I posted once with a similar issue/title. This is a new setup. I’m using Microceph + LXD (6/stable) on the latest Ubuntu Server (26.04). There are three hosts, and I’m wondering if the Ubuntu Fan is being mean again? I have shutdown the servers for now since they become unresponsive. But I do have the terminal windows that were tailing /var/log/syslog live, so I can grab other details across the three hosts.
Generally, once Ubuntu Server was setup, I was able to configure Microceph without issue. (Beyond stupid human ones where I make typos in the device names). That was stable over night. I then found that I couldn’t use LXD 5.21/stable (due to some issue regarding the specific core libraries utilized) so I switched to 6/stable and (per a prior ticket is 6.8-5a1a287).
Sorry in advance for the copy/paste. I did try to find sections that had the “cut here” and “end trace” messages. There are plenty of others that don’t have that formatting.
This is from hydra1:
2026-05-20T22:13:40.072391+00:00 hydra1 kernel: NOHZ tick-stop error: local softirq work is pending, handler #80!!!
2026-05-20T22:14:42.145432+00:00 hydra1 kernel: ------------[ cut here ]------------
2026-05-20T22:14:42.145451+00:00 hydra1 kernel: Voluntary context switch within RCU read-side critical section!
2026-05-20T22:14:42.145453+00:00 hydra1 kernel: WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x238/0x2a0, CPU#10: swapper/10/0
2026-05-20T22:14:42.145456+00:00 hydra1 kernel: Modules linked in: nft_masq nft_chain_nat vxlan ip6_udp_tunnel udp_tunnel dummy bridge stp llc zfs(PO) spl(O) ebtable_filter ebtables ip6table_raw ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables nf_tables vhost_vsock vmw_vsock_virtio_transport_common vhost vhost_iotlb vsock qrtr cfg80211 nova_core binfmt_misc nls_iso8859_1 intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_alc662 snd_hda_codec_realtek_lib snd_hda_codec_nvhdmi snd_hda_codec_generic snd_hda_codec_hdmi kvm think_lmi snd_hda_intel irqbypass rapl snd_hda_codec ee1004 intel_cstate wmi_bmof firmware_attributes_class intel_wmi_thunderbolt snd_hda_core nouveau rtsx_usb_ms snd_intel_dspcfg memstick i2c_i801 snd_intel_sdw_acpi gpu_sched i2c_smbus snd_hwdep i2c_mux intel_pch_thermal snd_pcm mei_me drm_gpuvm
2026-05-20T22:14:42.145461+00:00 hydra1 kernel: mxm_wmi lpc_ich snd_timer drm_ttm_helper mei snd ttm drm_exec soundcore drm_display_helper cec rc_core i2c_algo_bit video mac_hid sch_fq_codel rbd libceph krb5enc authenc camellia_generic camellia_aesni_avx2 camellia_aesni_avx_x86_64 camellia_x86_64 cmac krb5 dm_crypt efi_pstore dm_multipath nfnetlink uas usb_storage ghash_clmulni_intel e1000e ahci libahci pata_acpi wmi rtsx_usb_sdmmc rtsx_usb dm_mirror dm_region_hash dm_log msr dmi_sysfs autofs4 aesni_intel
2026-05-20T22:14:42.145464+00:00 hydra1 kernel: CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: P O 7.0.0-15-generic #15-Ubuntu PREEMPT(lazy)
2026-05-20T22:14:42.145467+00:00 hydra1 kernel: Tainted: [P]=PROPRIETARY_MODULE, [O]=OOT_MODULE
2026-05-20T22:14:42.145469+00:00 hydra1 kernel: Hardware name: LENOVO 30B4S16S00/102F, BIOS S00KT73A 05/24/2022
2026-05-20T22:14:42.145471+00:00 hydra1 kernel: RIP: 0010:rcu_note_context_switch+0x238/0x2a0
2026-05-20T22:14:42.145495+00:00 hydra1 kernel: Code: 88 09 00 00 48 8d 93 88 09 00 00 48 39 d1 75 6a 48 23 47 20 74 4d 4c 89 e6 e8 64 f3 ff ff e9 46 fe ff ff 48 8d 3d 28 07 9a 02 <67> 48 0f b9 3a e9 02 fe ff ff 49 8b 7c 24 20 48 89 7d e0 e8 e0 bf
2026-05-20T22:14:42.145498+00:00 hydra1 kernel: RSP: 0018:ffffd0860018fe40 EFLAGS: 00010002
