f0 [obdclass] [1353498.968897] [] llog_reverse_process+0x38c/0xaa0 [obdclass] [1353498.968910] [] ? llog_cat_process_cb+0x4e0/0x4e0 [obdclass] [1353498.968922] [] llog_cat_reverse_process+0x179/0x270 [obdclass] [1353498.968932] [] ? llog_init_handle+0xd5/0x9a0 [obdclass] [1353498.968943] [] ? llog_open_create+0x78/0x320 [obdclass] [1353498.968949] [] ? mdd_root_get+0xf0/0xf0 [mdd] [1353498.968954] [] mdd_prepare+0x13ff/0x
Re: [lustre-discuss] Lustre/ZFS snapshots mount error
I just opened an LU on the issue https://jira.whamcloud.com/browse/LU-11411 for anyone interested. Thanks a lot! -Ben On Aug 27, 2018, at 4:56 PM, Andreas Dilger mailto:adil...@whamcloud.com>> wrote: It's probably best to file an LU ticket for this issue. It looks like there is something with the log processing at mount that is trying to modify the configuration files. I'm not sure whether that should be allowed or not. Does fab have the same MGS as fsA? Does it have the same MDS node as fsA? If it has a different MDS, you might consider to give it its own MGS as well. That doesn't have to be a separate MGS node, just a separate filesystem (ZFS fileset in the same zpool) on the MDS node. Cheers, Andreas On Aug 27, 2018, at 10:18, Kirk, Benjamin (JSC-EG311) mailto:benjamin.k...@nasa.gov>> wrote: Hi all, We have two filesystems, fsA & fsB (eadc below). Both of which get snapshots taken daily, rotated over a week. It’s a beautiful feature we’ve been using in production ever since it was introduced with 2.10. -) We’ve got Lustre/ZFS 2.10.4 on CentOS 7.5. -) Both fsA & fsB have changelogs active. -) fsA has combined mgt/mdt on a single ZFS filesystem. -) fsB has a single mdt on a single ZFS filesystem. -) for fsA, I have no issues mounting any of the snapshots via lctl. -) for fsB, I can mount the most three recent snapshots, then encounter errors: [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Mon mounted the snapshot eadc_AutoSS-Mon with fsname 3d40bbc [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Mon [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sun mounted the snapshot eadc_AutoSS-Sun with fsname 584c07a [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sun [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sat mounted the snapshot eadc_AutoSS-Sat with fsname 4e646fe [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sat [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Fri mount.lustre: mount metadata/meta-eadc@eadc_AutoSS-Fri at /mnt/eadc_AutoSS-Fri_MDT failed: Read-only file system Can't mount the snapshot eadc_AutoSS-Fri: Read-only file system The relevant bits from dmesg are [1353434.417762] Lustre: 3d40bbc-MDT: set dev_rdonly on this device [1353434.417765] Lustre: Skipped 3 previous similar messages [1353434.649480] Lustre: 3d40bbc-MDT: Imperative Recovery enabled, recovery window shrunk from 300-900 down to 150-900 [1353434.649484] Lustre: Skipped 3 previous similar messages [1353434.866228] Lustre: 3d40bbc-MDD: changelog on [1353434.866233] Lustre: Skipped 1 previous similar message [1353435.427744] Lustre: 3d40bbc-MDT: Connection restored to ...@tcp (at ...@tcp) [1353435.427747] Lustre: Skipped 23 previous similar messages [1353445.255899] Lustre: Failing over 3d40bbc-MDT [1353445.255903] Lustre: Skipped 3 previous similar messages [1353445.256150] LustreError: 11-0: 3d40bbc-OST-osc-MDT: operation ost_disconnect to node ...