diff --git a/src/pmdas/mmv/GNUmakefile b/src/pmdas/mmv/GNUmakefile
index 6205a8a..63f778a 100644
--- a/src/pmdas/mmv/GNUmakefile
+++ b/src/pmdas/mmv/GNUmakefile
@@ -21,7 +21,6 @@ DOMAIN		= MMV
 CMDTARGET	= pmda$(IAM)$(EXECSUFFIX)
 LIBTARGET	= pmda_$(IAM).$(DSOSUFFIX)
 TARGETS		= $(CMDTARGET) $(LIBTARGET) mmvdump$(EXECSUFFIX)
-INSTTARGETS	= $(CMDTARGET) mmvdump$(EXECSUFFIX)
 
 CFILES		= mmv.c
 LSRCFILES	= pmns Install Remove README help root mmvdump.c
@@ -40,7 +39,7 @@ include $(BUILDRULES)
 
 install: default
 	$(INSTALL) -m 755 -d $(PMDADIR)
-	$(INSTALL) -m 755 $(INSTTARGETS) Install Remove $(PMDADIR)
+	$(INSTALL) -m 755 $(TARGETS) Install Remove $(PMDADIR)
 	$(INSTALL) -m 644 README root help pmns domain.h $(PMDADIR)
 
 $(CMDTARGET):	$(OBJECTS)
diff --git a/src/pmdas/mmv/Install b/src/pmdas/mmv/Install
index d663f1b..e4cbaa8 100755
--- a/src/pmdas/mmv/Install
+++ b/src/pmdas/mmv/Install
@@ -18,7 +18,7 @@
 . $PCP_SHARE_DIR/lib/pmdaproc.sh
 
 iam=mmv
-dso_opt=false
+dso_opt=true
 socket_opt=true
 socket_inet_def=2081
 pmda_interface=3
diff --git a/src/pmdas/mmv/mmv.c b/src/pmdas/mmv/mmv.c
index ef30ef0..d5fd366 100644
--- a/src/pmdas/mmv/mmv.c
+++ b/src/pmdas/mmv/mmv.c
@@ -30,7 +30,8 @@
 #include "./domain.h"
 #include <sys/stat.h>
 
-static pmdaInterface dispatch;
+#define NONLEAF(node)	((node)->pmid == PM_ID_NULL)
+
 static char mypath[MAXPATHLEN];
 static int isDSO = 1;
 
@@ -40,6 +41,7 @@ static pmdaIndom * indoms;
 static int incnt;
 
 static int reload;
+static __pmnsTree *pmns;
 static time_t statsdir_ts;		/* last statsdir timestamp */
 static char * prefix = "mmv";
 
@@ -67,100 +69,6 @@ typedef struct {
 static stats_t * slist;
 static int scnt;
 