2026-05-20T22:14:42.145500+00:00 hydra1 kernel: RAX: 0000000000000001 RBX: ffff8ccf00e52a80 RCX: 0000000000000000
2026-05-20T22:14:42.145502+00:00 hydra1 kernel: RDX: 0000000000000000 RSI: ffffffff8b720c32 RDI: ffffffff8cedf740
2026-05-20T22:14:42.145504+00:00 hydra1 kernel: RBP: ffffd0860018fe60 R08: 0000000000000000 R09: 0000000000000000
2026-05-20T22:14:42.145506+00:00 hydra1 kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffff8ce67fd34540
2026-05-20T22:14:42.145508+00:00 hydra1 kernel: R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
2026-05-20T22:14:42.145510+00:00 hydra1 kernel: FS: 0000000000000000(0000) GS:ffff8ce6f2900000(0000) knlGS:0000000000000000
2026-05-20T22:14:42.145512+00:00 hydra1 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2026-05-20T22:14:42.145514+00:00 hydra1 kernel: CR2: 0000000000000000 CR3: 0000000d6e844006 CR4: 00000000003726f0
2026-05-20T22:14:42.145516+00:00 hydra1 kernel: Call Trace:
2026-05-20T22:14:42.145517+00:00 hydra1 kernel: <TASK>
2026-05-20T22:14:42.145519+00:00 hydra1 kernel: __schedule+0xcf/0x630
2026-05-20T22:14:42.145521+00:00 hydra1 kernel: schedule_idle+0x22/0x40
2026-05-20T22:14:42.145522+00:00 hydra1 kernel: do_idle+0xb6/0xf0
2026-05-20T22:14:42.145524+00:00 hydra1 kernel: cpu_startup_entry+0x29/0x30
2026-05-20T22:14:42.145526+00:00 hydra1 kernel: start_secondary+0x125/0x180
2026-05-20T22:14:42.145528+00:00 hydra1 kernel: ? soft_restart_cpu+0x14/0x14
2026-05-20T22:14:42.145529+00:00 hydra1 kernel: common_startup_64+0x13e/0x141
2026-05-20T22:14:42.145531+00:00 hydra1 kernel: </TASK>
2026-05-20T22:14:42.145532+00:00 hydra1 kernel: ---[ end trace 0000000000000000 ]---
From hydra2:
2026-05-20T22:14:47.565592+00:00 hydra2 kernel: ------------[ cut here ]------------
2026-05-20T22:14:47.565616+00:00 hydra2 kernel: Voluntary context switch within RCU read-side critical section!
2026-05-20T22:14:47.565619+00:00 hydra2 kernel: WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x238/0x2a0, CPU#10: swapper/10/0
2026-05-20T22:14:47.565622+00:00 hydra2 kernel: Modules linked in: nft_masq nft_chain_nat vxlan ip6_udp_tunnel udp_tunnel dummy bridge stp llc zfs(PO) spl(O) ebtable_filter ebtables ip6table_raw ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables nf_tables vhost_vsock vmw_vsock_virtio_transport_common vhost vhost_iotlb vsock qrtr nova_core cfg80211 binfmt_misc ee1004 intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm think_lmi rtsx_usb_ms irqbypass rapl intel_cstate firmware_attributes_class wmi_bmof snd_hda_codec_alc662 i2c_i801 snd_hda_codec_realtek_lib intel_wmi_thunderbolt mei_me i2c_smbus snd_hda_codec_nvhdmi nls_iso8859_1 memstick lpc_ich i2c_mux intel_pch_thermal snd_hda_codec_generic mei snd_hda_codec_hdmi nouveau gpu_sched drm_gpuvm snd_hda_intel mxm_wmi snd_hda_codec drm_ttm_helper ttm snd_hda_core snd_intel_dspcfg
2026-05-20T22:14:47.565627+00:00 hydra2 kernel: drm_exec snd_intel_sdw_acpi drm_display_helper snd_hwdep snd_pcm cec rc_core snd_timer i2c_algo_bit snd video soundcore mac_hid sch_fq_codel rbd libceph krb5enc authenc camellia_generic camellia_aesni_avx2 camellia_aesni_avx_x86_64 camellia_x86_64 cmac krb5 dm_crypt dm_multipath efi_pstore nfnetlink uas usb_storage ghash_clmulni_intel e1000e pata_acpi wmi ahci libahci rtsx_usb_sdmmc rtsx_usb dm_mirror dm_region_hash dm_log msr dmi_sysfs autofs4 aesni_intel
2026-05-20T22:14:47.565631+00:00 hydra2 kernel: CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: P O 7.0.0-15-generic #15-Ubuntu PREEMPT(lazy)
