Converter

The converter serves two purposes: For Group Balancer and GEO Balancer it is used to rewrite files with to a new location. For the LRU policy converter is used to rewrite a file with a new layout e.g. rewrite a file with 2 replica into a RAID-6 like RAIN layout with the benefit of space savings. Internally the converter uses the XRootD third party copy mechanism and consumes one thread in the MGM for each running conversion transfer.

Configuration

The Converter is enabled/disabled by space:

# enable
eos space config default space.converter=on
# disable
eos space config default space.converter=off

The current status of the Converter can be seen via:

eos -b space status default
# ------------------------------------------------------------------------------------
# Space Variables
# ....................................................................................
...
converter                       := off
converter.ntx                   := 0
...

The number of concurrent transfers to run is defined via the converter.ntx space variable:

# schedule 10 transfers in parallel
eos space config default space.converter.ntx=10

One can see the same settings and the number of active conversion transfers (scroll to the right):

eos space ls
#------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
#     type #           name #  groupsize #   groupmod #N(fs) #N(fs-rw) #sum(usedbytes) #sum(capacity) #capacity(rw) #nom.capacity #quota #balancing # threshold # converter #  ntx # active #intergroup
#------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
spaceview           default           22           22    202       123          2.91 T       339.38 T      245.53 T          0.00     on        off        0.00          on 100.00     0.00         off

Log Files

The Converter has a dedicated log file under /var/log/eos/mgm/Converter.log which shows scheduled conversions and errors of conversion jobs. To get more verbose information you can change the log level:

# switch to debug log level on the MGM
eos debug debug

# switch back to info log level on the MGM
eos debug info