@tcp failed: rc = -107 [1353445.257896] LustreError: Skipped 23 previous similar messages [1353445.353874] Lustre: server umount 3d40bbc-MDT complete [1353445.353877] Lustre: Skipped 3 previous similar messages [1353475.302224] Lustre: 4e646fe-MDD: changelog on [1353475.302228] Lustre: Skipped 1 previous similar message [1353498.964016] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) 36ca26b-MDT-osd: someone try to start transaction under readonly mode, should be disabled. [1353498.967260] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) Skipped 1 previous similar message [1353498.968829] CPU: 6 PID: 25582 Comm: mount.lustre Kdump: loaded Tainted: P OE 3.10.0-862.6.3.el7.x86_64 #1 [1353498.968830] Hardware name: Supermicro SYS-6027TR-D71FRF/X9DRT, BIOS 3.2a 08/04/2015 [1353498.968832] Call Trace: [1353498.968841] [] dump_stack+0x19/0x1b [1353498.968851] [] osd_trans_create+0x38b/0x3d0 [osd_zfs] [1353498.968876] [] llog_destroy+0x1f4/0x3f0 [obdclass] [1353498.968887] [] llog_cat_reverse_process_cb+0x246/0x3f0 [obdclass] [1353498.968897] [] llog_reverse_process+0x38c/0xaa0 [obdclass] [1353498.968910] [] ? llog_cat_process_cb+0x4e0/0x4e0 [obdclass] [1353498.968922] [] llog_cat_reverse_process+0x179/0x270 [obdclass] [1353498.968932] [] ? llog_init_handle+0xd5/0x9a0 [obdclass] [1353498.968943] [] ? llog_open_create+0x78/0x320 [obdclass] [1353498.968949] [] ? mdd_root_get+0xf0/0xf0 [mdd] [1353498.968954] [] mdd_prepare+0x13ff/0x1c70 [mdd] [1353498.968966] [] mdt_prepare+0x57/0x3b0 [mdt] [1353498.968983] [] server_start_targets+0x234d/0x2bd0 [obdclass] [1353498.968999] [] ? class_config_dump_handler+0x7e0/0x7e0 [obdclass] [1353498.969012] [] server_fill_super+0x109d/0x185a [obdclass] [1353498.969025] [] lustre_fill_super+0x328/0x950 [obdclass] [1353498.969038] [] ? lustre_common_p
Re: [lustre-discuss] lustre-discuss Digest, Vol 150, Issue 14
I will attempt to create an LU with our specific information. I’ve not done that before, I believe I’ll need an account somewhere?? > On Sep 11, 2018, at 7:02 AM, "lustre-discuss-requ...@lists.lustre.org" > wrote: > > Send lustre-discuss mailing list submissions to >lustre-discuss@lists.lustre.org > > To subscribe or unsubscribe via the World Wide Web, visit >http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org > or, via email, send a message with subject or body 'help' to >lustre-discuss-requ...@lists.lustre.org > > You can reach the person managing the list at >lustre-discuss-ow...@lists.lustre.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of lustre-discuss digest..." > > > Today's Topics: > > 1. Re: Lustre/ZFS snapshots mount error (Yong, Fan) > > > -- > > Message: 1 > Date: Tue, 11 Sep 2018 12:00:00 + > From: "Yong, Fan" > To: Robert Redl , >"lustre-discuss@lists.lustre.org" > Subject: Re: [lustre-discuss] Lustre/ZFS snapshots mount error > Message-ID: ><7fb055e0b36b6f4eb93e637e0640a56fcc040...@fmsmsx125.amr.corp.intel.com> > > Content-Type: text/plain; charset="utf-8" > > Changelog is just one of the users for llog. There are many other users for > llog. Means that even if without changelog, it is still possible to hit such > trouble. So running robinhood when making snapshot may increase such race > possibility, but disabling robinhood does not means resolved the issue. The > final solution should be the enhancement of snapshot-mount logic. > > I did not find related LU ticket for this issue. > > -- > Cheers, > Nasf > > From: lustre-discuss [mailto:lustre-discuss-boun...@lists.lustre.org] On > Behalf Of Robert Redl > Sent: Tuesday, September 11, 2018 6:54 PM > To: lustre-discuss@lists.lustre.org > Subject: Re: [lustre-discuss] Lustre/ZFS snapshots mount error > > > Thanks for the fast reply! If I understood correctly, it is currently not > possible to use the changelog feature together with the snapshot feature, > right? > > Is there already a LU-Ticket about that? > > Cheers, > Robert > > On 09/10/2018 02:57 PM, Yong, Fan wrote: > It is suspected that there were some llog to be handled when the snapshot was > making Then when mount-up such snapshot, some conditions trigger the llog > cleanup/modification automatically. So it is not related with your actions > when mount the snapshot. Since we cannot control the system status when > making the snapshot, then we have to skip llog related cleanup/modification > against the snapshot when mount the snapshot. Such ?skip? related logic is > just what we need. > > Cheers, > Nasf > From: lustre-discuss [mailto:lustre-discuss-boun...