2026-05-20T22:14:47.565634+00:00 hydra2 kernel: Tainted: [P]=PROPRIETARY_MODULE, [O]=OOT_MODULE
2026-05-20T22:14:47.565636+00:00 hydra2 kernel: Hardware name: LENOVO 30B4S16S00/102F, BIOS S00KT73A 05/24/2022
2026-05-20T22:14:47.565638+00:00 hydra2 kernel: RIP: 0010:rcu_note_context_switch+0x238/0x2a0
2026-05-20T22:14:47.565640+00:00 hydra2 kernel: Code: 88 09 00 00 48 8d 93 88 09 00 00 48 39 d1 75 6a 48 23 47 20 74 4d 4c 89 e6 e8 64 f3 ff ff e9 46 fe ff ff 48 8d 3d 28 07 9a 02 <67> 48 0f b9 3a e9 02 fe ff ff 49 8b 7c 24 20 48 89 7d e0 e8 e0 bf
2026-05-20T22:14:47.565670+00:00 hydra2 kernel: RSP: 0018:ffffce060018fe40 EFLAGS: 00010002
2026-05-20T22:14:47.565673+00:00 hydra2 kernel: RAX: 0000000000000001 RBX: ffff8ae5c0e32a80 RCX: 0000000000000000
2026-05-20T22:14:47.565675+00:00 hydra2 kernel: RDX: 0000000000000000 RSI: ffffffff87120c32 RDI: ffffffff888df740
2026-05-20T22:14:47.565677+00:00 hydra2 kernel: RBP: ffffce060018fe60 R08: 0000000000000000 R09: 0000000000000000
2026-05-20T22:14:47.565680+00:00 hydra2 kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffff8af53fd34540
2026-05-20T22:14:47.565682+00:00 hydra2 kernel: R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
2026-05-20T22:14:47.565683+00:00 hydra2 kernel: FS: 0000000000000000(0000) GS:ffff8af5b6f00000(0000) knlGS:0000000000000000
2026-05-20T22:14:47.565686+00:00 hydra2 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2026-05-20T22:14:47.565688+00:00 hydra2 kernel: CR2: 0000647ec6ba5000 CR3: 0000000eb9444004 CR4: 00000000003726f0
2026-05-20T22:14:47.565690+00:00 hydra2 kernel: Call Trace:
2026-05-20T22:14:47.565692+00:00 hydra2 kernel: <TASK>
2026-05-20T22:14:47.565694+00:00 hydra2 kernel: __schedule+0xcf/0x630
2026-05-20T22:14:47.565697+00:00 hydra2 kernel: schedule_idle+0x22/0x40
2026-05-20T22:14:47.565699+00:00 hydra2 kernel: do_idle+0xb6/0xf0
2026-05-20T22:14:47.565700+00:00 hydra2 kernel: cpu_startup_entry+0x29/0x30
2026-05-20T22:14:47.565702+00:00 hydra2 kernel: start_secondary+0x125/0x180
2026-05-20T22:14:47.565704+00:00 hydra2 kernel: ? soft_restart_cpu+0x14/0x14
2026-05-20T22:14:47.565706+00:00 hydra2 kernel: common_startup_64+0x13e/0x141
2026-05-20T22:14:47.565707+00:00 hydra2 kernel: </TASK>
2026-05-20T22:14:47.565709+00:00 hydra2 kernel: ---[ end trace 0000000000000000 ]---
And hydra3:
2026-05-20T21:54:56.379185+00:00 hydra3 kernel: ------------[ cut here ]------------
2026-05-20T21:54:56.379206+00:00 hydra3 kernel: Voluntary context switch within RCU read-side critical section!
2026-05-20T21:54:56.379207+00:00 hydra3 kernel: WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch+0x238/0x2a0, CPU#0: swapper/0/0
2026-05-20T21:54:56.379209+00:00 hydra3 kernel: Modules linked in: vhost_net tap nft_masq nft_chain_nat vxlan ip6_udp_tunnel udp_tunnel dummy bridge stp llc zfs(PO) spl(O) ebtable_filter ebtables ip6table_raw ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter ip_tables x_tables nf_tables vhost_vsock vmw_vsock_virtio_transport_common vhost vhost_iotlb vsock qrtr nova_core cfg80211 binfmt_misc intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_alc662 snd_hda_codec_realtek_lib ee1004 snd_hda_codec_generic snd_hda_codec_nvhdmi nouveau kvm snd_hda_codec_hdmi gpu_sched irqbypass drm_gpuvm drm_ttm_helper rapl snd_hda_intel ttm snd_hda_codec intel_wmi_thunderbolt snd_hda_core intel_cstate drm_exec snd_intel_dspcfg think_lmi rtsx_usb_ms drm_display_helper snd_intel_sdw_acpi firmware_attributes_class wmi_bmof mxm_wmi snd_hwdep memstick cec
