NSS_OPTIONS

Sometimes developers put undocumented options in their code to help with debugging issues. This morning I came across one of such options which prints extra debug information when executing NSS queries.

First you need to disable nscd:

# svcadm disable -t name-service/cache

Then you need to set env variable debug_eng_loop to >0, for example:

# NSS_OPTIONS="debug_eng_loop=2" ping -I 1 wp.pl
NSS_retry(0): 'ipnodes': trying 'files' ... result=NOTFOUND, action=CONTINUE
NSS: 'ipnodes': continue ...
NSS_retry(0): 'ipnodes': trying 'dns' ... result=SUCCESS, action=RETURN
NSS: 'ipnodes': return.
PING wp.pl: 56 data bytes

What's good about it is that it tells you which database configured in NSS returned the result.

Setting RPATH

Today I was made aware that elfedit tool in Solaris 11 allows for setting RPATH (among other things). The only caveat is that a binary had to be linked on Solaris 11. It is very easy to use:

 # elfedit -e 'dyn:runpath $ORIGIN/../lib' /opt/bin/myprog 

There is a nice blog entry about it from Ali Bahrami.

Btrfs: "are we there yet?"

Not in the foreseeable future...