# DRBD assertion errors and LINSTOR resources stuck in DELETING on Proxmox 9 / ZFS-Thin **URL:** \ **Category:** DRBD\ **Tags:** drbd\ **Created:** [July 10, 2026, 2:07pm UTC](https://forums.linbit.com/t/drbd-assertion-errors-and-linstor-resources-stuck-in-deleting-on-proxmox-9-zfs-thin/1246 "2026-07-10T14:07:32Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jakub.novak](https://avatars.discourse-cdn.com/v4/letter/j/e68b1a/32.png) [@jakub.novak](https://forums.linbit.com/u/jakub.novak)\ **Post date:** [July 10, 2026, 2:07pm UTC](https://forums.linbit.com/t/drbd-assertion-errors-and-linstor-resources-stuck-in-deleting-on-proxmox-9-zfs-thin/1246/1 "2026-07-10T14:07:32Z")
Hello, I am running a three-node Proxmox cluster with LINSTOR, DRBD, and ZFS-Thin storage. All three nodes are fresh installations with identical hardware and software. All packages were updated from the currently configured repositories. Two of the three nodes repeatedly produce DRBD assertion errors in `dmesg`, while the third node does not show these errors. I have not been able to find any relevant difference between the nodes. Example errors: ```auto [91064.078391] drbd pm-6f25d6aa/0 drbd1007: ASSERTION atomic_read(&device->local_cnt) > 0 FAILED in drbd_al_begin_io_fastpath [91064.078477] drbd pm-6f25d6aa/0 drbd1007: ASSERTION i >= 0 FAILED in put_ldev [91064.082281] drbd pm-6f25d6aa/0 drbd1007: ASSERTION i >= 0 FAILED in put_ldev [91064.093978] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91064.093990] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91064.093995] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91064.193423] drbd pm-6f25d6aa/0 drbd1007: ASSERTION i >= 0 FAILED in put_ldev [91064.193461] drbd pm-6f25d6aa/0 drbd1007: ASSERTION i >= 0 FAILED in put_ldev [91064.194516] drbd pm-dfb4f624/0 drbd1001: ASSERTION atomic_read(&device->local_cnt) > 0 FAILED in drbd_al_begin_io_fastpath [91064.194567] drbd pm-dfb4f624/0 drbd1001: ASSERTION i >= 0 FAILED in put_ldev [91064.194996] drbd pm-dfb4f624/0 drbd1001: ASSERTION i >= 0 FAILED in put_ldev [91064.304528] drbd pm-dfb4f624/0 drbd1001: ASSERTION i >= 0 FAILED in put_ldev [91064.304541] drbd pm-dfb4f624/0 drbd1001: ASSERTION i >= 0 FAILED in put_ldev [91065.375341] drbd pm-437e50b0/0 drbd1008: ASSERTION atomic_read(&device->local_cnt) > 0 FAILED in drbd_al_begin_io_fastpath [91065.375357] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91065.377937] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91065.787224] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91065.787232] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev [91065.787235] drbd pm-437e50b0/0 drbd1008: ASSERTION i >= 0 FAILED in put_ldev ``` I am also seeing resources become stuck in the `DELETING` state after attempting to delete them: ```auto │ pm-f82a68ca │ px-hq-core01 │ DRBD,STORAGE │ │ Ok │ DELETING │ Yes │ │ pm-f82a68ca │ px-hq-core02 │ DRBD,STORAGE │ │ Ok │ DELETING │ Yes │ │ pm-f82a68ca │ px-hq-core03 │ DRBD,STORAGE │ │ Ok │ DELETING │ Yes │ ``` The resource remains in this state on all three nodes and is not removed automatically. ## Versions from one affected node ```auto proxmox-ve: 9.2.0 pve-manager: 9.2.4 running kernel: 7.0.14-3-pve zfsutils-linux: 2.4.3-pve1 ``` ```auto Linux px-hq-core01 7.0.14-3-pve #1 SMP PREEMPT_DYNAMIC PMX 7.0.14-3 (2026-07-03T19:51Z) x86_64 GNU/Linux ``` DRBD kernel module: ```auto filename: /lib/modules/7.0.14-3-pve/updates/dkms/drbd.ko version: 9.3.3 vermagic: 7.0.14-3-pve SMP preempt mod_unload modversions ``` LINSTOR client: ```auto linstor-client 1.28.1; GIT-hash: UNKNOWN ``` ## Questions 1. What is the recommended procedure for removing resources that are stuck in the `DELETING` state? 2. How can I safely clean up the resource without leaving orphaned DRBD devices, ZFS datasets, or LINSTOR database entries? 3. What could cause these DRBD assertion failures? 4. Are the `drbd_al_begin_io_fastpath` and `put_ldev` assertion errors related to the stuck resource deletion? 5. Is this a known issue with DRBD 9.3.3, Proxmox kernel 7.0.14, LINSTOR, or the ZFS-Thin backend? 6. What additional logs or command outputs should I provide to troubleshoot this? The third node have the same hardware, installed packages, kernel, DRBD version, and LINSTOR configuration, but it does not produce the assertion errors. Any guidance would be appreciated. ---