@lists.lustre.org] On > Behalf Of Robert Redl > Sent: Saturday, September 8, 2018 9:04 PM > To: lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> > Subject: Re: [lustre-discuss] Lustre/ZFS snapshots mount error > > > Dear All, > > we have a similar setup with Lustre on ZFS and we make regular use of > snapshots for the purpose of backups (backups on tape use snapshots as > source). We would like to use robinhood in future and the question is now how > to do it. > > Would it be a workaround to disable the robinhood daemon temporary during the > mount process? > Does the problem only occur when changelogs are consumed during the process > of mounting a snapshot? Or is it also a problem when changelogs are consumed > while the snapshot remains mounted (which is for us typically several hours)? > Is there already an LU-ticket about this issue? > > Thanks! > Robert > -- > Dr. Robert Redl > Scientific Programmer, "Waves to Weather" (SFB/TRR165) > Meteorologisches Institut > Ludwig-Maximilians-Universit?t M?nchen > Theresienstr. 37, 80333 M?nchen, Germany > Am 03.09.2018 um 08:16 schrieb Yong, Fan: > I would say that it is not your operations order caused trouble. Instead, it > is related with the snapshot mount logic. As mentioned in former reply, we > need some patch for the llog logic to avoid modifying llog under snapshot > mode. > > > -- > Cheers, > Nasf > From: Kirk, Benjamin (JSC-EG311) [mailto:benjamin.k...@nasa.gov] > Sent: Tuesday, August 28, 2018 7:53 PM > To: lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> > Cc: Andreas Dilger <mailto:adil...@whamcloud.com>; > Yong, Fan <mailto:fan.y...@intel.com> > Subject: Re: [lu
Re: [lustre-discuss] Lustre/ZFS snapshots mount error
The MDS situation is very basic: active/passive mds0/mds1 for both fas & fsB. fsA has the combined msg/mdt in a single zfs filesystem, and fsB has its own mdt in a separate zfs filesystem. mds0 is primary for all. fsA & fsB DO both have changelogs enabled to feed robinhood databases. What’s the recommended procedure here we should follow before mounting the snapshots? 1) disable changelogs on the active mdt’s (this will compromise robinhood, requiring a rescan…), or 2) temporarily halt changelog consumption / cleanup (e.g. stop robinhood in our case) and then mount the snapshot? Thanks for the help! -- Benjamin S. Kirk, Ph.D. NASA Lyndon B. Johnson Space Center Acting Chief, Aeroscience & Flight Mechanics Division On Aug 27, 2018, at 7:33 PM, Yong, Fan mailto:fan.y...@intel.com>> wrote: According to the stack trace, someone was trying to cleanup old empty llogs during mount the snapshot. We do NOT allow any modification during mount snapshot; otherwise, it will trigger ZFS backend BUG(). That is why we add LASSERT() when start the transaction. One possible solution is that, we can add some check in the llog logic to avoid modifying llog under snapshot mode. -- Cheers, Nasf -Original Message- From: lustre-discuss [mailto:lustre-discuss-boun...@lists.lustre.org] On Behalf Of Andreas Dilger Sent: Tuesday, August 28, 2018 5:57 AM To: Kirk, Benjamin (JSC-EG311) mailto:benjamin.k...@nasa.gov>> Cc: lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> Subject: Re: [lustre-discuss] Lustre/ZFS snapshots mount error It's probably best to file an LU ticket for this issue. It looks like there is something with the log processing at mount that is trying to modify the configuration files. I'm not sure whether that should be allowed or not. Does fab have the same MGS as fsA? Does it have the same MDS node as fsA? If it has a different MDS, you might consider to give it its own MGS as well. That doesn't have to be a separate MGS node, just a separate filesystem (ZFS fileset in the same zpool) on the MDS node. Cheers, Andreas On Aug 27, 2018, at 10:18, Kirk, Benjamin (JSC-EG311) mailto:benjamin.k...