2026-05-20T21:54:56.379213+00:00 hydra3 kernel: i2c_i801 snd_pcm mei_me i2c_smbus rc_core intel_pch_thermal i2c_mux snd_timer i2c_algo_bit snd mei lpc_ich video soundcore input_leds joydev mac_hid sch_fq_codel rbd libceph krb5enc authenc camellia_generic camellia_aesni_avx2 camellia_aesni_avx_x86_64 camellia_x86_64 cmac krb5 dm_crypt efi_pstore dm_multipath nfnetlink hid_generic usbhid hid ghash_clmulni_intel nvme nvme_core nvme_keyring nvme_auth hkdf e1000e ahci libahci pata_acpi wmi rtsx_usb_sdmmc rtsx_usb dm_mirror dm_region_hash dm_log msr dmi_sysfs autofs4 aesni_intel
2026-05-20T21:54:56.379215+00:00 hydra3 kernel: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: P O 7.0.0-15-generic #15-Ubuntu PREEMPT(lazy)
2026-05-20T21:54:56.379216+00:00 hydra3 kernel: Tainted: [P]=PROPRIETARY_MODULE, [O]=OOT_MODULE
2026-05-20T21:54:56.379218+00:00 hydra3 kernel: Hardware name: LENOVO 30B4S23S00/102F, BIOS S00KT73A 05/24/2022
2026-05-20T21:54:56.379219+00:00 hydra3 kernel: RIP: 0010:rcu_note_context_switch+0x238/0x2a0
2026-05-20T21:54:56.379243+00:00 hydra3 kernel: Code: 88 09 00 00 48 8d 93 88 09 00 00 48 39 d1 75 6a 48 23 47 20 74 4d 4c 89 e6 e8 64 f3 ff ff e9 46 fe ff ff 48 8d 3d 28 07 9a 02 <67> 48 0f b9 3a e9 02 fe ff ff 49 8b 7c 24 20 48 89 7d e0 e8 e0 bf
2026-05-20T21:54:56.379245+00:00 hydra3 kernel: RSP: 0018:ffffffff86403dd0 EFLAGS: 00010002
2026-05-20T21:54:56.379246+00:00 hydra3 kernel: RAX: 0000000000000001 RBX: ffffffff864134c0 RCX: 0000000000000000
2026-05-20T21:54:56.379247+00:00 hydra3 kernel: RDX: 0000000000000000 RSI: ffffffff85120c32 RDI: ffffffff868df740
2026-05-20T21:54:56.379249+00:00 hydra3 kernel: RBP: ffffffff86403df0 R08: 0000000000000000 R09: 0000000000000000
2026-05-20T21:54:56.379251+00:00 hydra3 kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffff8e9bff834540
2026-05-20T21:54:56.379252+00:00 hydra3 kernel: R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
2026-05-20T21:54:56.379253+00:00 hydra3 kernel: FS: 0000000000000000(0000) GS:ffff8e9c78a00000(0000) knlGS:0000000000000000
2026-05-20T21:54:56.379254+00:00 hydra3 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2026-05-20T21:54:56.379256+00:00 hydra3 kernel: CR2: 00007590cac35000 CR3: 000000040b244005 CR4: 00000000003726f0
2026-05-20T21:54:56.379257+00:00 hydra3 kernel: Call Trace:
2026-05-20T21:54:56.379258+00:00 hydra3 kernel: <TASK>
2026-05-20T21:54:56.379260+00:00 hydra3 kernel: __schedule+0xcf/0x630
2026-05-20T21:54:56.379261+00:00 hydra3 kernel: schedule_idle+0x22/0x40
2026-05-20T21:54:56.379262+00:00 hydra3 kernel: do_idle+0xb6/0xf0
2026-05-20T21:54:56.379263+00:00 hydra3 kernel: cpu_startup_entry+0x29/0x30
2026-05-20T21:54:56.379264+00:00 hydra3 kernel: rest_init+0xef/0xf0
2026-05-20T21:54:56.379265+00:00 hydra3 kernel: start_kernel+0x4b4/0x4c0
2026-05-20T21:54:56.379267+00:00 hydra3 kernel: x86_64_start_reservations+0x24/0x30
2026-05-20T21:54:56.379268+00:00 hydra3 kernel: x86_64_start_kernel+0x134/0x140
2026-05-20T21:54:56.379269+00:00 hydra3 kernel: common_startup_64+0x13e/0x141
2026-05-20T21:54:56.379270+00:00 hydra3 kernel: </TASK>
2026-05-20T21:54:56.379271+00:00 hydra3 kernel: ---[ end trace 0000000000000000 ]---
I think one thing I can do is dump the Ubuntu Fan and try Micro OVN instead – however, with only a single gigabit network adapter (and the complexity) I was trying to stay away from it. The other option is to just move back to 24.04 and 5.21/stable where this configuration was pretty stable. (I acquired the 3rd host to use Ceph with LXD; to confirm some software handles it correctly and doesn’t try to move disks around. Plus it seems rather interesting!)
Thanks!