-static int
-update_namespace(void)
-{
-    char script[3*MAXPATHLEN];
-    int sep = __pmPathSeparator();
-
-    snprintf(script, sizeof(script),
-		"%s%c" "lib" "%c" "ReplacePmnsSubtree %s %s%c" "%s.new",
-		pmGetConfig("PCP_SHARE_DIR"), sep, sep,
-		prefix, pmnsdir, sep, prefix);
-    if (system(script) == -1) {
-	__pmNotifyErr (LOG_ERR, "%s: cannot exec %s", pmProgname, script);
-	return 1;
-    }
-
-    return 0;
-}
-
-static void
-write_pmnspath(__pmnsNode *base, FILE *f)
-{
-    if (base && base->parent) {
-        write_pmnspath(base->parent, f);
-        fprintf(f, "%s.", base->name);
-    }
-}
-
-static void
-write_pmnsnode(__pmnsNode *base, FILE *f)
-{
-    __pmnsNode *np;
-
-    /* Print out full path to this part of the tree */
-    write_pmnspath(base->parent, f);
-    fprintf(f, "%s {\n", base->name);
-
-    /* Print out nodes at this level of the tree */
-    for (np = base->first; np != NULL; np = np->next) {
-        if (np->pmid == PM_ID_NULL)
-            fprintf(f, "\t%s\n", np->name);
-        else
-            fprintf(f, "\t%s\t\t%u:%u:%u\n", np->name,
-			pmid_domain(np->pmid),
-			pmid_cluster(np->pmid),
-			pmid_item(np->pmid));
-    }
-    fprintf(f, "}\n\n");
-
-    /* Print out all the children of this subtree */
-    for (np = base->first; np != NULL; np = np->next)
-        if (np->pmid == PM_ID_NULL)
-            write_pmnsnode(np, f);
-}
-
-static void
-write_pmnsfile(__pmnsTree *pmns)
-{
-    char tmppath[MAXPATHLEN];
-    char path[MAXPATHLEN];
-    char *fname = tmppath;
-    FILE *f = NULL;
-
-    putenv("TMPDIR=");	/* temp file must be in pmnsdir, for rename */
-
-#if HAVE_MKSTEMP
-    sprintf(tmppath, "%s%c%s-XXXXXX", pmnsdir, __pmPathSeparator(), prefix);
-    int fd = mkstemp(tmppath);
-    if (fd != -1)
-	f = fdopen(fd, "w");
-#else
-    fname = tempnam(pmnsdir, prefix);
-    if (fname != NULL) {
-	strncpy(tmppath, fname, sizeof(tmppath));
-	free(fname);
-	fname = tmppath;
-	f = fopen(fname, "w");
-    }
-#endif
-
-    if (f == NULL)
-	__pmNotifyErr(LOG_ERR, "%s: failed to generate temporary file %s: %s",
-			pmProgname, fname, strerror(errno));
-    else {
-	__pmnsNode *node;
-	for (node = pmns->root->first; node != NULL; node = node->next)
-	    write_pmnsnode(node, f);
-	fclose(f);
-	sprintf(path, "%s%c" "%s.new", pmnsdir, __pmPathSeparator(), prefix);
-	if (rename2(fname, path) < 0)
-	    __pmNotifyErr(LOG_ERR, "%s: cannot rename %s to %s - %s",
-			pmProgname, fname, path, strerror (errno));
-    }
-}
-
 /*
  * Choose an unused cluster ID while honouring specific requests.
  * If a specific (non-zero) cluster is requested we always use it.
@@ -193,24 +101,70 @@ choose_cluster(int requested, const char *path)
     return requested;
 }
 
+/*
+ * Fixup the parent pointers of the tree.
+ * Fill in the hash table with nodes from the tree.
+ * Hashing is done on pmid.
+ */
+static void
+mmv_reindex_hash(__pmnsTree *tree, __pmnsNode *root)
+{
+    __pmnsNode	*np;
+
+    for (np = root->first; np != NULL; np = np->next) {
+	np->parent = root;
+	if (np->pmid != PM_ID_NULL) {
+	    int i = np->pmid % tree->htabsize;
+	    np->hash = tree->htab[i];
+	    tree->htab[i] = np;
+	}
+	mmv_reindex_hash(tree, np);
+    }
+}
+
+/*
+ * "Make the average hash list no longer than 5, and the number
+ * of hash table entries not a multiple of 2, 3 or 5."
+ * [From __pmFixPMNSHashTab; without mark_all, dinks with pmids]
+ */
+static void
+mmv_rebuild_hash(__pmnsTree *tree, int numpmid)
+{
+    int htabsize = numpmid / 5;
+
+    if (htabsize % 2 == 0) htabsize++;
+    if (htabsize % 3 == 0) htabsize += 2;
+    if (htabsize % 5 == 0) htabsize += 2;
+    tree->htabsize = htabsize;
+    tree->htab = (__pmnsNode **)calloc(htabsize, sizeof(__pmnsNode *));
+    if (tree->htab == NULL)
+	__pmNotifyErr(LOG_ERR, "%s: out of memory in pmns rebuild - %s",
+			pmProgname, strerror(errno));
+    else
+	mmv_reindex_hash(tree, tree->root);
+}
+
 static void
-map_stats(void)
+map_stats(pmdaExt *pmda)
 {
-    __pmnsTree *pmns;
     struct dirent ** files;
     char name_reload[64];
     int need_reload = 0;
     int i, sts, num;
 
