KO After update 2.0.38 to 2.1.18 - On zone Lx - ZFS

filesystem ZFS
zone LX with ubuntu LTS 16.06

before the update to the lastest stable version it’s ok with 2.0.38 after
timeout on webpage and process urbackupsrv dies

installation with PPA: http://launchpad.net/~uroni/+archive/urbackup

Install via e.g.

sudo add-apt-repository ppa:uroni/urbackup
sudo apt update
sudo apt install urbackup-server

any ideas?

This is a snippet of the strace command:

setgroups(0, [])                        = 0
setgid(112)                             = 0
setuid(108)                             = 0
mmap(NULL, 10489856, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_STACK, -1, 0) = 0x7ffff2600000
mprotect(0x7ffff2600000, 4096, PROT_NONE) = 0
clone(child_stack=0x7ffff2ffffb0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7ffff30009d0, tls=0x7ffff3000700, child_tidptr=0x7ffff30009d0) = 68586
open("urbackup/server_ident.key", O_RDONLY) = 5
urbackupsrv: urbackupcommon/os_functions_lin.cpp:1096: void assert_process_priority(): Assertion `io_prio == (4 | IOPRIO_CLASS_BE<<IOPRIO_CLASS_SHIFT) || io_prio== (4 | IOPRIO_CLASS_NONE<<IOPRIO_CLASS_SHIFT)' failed.
lseek(5, 0, SEEK_END)                   = 23
lseek(5, 0, SEEK_CUR <unfinished ...>
+++ killed by SIGABRT (core dumped) +++
Aborted (core dumped)

Cannot reproduce it (must be something kernel specific), but I accidentally left in the assertions. Sorry, will be removed with the next release (2.1.19).

thank you

Ok with 2.1.19