diff --git a/SequenceAnalysis/src/org/labkey/sequenceanalysis/analysis/GLNexusHandler.java b/SequenceAnalysis/src/org/labkey/sequenceanalysis/analysis/GLNexusHandler.java
index 96a600b83..0864c7cfd 100644
--- a/SequenceAnalysis/src/org/labkey/sequenceanalysis/analysis/GLNexusHandler.java
+++ b/SequenceAnalysis/src/org/labkey/sequenceanalysis/analysis/GLNexusHandler.java
@@ -1,5 +1,9 @@
 package org.labkey.sequenceanalysis.analysis;
 
+import com.google.common.io.Files;
+import htsjdk.samtools.SAMSequenceDictionary;
+import htsjdk.samtools.SAMSequenceRecord;
+import htsjdk.variant.utils.SAMSequenceDictionaryExtractor;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.Logger;
@@ -12,6 +16,7 @@
 import org.labkey.api.sequenceanalysis.pipeline.AbstractParameterizedOutputHandler;
 import org.labkey.api.sequenceanalysis.pipeline.BcftoolsRunner;
 import org.labkey.api.sequenceanalysis.pipeline.PipelineOutputTracker;
+import org.labkey.api.sequenceanalysis.pipeline.ReferenceGenome;
 import org.labkey.api.sequenceanalysis.pipeline.SequenceAnalysisJobSupport;
 import org.labkey.api.sequenceanalysis.pipeline.SequenceOutputHandler;
 import org.labkey.api.sequenceanalysis.pipeline.SequencePipelineService;
@@ -159,9 +164,46 @@ else if (genomeIds.isEmpty())
                 throw new PipelineJobException("Missing configType");
             }
 
-            File outputVcf = new File(ctx.getOutputDir(), basename + ".vcf.gz");
+            // NOTE: due to strange bad_alloc errors, iterate the genome contig-by-contig for now:
+            List<File> vcfs = new ArrayList<>();
+            ReferenceGenome rg = ctx.getSequenceSupport().getCachedGenome(genomeId);
+            SAMSequenceDictionary dict = SAMSequenceDictionaryExtractor.extractDictionary(rg.getSequenceDictionary().toPath());
+            for (SAMSequenceRecord r : dict.getSequences())
+            {
+                File contigVcf = new File(ctx.getOutputDir(), basename + "." + r.getSequenceName() + ".vcf.gz");
+                File contigVcfIdx = new File(contigVcf.getPath() + ".tbi");
+                File doneFile = new File(contigVcf.getPath() + ".done");
+                ctx.getFileManager().addIntermediateFile(contigVcf);
+                ctx.getFileManager().addIntermediateFile(contigVcfIdx);
+                ctx.getFileManager().addIntermediateFile(doneFile);
+
+                if (doneFile.exists())
+                {
+                    if (!contigVcfIdx.exists())
+                    {
+                        throw new PipelineJobException("Missing index: " + contigVcf.getPath());
+                    }
+
+                    vcfs.add(contigVcf);
+                }
+                else
+                {
+                    ctx.getLogger().debug("Running GLNexus for contig: " + r.getSequenceName());
+                    new GLNexusWrapper(ctx.getLogger()).execute(inputVcfs, contigVcf, ctx.getFileManager(), binVersion, configType, r);
+                    vcfs.add(contigVcf);
+                    try
+                    {
+                        Files.touch(doneFile);
+                    }
+                    catch (IOException e)
+                    {
+                        throw new PipelineJobException(e);
+                    }
+                }
+            }
 
-            new GLNexusWrapper(ctx.getLogger()).execute(inputVcfs, outputVcf, ctx.getFileManager(), binVersion, configType);
+            File outputVcf = new File(ctx.getOutputDir(), basename + ".vcf.gz");
+            SequenceUtil.combineVcfs(vcfs, rg, outputVcf, ctx.getLogger(), true, null, true);
 
             ctx.getLogger().debug("adding sequence output: " + outputVcf.getPath());
             SequenceOutputFile so1 = new SequenceOutputFile();
@@ -217,7 +259,7 @@ private File ensureLocalCopy(File input, File workingDirectory, PipelineOutputTr
             }
         }
 
-        public void execute(List<File> inputGvcfs, File outputVcf, PipelineOutputTracker tracker, String binVersion, String configType) throws PipelineJobException
+        public void execute(List<File> inputGvcfs, File outputVcf, PipelineOutputTracker tracker, String binVersion, String configType, SAMSequenceRecord rec) throws PipelineJobException
         {
             File workDir = outputVcf.getParentFile();
             tracker.addIntermediateFile(outputVcf);
@@ -233,7 +275,10 @@ public void execute(List<File> inputGvcfs, File outputVcf, PipelineOutputTracker
             File localBashScript = new File(workDir, "docker.sh");
             tracker.addIntermediateFile(localBashScript);
 
-            try (PrintWriter writer = PrintWriters.getPrintWriter(localBashScript))
+            File bed = new File(workDir, "contig.bed");
+            tracker.addIntermediateFile(bed);
+
+            try (PrintWriter writer = PrintWriters.getPrintWriter(localBashScript);PrintWriter bedWriter = PrintWriters.getPrintWriter(bed))
             {
                 writer.println("#!/bin/bash");
                 writer.println("set -x");
@@ -260,7 +305,7 @@ public void execute(List<File> inputGvcfs, File outputVcf, PipelineOutputTracker
                 writer.println("\tghcr.io/dnanexus-rnd/glnexus:" + binVersion + " \\");
                 writer.println("\tglnexus_cli \\");
                 writer.println("\t--config " + configType + " \\");
-
+                writer.println("\t--bed /work/" + bed.getName() + " \\");
                 writer.println("\t--trim-uncalled-alleles \\");
 
                 if (maxRam != null)
@@ -290,6 +335,9 @@ public void execute(List<File> inputGvcfs, File outputVcf, PipelineOutputTracker
                     getLogger().debug("Deleting pre-existing GLnexus.DB dir");
                     FileUtils.deleteDirectory(dbDir);
                 }
+
+                // Create a single-contig BED file:
+                bedWriter.println(rec.getSequenceName() + "\t0\t" + rec.getSequenceLength());
             }
             catch (IOException e)
             {