freebsd-skq/contrib/amd/BUGS

	    LIST OF KNOWN BUGS IN AM-UTILS OR OPERATING SYSTEMS


(1) mips-sgi-irix*

[1A] known to have flaky NFS V.3 and TCP.  Amd tends to hang or spin
infinitely after a few hours or days of use.  Users must install recommended
patches from vendor.  Patches help, but not all the time.  Otherwise avoid
using NFS V.3 and TCP on these systems, by setting

	/defaults opts:=vers=2,proto=udp

[1B] yp_all() leaks a file descriptor.  Eventually amd runs out of file
descriptors and hangs.  Am-utils circumvents this by using its own version
of yp_all which uses udp and iterates over NIS maps.  The latter isn't as
reliable as yp_all() which uses TCP, but it is better than hanging.

(I have some reports that older version of hpux-9, with older libc, also
leak file descriptors.)

[1C] SGI's MIPSpro C compiler on IRIX 6 has the unfortunate habit of
creating code specificially for the machine it runs on.  The ABI and ISA
used depend very much on the OS version and compiler release used.  This
means that the resulting amd binary won't run on machines different from
the build host, particularly older ones.  Older versions of am-utils
enforced the O32 ABI when compiling with cc to work around this, but this
ABI is deprecated in favor of the N32 ABI now, so we use -n32 -mips3 to
ensure that the binaries run on every host capable of running IRIX 6 at
all.  If this is not appropriate for you, configure with something like
CC='cc -64' instead to get the desired ABI and ISA.

(2) alpha-unknown-linux-gnu (RedHat Linux 4.2)

hasmntopt(mnt, opt) can go into an infinite loop if opt is any substring
of mnt->mnt_opts.  Redhat 5.0 does not have this libc bug.  Here is an
example program:

#include <stdio.h>
#include <mntent.h>
main()
{
  struct mntent mnt;
  char *cp;
  mnt.mnt_opts = "intr,rw,port=1023,timeo=8,foo=br,retrans=110,indirect,map=/usr/local/AMD/etc/amd.proj,boo";
  cp = hasmntopt(&mnt, "ro");
  printf("cp = %s\n", cp);
  exit(0);
}

It is possible that sufficiently newer version of libc for RH4.2 fix this
problem.


(3) mips-dec-ultrix4.3

Rainer Orth <ro@TechFak.Uni-Bielefeld.DE> reports

[3A] One needs the Kernel Config Files (UDTBIN430) subset installed to
compile am-utils, otherwise essential header files (net/if.h, net/route.h,
rpcsvc/mount.h, rpcsvc/yp_prot.h, rpcsvc/ypclnt.h, sys/proc.h) are
missing.

[3B] It's probably impossible to build am-utils with DEC C on Ultrix V4.3.
This compiler is pseudo-ANSI only.  Maybe the new ANSI C compiler in V4.3A
and beyond will do.  I successfully used gcc 2.8.1.

[3C] You need to build against a recent libhesiod (I used 3.0.2) and
libresolv/lib44bsd (I used BIND 4.9.5-P1).  The resolver routines in
libc seem to cause random memory corruption.  It is necessary to specify
LIBS=-l44bsd.  lib44bsd is a helper library of libresolv used to supply
functions like strdup which are missing on the host system.  This isn't
currently autoconfiscated.

[3D] You need to configure with CONFIG_SHELL=/bin/sh5 /bin/sh5 buildall;
/bin/sh cannot handle the shell functions used in buildall and is both
buggy and slow.

[3E] At least the gcc 2.7.0 fixincludes-mangled <sys/utsname.h> needs a
forward declaration of struct utsname to avoid lots of gcc warnings:

RCS file: RCS/utsname.h,v
retrieving revision 1.1
diff -u -r1.1 utsname.h
--- utsname.h   1995/06/19 13:07:01     1.1
+++ utsname.h   1998/01/27 12:34:26
@@ -59,6 +59,7 @@
 #ifdef KERNEL
 #include "../h/limits.h"
 #else /* user mode */
+struct utsname;
 extern int     uname _PARAMS((struct utsname *));
 #endif
 #define __SYS_NMLN 32


(4) powerpc-ibm-aix4.2.1.0

[4A] "Randall S. Winchester" <rsw@Glue.umd.edu> reports that for amd to
start, you need to kill and restart rpc.mountd and possibly also make sure
that nfsd is running.  Normally these are not required.

