LU-1189 tests: run save_lustre_params() on facets

This patch fixes save_lustre_params() and restore_lustre_params()
to get and set Lustre parameters through do_facet() instead of
do_node(). This will fix the issue that restore_lustre_params() still
tries to restore the saved params on the original node which will
likely become inactive under failover test environment.

Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes \
clientcount=4 osscount=2 mdscount=2 austeroptions=-R \
failover=true useiscsi=true \
testlist=replay-vbr,replay-dual

Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: I5bfc4797727aaaa15fac1e34b6a7182ae8f26da8
Reviewed-on: http://review.whamcloud.com/5628
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Li Wei <wei.g.li@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Wei Liu <wei3.liu@intel.com>
LU-3142 mdt: update mdt_max_mdsize in mdt_lvbo_size

during calling mdt_lvbo_size to get the size of lsm, mdt_max_mdsize
could be less than the lsm size of this object in failover mode.
then it is needed to check and update this value.

Test-Parameters: envdefinitions=RECOVERY_MDS_SCALE_EXCEPT=failover_ost \
clientdistro=el6 serverdistro=el6 clientarch=x86_64 serverarch=x86_64 \
clientcount=4 osscount=2 mdscount=2 austeroptions=-R failover=true \
useiscsi=true testlist=recovery-mds-scale

Change-Id: Id490c346ca9f34edcc963334e396678f1b41562c
Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Signed-off-by: Jian Yu <jian.yu@intel.com>
Reviewed-on: http://review.whamcloud.com/6102
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>