[MooseFS-Users] Append operator not working on FreeBSD 10.3+

[Marin B. <li...@ol...>]

Hi,

I've just installed the MooseFS client (3.0.81) on a brand new FreeBSD 11.0 workstation. It runs fine except with the append operator (>>) which is not working as expected. More precisely, it produces the same effect as the output redirection operator (>), and overwrites the whole file instead of appending data to it.

$ uname -a
FreeBSD nb-00 11.0-RELEASE-p1 FreeBSD 11.0-RELEASE-p1 #0 r306420: Thu Sep 29 01:43:23 UTC 2016     ro...@re...:/usr/obj/usr/src/sys/GENERIC  amd64

Basic appending on a local volume (ZFS):


$ echo test1 > testfile.txt
$ cat testfile.txt
test1

$ echo test2 >> testfile.txt
$ cat testfile.txt
test1
test2

Now the same ops on MFS:


$ echo test1 > /mfs/testfile.txt
$ cat /mfs/testfile.txt
test1

$ echo test2 >> /mfs/testfile.txt
$ cat /mfs/testfile.txt
test2

I ran the same tests on an up-to-date FreeBSD 10.3 server and got the same results, so this is probably not new unless it is related to an update in the FUSE implementation.

I thought it might be a caching issue, but it seems it's not: the file still has the same contents even after I unmounted/remounted MFS.

I find this very alarming as it seems to be related to the way the MooseFS client is dealing with POSIX primitives. Should I worry ? Does anybody have an idea about why this is happening ?

Thanks!

Marin.