+    if (pmns)
+	__pmFreePMNS(pmns);
+
     if ((sts = __pmNewPMNS(&pmns)) < 0) {
 	__pmNotifyErr(LOG_ERR, "%s: failed to create new pmns: %s\n",
 			pmProgname, pmErrStr(sts));
+	pmns = NULL;
 	return;
     }
 
     mcnt = 1;
     snprintf(name_reload, sizeof(name_reload), "%s.reload", prefix);
-    __pmAddPMNSNode(pmns, pmid_build(dispatch.domain, 0, 0), name_reload);
+    __pmAddPMNSNode(pmns, pmid_build(pmda->e_domain, 0, 0), name_reload);
 
     if (indoms != NULL) {
 	for (i = 0; i < incnt; i++)
@@ -359,7 +313,7 @@ map_stats(void)
 
 			metrics[mcnt].m_user = ml + k;
 			metrics[mcnt].m_desc.pmid = pmid_build(
-				dispatch.domain, s->cluster, ml[k].item);
+				pmda->e_domain, s->cluster, ml[k].item);
 
 			if (ml[k].type == MMV_TYPE_ELAPSED) {
 			    pmUnits unit = PMDA_PMUNITS(0,1,0,0,PM_TIME_USEC,0);
@@ -378,18 +332,20 @@ map_stats(void)
 			metrics[mcnt].m_desc.indom =
 				(!ml[k].indom || ml[k].indom == PM_INDOM_NULL) ?
 					PM_INDOM_NULL :
-					pmInDom_build(dispatch.domain,
+					pmInDom_build(pmda->e_domain,
 					(s->cluster << 11) | ml[k].indom);
 
 			strcat(name, ml[k].name);
 			__pmAddPMNSNode(pmns, pmid_build(
-				dispatch.domain, s->cluster, ml[k].item),
+				pmda->e_domain, s->cluster, ml[k].item),
 				name);
 			mcnt++;
 		    }
 		} else {
 		    __pmNotifyErr(LOG_ERR, "%s: cannot grow metric list",
 				  pmProgname);
+		    if (isDSO)
+			return;
 		    exit(1);
 		}
 		break;
@@ -405,7 +361,7 @@ map_stats(void)
 
 		    for (k = 0; k < toc[j].count; k++) {
 			ip = &indoms[incnt + k];
-			ip->it_indom = pmInDom_build(dispatch.domain,
+			ip->it_indom = pmInDom_build(pmda->e_domain,
 				(slist[i].cluster << 11) | id[k].serial);
 			ip->it_numinst = id[k].count;
 			ip->it_set = (pmdaInstid *)
@@ -422,6 +378,8 @@ map_stats(void)
 			    __pmNotifyErr(LOG_ERR, 
 				"%s: cannot get memory for instance list",
 				pmProgname);
+			    if (isDSO)
+				return;
 			    exit(1);
 			}
 		    }
@@ -429,6 +387,8 @@ map_stats(void)
 		} else {
 		    __pmNotifyErr(LOG_ERR, "%s: cannot grow indom list",
 				  pmProgname);
+		    if (isDSO)
+			return;
 		    exit(1);
 		}
 		break;
@@ -445,9 +405,7 @@ map_stats(void)
 	}
     }
 
-    write_pmnsfile(pmns);
-    __pmFreePMNS(pmns);
-
+    mmv_rebuild_hash(pmns, mcnt);	/* for reverse (pmid->name) lookups */
     reload = need_reload;
 }
 
@@ -549,8 +507,8 @@ mmv_fetchCallBack(pmdaMetric *mdesc, unsigned int inst, pmAtomValue *atom)
     return 0;
 }
 
-static int
-mmv_reload_maybe(void)
+static void
+mmv_reload_maybe(pmdaExt *pmda)
 {
     int i;
     struct stat s;
@@ -572,14 +530,8 @@ mmv_reload_maybe(void)
     }
 
     if (need_reload) {
-	/* something changed - reload */
-	pmdaExt * pmda = dispatch.version.two.ext; /* we know it is V.2 */
-
-	/* Note: this line means we cannot run as shared library */
-	__pmSendError(pmda->e_outfd, PDU_BINARY, PM_ERR_PMDANOTREADY);
-
 	__pmNotifyErr(LOG_INFO, "%s: reloading", pmProgname);
-	map_stats();
+	map_stats(pmda);
 
 	pmda->e_indoms = indoms;
 	pmda->e_nindoms = incnt;
@@ -590,19 +542,14 @@ mmv_reload_maybe(void)
 	__pmNotifyErr(LOG_INFO, 
 		      "%s: %d metrics and %d indoms after reload", 
 		      pmProgname, mcnt, incnt);
-
-	reload = update_namespace();
     }
-
-    return need_reload;
 }
 
 /* Intercept request for descriptor and check if we'd have to reload */
 static int
 mmv_desc(pmID pmid, pmDesc *desc, pmdaExt *ep)
 {
-    if (mmv_reload_maybe())
-	return PM_ERR_PMDAREADY;
+    mmv_reload_maybe(ep);
     return pmdaDesc(pmid, desc, ep);
 }
 