**Author:** ![kermat](https://yyz1.discourse-cdn.com/flex003/user_avatar/forums.linbit.com/kermat/32/21_2.png) [@kermat](https://forums.linbit.com/u/kermat)\ **Post date:** [July 20, 2026, 3:43pm UTC](https://forums.linbit.com/t/drbd-assertion-errors-and-linstor-resources-stuck-in-deleting-on-proxmox-9-zfs-thin/1246/2 "2026-07-20T15:43:42Z")
> [@jakub.novak](#): > > 1. What is the recommended procedure for removing resources that are stuck in the `DELETING` state? > > 2. How can I safely clean up the resource without leaving orphaned DRBD devices, ZFS datasets, or LINSTOR database entries? I usually tear down the DRBD device using `drbdadm` or `drbdsetup`, then remove the backing volume (in your case the zvol using `zfs destroy`), and then try deleting the resource from LINSTOR to cleanup the LINSTOR database entries and DRBD configurations. > [@jakub.novak](#): > > 1. Are the `drbd_al_begin_io_fastpath` and `put_ldev` assertion errors related to the stuck resource deletion? > > 2. Is this a known issue with DRBD 9.3.3, Proxmox kernel 7.0.14, LINSTOR, or the ZFS-Thin backend? This isn’t an issue I’m familiar with, or one that I could find others talking about, but seems like like assertion could be related to the stuck resource deletion. > [@jakub.novak](#): > > 1. What additional logs or command outputs should I provide to troubleshoot this? I’m wondering what was happening immediately before the assertion errors cropped up, or what operations you were performing when the error was observed? Perhaps you can share some logs surrounding the assertion messages? Can you share some details about the backing volumes and trim settings? ```sh # ZFS backing geometry zfs get volblocksize,volmode,refreservation / zpool get ashift # DRBD discard-related options in effect drbdsetup show --show-defaults | grep -iE 'discard|al-|rs-discard' grep -riE 'discard|al-extents|rs-discard' /var/lib/linstor.d/*.res /etc/drbd.d/ 2>/dev/null # Is fstrim / discard active? systemctl status fstrim.timer; cat /etc/fstab | grep -i discard lsblk -D # DISC-GRAN / DISC-MAX columns down the stack ``` ---
**Author:** ![koen](https://yyz1.discourse-cdn.com/flex003/user_avatar/forums.linbit.com/koen/32/342_2.png) [@koen](https://forums.linbit.com/u/koen)\ **Post date:** [July 28, 2026, 9:09am UTC](https://forums.linbit.com/t/drbd-assertion-errors-and-linstor-resources-stuck-in-deleting-on-proxmox-9-zfs-thin/1246/3 "2026-07-28T09:09:17Z")
Hi, we have also noticed this behaviour. On proxmox 9.2.5 with the latest (right now 28-07-2026) drbd and linstor packages. We also use ZFS\_THIN. > [@kermat](#): > > > [@jakub.novak](#): > > > > 1. What is the recommended procedure for removing resources that are stuck in the `DELETING` state? > > > > 2. How can I safely clean up the resource without leaving orphaned DRBD devices, ZFS datasets, or LINSTOR database entries? > > I usually tear down the DRBD device using `drbdadm` or `drbdsetup`, then remove the backing volume (in your case the zvol using `zfs destroy`), and then try deleting the resource from LINSTOR to cleanup the LINSTOR database entries and DRBD configurations. The thing is, that the deletion cannot finish succesfully because ‘something’ is keeping the zvol busy: ```auto # zfs destroy pool1/pm-15b3d58f_00000 cannot destroy 'pool1/pm-15b3d58f_00000': dataset is busy ``` The result is that you have to reboot the physical node (move all payload from that node and then reboot it) before you can remove the zvol. Unfortunately that leaves the linstor resource in a ‘undefined’ state still, since the deletion process could not complete in one go. Perhaps linstor could be adjusted so that the deletion process (in case of ZFS thin) would time out after 5 seconds and then just let the zvol exist and/or put a message somewhere that it has to be removed by hand. That way your linstor resource keeps a sane state and the only thing you are left with is a ‘unused’ zvol. ---
**Author:** ![Dan](https://avatars.discourse-cdn.com/v4/letter/d/eada6e/32.png) [@Dan](https://forums.linbit.com/u/Dan)\ **Post date:** [August 3, 2026, 10:02am UTC](https://forums.linbit.com/t/drbd-assertion-errors-and-linstor-resources-stuck-in-deleting-on-proxmox-9-zfs-thin/1246/4 "2026-08-03T10:02:39Z")
Probably related to [ASSERTION i\>= 0 FAILED in put\_ldev · Issue #137 · LINBIT/drbd · GitHub](https://github.com/LINBIT/drbd/issues/137). Hopefully fixed with the next DRBD Release. Current best fix; Reboot affected Node. After that try to minimize parallel actions related to syncs.