@nasa.gov>> wrote: Hi all, We have two filesystems, fsA & fsB (eadc below). Both of which get snapshots taken daily, rotated over a week. It’s a beautiful feature we’ve been using in production ever since it was introduced with 2.10. -) We’ve got Lustre/ZFS 2.10.4 on CentOS 7.5. -) Both fsA & fsB have changelogs active. -) fsA has combined mgt/mdt on a single ZFS filesystem. -) fsB has a single mdt on a single ZFS filesystem. -) for fsA, I have no issues mounting any of the snapshots via lctl. -) for fsB, I can mount the most three recent snapshots, then encounter errors: [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Mon mounted the snapshot eadc_AutoSS-Mon with fsname 3d40bbc [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Mon [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sun mounted the snapshot eadc_AutoSS-Sun with fsname 584c07a [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sun [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sat mounted the snapshot eadc_AutoSS-Sat with fsname 4e646fe [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sat [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Fri mount.lustre: mount metadata/meta-eadc@eadc_AutoSS-Fri at /mnt/eadc_AutoSS-Fri_MDT failed: Read-only file system Can't mount the snapshot eadc_AutoSS-Fri: Read-only file system The relevant bits from dmesg are [1353434.417762] Lustre: 3d40bbc-MDT: set dev_rdonly on this device [1353434.417765] Lustre: Skipped 3 previous similar messages [1353434.649480] Lustre: 3d40bbc-MDT: Imperative Recovery enabled, recovery window shrunk from 300-900 down to 150-900 [1353434.649484] Lustre: Skipped 3 previous similar messages [1353434.866228] Lustre: 3d40bbc-MDD: changelog on [1353434.866233] Lustre: Skipped 1 previous similar message [1353435.427744] Lustre: 3d40bbc-MDT: Connection restored to ...@tcp (at ...@tcp) [1353435.427747] Lustre: Skipped 23 previous similar messages [1353445.255899] Lustre: Failing over 3d40bbc-MDT [1353445.255903] Lustre: Skipped 3 previous similar messages [1353445.256150] LustreError: 11-0: 3d40bbc-OST-osc-MDT: operation ost_disconnect to node ...@tcp failed: rc = -107 [1353445.257896] LustreError: Skipped 23 previous similar messages [1353445.353874] Lustre: server umount 3d40bbc-MDT complete [1353445.353877] Lustre: Skipped 3 previous similar messages [1353475.302224] Lustre: 4e646fe-MDD: changelog on [1353475.302228] Lustre: Skipped 1 previous similar message [1353498.964016] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) 36ca26b-MDT-osd: someone try to start transaction under readonly mode, should be dis
[lustre-discuss] Lustre/ZFS snapshots mount error
Hi all, We have two filesystems, fsA & fsB (eadc below). Both of which get snapshots taken daily, rotated over a week. It’s a beautiful feature we’ve been using in production ever since it was introduced with 2.10. -) We’ve got Lustre/ZFS 2.10.4 on CentOS 7.5. -) Both fsA & fsB have changelogs active. -) fsA has combined mgt/mdt on a single ZFS filesystem. -) fsB has a single mdt on a single ZFS filesystem. -) for fsA, I have no issues mounting any of the snapshots via lctl. -) for fsB, I can mount the most three recent snapshots, then encounter errors: [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Mon mounted the snapshot eadc_AutoSS-Mon with fsname 3d40bbc [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Mon [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sun mounted the snapshot eadc_AutoSS-Sun with fsname 584c07a [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sun [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Sat mounted the snapshot eadc_AutoSS-Sat with fsname 4e646fe [root@hpfs-fsl-mds0 ~]# lctl snapshot_umount -F eadc -n eadc_AutoSS-Sat [root@hpfs-fsl-mds0 ~]# lctl snapshot_mount -F eadc -n eadc_AutoSS-Fri mount.lustre: mount metadata/meta-eadc@eadc_AutoSS-Fri at /mnt/eadc_AutoSS-Fri_MDT failed: Read-only file system Can't mount the snapshot eadc_AutoSS-Fri: Read-only file system The relevant bits from dmesg are [1353434.417762] Lustre: 3d40bbc-MDT: set dev_rdonly on this device [1353434.417765] Lustre: Skipped 3 previous similar messages [1353434.649480] Lustre: 3d40bbc-MDT: Imperative Recovery enabled, recovery window shrunk from 300-900 down to 150-900 [1353434.649484] Lustre: Skipped 3 previous similar messages [1353434.866228] Lustre: 3d40bbc-MDD: changelog on [1353434.866233] Lustre: Skipped 1 previous similar message [1353435.427744] Lustre: 3d40bbc-MDT: Connection restored to ...@tcp (at ...@tcp) [1353435.427747] Lustre: Skipped 23 previous similar messages [1353445.255899] Lustre: Failing over 3d40bbc-MDT [1353445.255903] Lustre: Skipped 3 previous similar messages [1353445.256150] LustreError: 11-0: 3d40bbc-OST-osc-MDT: operation ost_disconnect to node ...@tcp failed: rc = -107 [1353445.257896] LustreError: Skipped 23 previous similar messages [1353445.353874] Lustre: server umount 3d40bbc-MDT complete [1353445.353877] Lustre: Skipped 3 previous similar messages [1353475.302224] Lustre: 4e646fe-MDD: changelog on [1353475.302228] Lustre: Skipped 1 previous similar message [1353498.964016] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) 36ca26b-MDT-osd: someone try to start transaction under readonly mode, should be disabled. [1353498.967260] LustreError: 25582:0:(osd_handler.c:341:osd_trans_create()) Skipped 1 previous similar message [1353498.968829] CPU: 6 PID: 25582 Comm: mount.lustre Kdump: loaded Tainted: P OE 3.10.0-862.6.3.el7.x86_64 #1 [1353498.968830] Hardware name: Supermicro SYS-6027TR-D71FRF/X9DRT, BIOS 3.2a 08/04/2015 [1353498.968832] Call Trace: [1353498.968841] [] dump_stack+0x19/0x1b [1353498.968851] [] osd_trans_create+0x38b/0x3d0 [osd_zfs] [1353498.968876] [] llog_destroy+0x1f4/0x3f0 [obdclass] [1353498.968887] [] llog_cat_reverse_process_cb+0x246/0x3f0 [obdclass] [1353498.968897] [] llog_reverse_process+0x38c/0xaa0 [obdclass] [1353498.968910] [] ? llog_cat_process_cb+0x4e0/0x4e0 [obdclass] [1353498.968922] [] llog_cat_reverse_process+0x179/0x270 [obdclass] [1353498.968932] [] ? llog_init_handle+0xd5/0x9a0 [obdclass] [1353498.968943] [] ? llog_open_create+0x78/0x320 [obdclass] [1353498.968949] [] ? mdd_root_get+0xf0/0xf0 [mdd] [1353498.968954] [] mdd_prepare+0x13ff/0x1c70 [mdd] [1353498.968966] [] mdt_prepare+0x57/0x3b0 [mdt] [1353498.968983] [] server_start_targets+0x234d/0x2bd0 [obdclass] [1353498.968999] [] ? class_config_dump_handler+0x7e0/0x7e0 [obdclass] [1353498.969012] [] server_fill_super+0x109d/0x185a [obdclass] [1353498.969025] [] lustre_fill_super+0x328/0x950 [obdclass] [1353498.969038] [] ? lustre_common_put_super+0x270/0x270 [obdclass] [1353498.969041] [] mount_nodev+0x4f/0xb0 [1353498.969053] [] lustre_mount+0x38/0x60 [obdclass] [1353498.969055] [] mount_fs+0x3e/0x1b0 [1353498.969060] [] vfs_kern_mount+0x67/0x110 [1353498.969062] [] do_mount+0x1ef/0xce0 [1353498.969066] [] ? kmem_cache_alloc_trace+0x3c/0x200 [1353498.969069] [] SyS_mount+0x83/0xd0 [1353498.969074] [] system_call_fastpath+0x1c/0x21 [1353498.969079] LustreError: 25582:0:(llog_cat.c:1027:llog_cat_reverse_process_cb()) 36ca26b-MDD: fail to destroy empty log: rc = -30 [1353498.970785] CPU: 6 PID: 25582 Comm: mount.lustre Kdump: loaded Tainted: P OE 3.10.0-862.6.3.el7.x86_64 #1 [1353498.970786] Hardware name: Supermicro SYS-6027TR-D71FRF/X9DRT, BIOS 3.2a 08/04/2015 [1353498.970787] Call Trace: [1353498.970790] [] dump_stack+0x19/0x1b
