Re: ZFS: time to drop Big Scary Warning

[Andreas Gustafsson <gson%gson.org@localhost>]

Greg Troxel wrote:
> > That's a good test, but how does zfs compare in for the same test with lets
> > say ffs or ext2fs (filesystems that offer persistence)?
> 
> With the same system, booted in the  same way, but with 3 different
> filesystems mounted on /tmp, I get similar numbers of failures:
> 
> tmpfs	12
> ffs2	13
> zfs	18
> 
> So tmpfs/ffs2 are ~equal and zfs has a few more failures (but it all
> looks a bit random and non-repeatable).    So it's hard to sort out "zfs
> is buggy" vs "some tests fail in timing-related hard-to-understand ways
> and that seems provoked slightly more with /tmp on zfs".

Since I'm all too familiar with the randomly failing tests in the
NetBSD test suite, let me sort them out for you.  Of the test cases in
the zfs run that didn't match the releng results, these two are known
random failures reported in PR 55770:

>       ./usr.bin/cc/t_tsan_data_race:data_race_pie
>       ./usr.bin/c++/t_tsan_data_race:data_race_pie

This is probably the known random failure reported in PR 55692:

>       ./fs/nfs/t_rquotad:get_nfs_be_1_group

This failure is already reported in PR 55603, though your report is
the first of it failing on real hardware:

>       ./modules/t_x86_pte:svs_g_bit_set

This one is reported as randomly failing in PR 55331, but since that
problem appears to be tmpfs related, it may be the case that tmpfs and
zfs are both buggy:

>       ./lib/libarchive/t_libarchive:libarchive

The remaining four failed test cases are _not_ known to fail randomly,
and as far as I know, do not have existing PRs.  Since they all
involve file system operations, it seems likely that they are in fact
zfs related in some way:

>       ./bin/cp/t_cp:file_to_file
>       ./lib/libc/stdlib/t_mktemp:mktemp_large_template
>       ./lib/libc/sys/t_stat:stat_chflags
>       ./usr.bin/ztest/t_ztest:assert

-- 
Andreas Gustafsson, gson%gson.org@localhost