1. Prepare enviroment with just single ost. (single node will also do)
2. lfs setstripe -C 2000 /mnt/lustre/file0
<Hang>

06:23:00 centos79 kernel: Lustre: mdt00_001: service thread pid 2247 was inactive for 40.028 seconds. The thread might be hung, or it might only be slow and will resume later. Dumping the stack trace for debugging purposes:
06:23:00 centos79 kernel: Pid: 2247, comm: mdt00_001 3.10.0-1160.15.2.el7.x86_64 #1 SMP Wed Feb 3 15:06:38 UTC 2021
06:23:00 centos79 kernel: Call Trace:
06:23:00 centos79 kernel: [<0>] osp_precreate_reserve+0x490/0x9b0 [osp]
06:23:00 centos79 kernel: [<0>] osp_declare_create+0x1ac/0x660 [osp]
06:23:00 centos79 kernel: [<0>] lod_sub_declare_create+0xdf/0x210 [lod]
06:23:00 centos79 kernel: [<0>] lod_qos_declare_object_on+0xf3/0x420 [lod]
06:23:00 centos79 kernel: [<0>] lod_ost_alloc_rr.constprop.23+0xaad/0x1150 [lod]
06:23:00 centos79 kernel: [<0>] lod_qos_prep_create+0x1245/0x1a20 [lod]
06:23:00 centos79 kernel: [<0>] lod_prepare_create+0x230/0x320 [lod]
06:23:00 centos79 kernel: [<0>] lod_declare_striped_create+0x1fe/0x9e0 [lod]
06:23:00 centos79 kernel: [<0>] lod_declare_xattr_set+0x139/0x2020 [lod]
06:23:00 centos79 kernel: [<0>] mdd_create_data+0x532/0x760 [mdd]
06:23:00 centos79 kernel: [<0>] mdt_mfd_open+0xcb7/0xed0 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_finish_open+0x79b/0x930 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_open_by_fid_lock+0x704/0xb10 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_reint_open+0x783/0x2a80 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_reint_rec+0x8a/0x240 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_reint_internal+0x76c/0xb50 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_intent_open+0x93/0x480 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_intent_opc+0x1e0/0xc10 [mdt]
06:23:00 centos79 kernel: [<0>] mdt_intent_policy+0x1a1/0x360 [mdt]
06:23:00 centos79 kernel: [<0>] ldlm_lock_enqueue+0x3c5/0xb50 [ptlrpc]
06:23:00 centos79 kernel: [<0>] ldlm_handle_enqueue0+0xab6/0x16d0 [ptlrpc]
06:23:00 centos79 kernel: [<0>] tgt_enqueue+0x64/0x240 [ptlrpc]
06:23:00 centos79 kernel: [<0>] tgt_request_handle+0x823/0x1850 [ptlrpc]
06:23:00 centos79 kernel: [<0>] ptlrpc_server_handle_request+0x253/0xb10 [ptlrpc]
06:23:00 centos79 kernel: [<0>] ptlrpc_main+0xbf4/0x15e0 [ptlrpc]
06:23:00 centos79 kernel: [<0>] kthread+0xd1/0xe0
06:23:00 centos79 kernel: [<0>] ret_from_fork_nospec_begin+0xe/0x21
06:23:00 centos79 kernel: [<0>] 0xfffffffffffffffe