[4B] "Stefan Vogel" <vogel@physik.unizh.ch> reports that if your amq
executable dump core unexpectedly, then it may be a bug in gcc 2.7.x.
Upgrade to gcc 2.8.x or use IBM's xlC compiler.

[C] Do not link amd with libnsl.  It is buggy and causes amd to core dump
in strlen inside strdup inside svc_register().


(5) *-linux-rh51 (RedHat Linux 5.1)

There's a UDP file descriptor leak in libnsl in RedHat Linux 5.1.  This
library part of glibc2.  Am-utils currently declares redhat 5.1 systems as
having a "broken yp_all" and using an internal, slower, leak-free version.
The leak is known to the glibc maintainers and a fix from them is due soon,
but it is not yet in the glibc-2.0.7-19 RPM.


(6) rs6000-ibm-aix4.1.x

A bug in libc results in an amq binary that doesn't work; amq -v dumps core
in xdr_string.  There is no known fix (source code or vendor patch) at this
time.  (Please let amd-dev know if you know of a fix.)


(7) *-aix4.3.2.0

The plock() function will pre-reserve all of the memory up to the maximum
listed in the ulimit.  If the ulimit is infinite, plock() will try to take
all of the system's memory, and fail with ENOMEM (Not Enough Space).
Normally ulimit may be set to a few gigs of max memory usage, but even that
is too much; Amd doesn't need more than a few megs of resident memory size
(depending on the particular usage, number of maps, etc.)  Solution: lower
your ulimit before starting amd.  This can be done inside the ctl-amd
script, but be careful not to limit it too low.  Alternatively, don't use
plock on aix-4.3: set it to plock=no in amd.conf (which is the default if
you do nothing).


(8) *-linux (systems using glibc 2.1, such as RedHat-6.x)

There's a UDP file descriptor leak in the NIS routines in glibc, especially
those that do yp_bind.  Until this is bug fixed, do not set nis_domain in
amd.conf, but let the system pick up the default domain name as set by your
system.  That would avoid using the buggy yp_bind routines in libc.


(9) *-linux (SuSE systems using unfsd)

The user-level nfsd (2.2beta44) on older SuSE Linux systems (and possibly
others) dies with a SEGV when amd tries to contact it for access to a volume
that does not exist, or one for which there is no permission to mount.


(10) *-*-hpux11

If you're using NFSv3, you must install HP patches PHNE_20344 and
PHNE_20371.  If you don't, and you try to use amd with NFSv3 over TCP, your
kernel will panic.


(11) *-linux* (any system using a 2.2.18+ kernel)

The Linux kernels don't support Amd's direct mounts very well, leading to
erratic behavior: shares that don't get remounted after the first timeout,
inability to restart Amd because its mount points cannot be unmounted,
etc. There are some kernel patches on the am-utils Web site, which solve
these problems.  See http://www.am-utils.org/patches/.

UPDATE: kernels 2.4.10 and later completely disallow the direct mount hack,
so direct mounts are simply not possible on those Linux kernels.

(12) *-aix5.1.0.0 and *-hpux9*

/bin/sh is broken and fails to run the configure script properly. You need
to use /bin/ksh instead. The buildall script will do it for you; if for some
reason you need to run configure directly, run it using 'ksh configure'
instead of just 'configure'.

[12A] *-aix5.1.*

Apparently there is an NFS client side bug in vmount() which causes amd to
hang when it starts (and tries to NFS-mount itself).  According to IBM
engineers, this has to do with partial support code for IPv6: the NFS kernel
code doesn't appear to recognize the sin_family of the amd vmount(),
although amd does the right thing.  The bug appears to have been fixed in
AIX 5.2.  No known fix/patch is available for AIX 5.1 as of now (1/25/2003).

(13) *-linux and *-darwin6.0

Certain linux kernels (2.4.18+ are fine, 2.4.10- are probably bad, those in
between have not been tested) have a bug which causes them to reconnect
broken NFS/TCP connections using unprivileged ports (greater than 1024),
unlike the initial connections which do originate from privileged
ports.  This can upset quite a few NFS servers and causes accesses to the
mounted shares to fail with "Operation not permitted" (EPERM).

The darwin (MacOS X) kernel defaults to using unprivileged ports, but that
can be changed by setting the resvport mount flag (which amd sets by
default).  Nonetheless, if a TCP connection breaks, under certain unclear
circumstances the kernel might "forget" about that flag and start using
unprivileged ports, causing the same EPERM error above.


Erez & Ion.