@@ -612,9 +559,8 @@ mmv_text(int ident, int type, char **buffer, pmdaExt *ep)
     if (type & PM_TEXT_INDOM)
 	return PM_ERR_TEXT;
 
-    if (mmv_reload_maybe())
-	return PM_ERR_PMDAREADY;
-    else if (pmid_cluster(ident) == 0)
+    mmv_reload_maybe(ep);
+    if (pmid_cluster(ident) == 0)
 	return pmdaText(ident, type, buffer, ep);
     else {
 	mmv_disk_metric_t * m;
@@ -643,16 +589,14 @@ static int
 mmv_instance(pmInDom indom, int inst, char *name, 
 	     __pmInResult **result, pmdaExt *ep)
 {
-    if (mmv_reload_maybe())
-	return PM_ERR_PMDAREADY;
+    mmv_reload_maybe(ep);
     return pmdaInstance(indom, inst, name, result, ep);
 }
 
 static int
 mmv_fetch(int numpmid, pmID pmidlist[], pmResult **resp, pmdaExt *pmda)
 {
-    if (mmv_reload_maybe())
-	return PM_ERR_PMDAREADY;
+    mmv_reload_maybe(pmda);
     return pmdaFetch(numpmid, pmidlist, resp, pmda);
 }
 
@@ -661,8 +605,7 @@ mmv_store(pmResult *result, pmdaExt *ep)
 {
     int i, m;
 
-    if (mmv_reload_maybe())
-	return PM_ERR_PMDAREADY;
+    mmv_reload_maybe(ep);
 
     for (i = 0; i < result->numpmid; i++) {
 	pmValueSet * vsp = result->vset[i];
@@ -692,6 +635,219 @@ mmv_store(pmResult *result, pmdaExt *ep)
     return 0;
 }
 
+static __pmnsNode *
+mmv_lookup_node(__pmnsNode *node, char *name)
+{
+    while (node != NULL) {
+	size_t length = strlen(node->name);
+	if (strncmp(name, node->name, length) == 0) {
+	    if (name[length] == '\0')
+		return node;
+	    if (name[length] == '.' && NONLEAF(node))
+		return mmv_lookup_node(node->first, name + length + 1);
+	}
+	node = node->next;
+    }
+    return NULL;
+}
+
+static int
+mmv_pmid(char *name, pmID *pmid, pmdaExt *pmda)
+{
+    __pmnsNode *node;
+
+    mmv_reload_maybe(pmda);
+    if ((node = mmv_lookup_node(pmns->root->first, name)) == NULL)
+	return PM_ERR_NAME;
+    if (NONLEAF(node))
+	return PM_ERR_NAME;
+    *pmid = node->pmid;
+    return 0;
+}
+
+static char *
+mmv_absolute_name(__pmnsNode *node, char *buffer)
+{
+    if (node && node->parent) {
+	buffer = mmv_absolute_name(node->parent, buffer);
+	strcpy(buffer, node->name);
+	buffer += strlen(node->name);
+	*buffer++ = '.';
+    }
+    return buffer;
+}
+
+static int
+mmv_name(pmID pmid, char ***nameset, pmdaExt *pmda)
+{
+    __pmnsNode *hashchain, *node, *parent;
+    int nmatch = 0, length = 0;
+    char *p, **list;
+
+    mmv_reload_maybe(pmda);
+    if (!pmns)
+	return PM_ERR_PMID;
+
+    hashchain = pmns->htab[pmid % pmns->htabsize];
+    for (node = hashchain; node != NULL; node = node->hash) {
+	if (node->pmid == pmid) {
+	    for (parent = node; parent->parent; parent = parent->parent)
+		length += strlen(parent->name) + 1;
+	    nmatch++;
+	}
+    }
+
+    if (nmatch == 0)
+	return PM_ERR_PMID;
+
+    length += nmatch * sizeof(char *);		/* pointers to names */
+
+    if ((list = (char **)malloc(length)) == NULL)
+	return -errno;
+
+    p = (char *)&list[nmatch];
+    nmatch = 0;
+    for (node = hashchain; node != NULL; node = node->hash) {
+	if (node->pmid == pmid) {
+	    list[nmatch++] = p;
+	    p = mmv_absolute_name(node, p);
+	    *(p-1) = '\0';	/* overwrite final '.' */
+	}
+    }
+
+    *nameset = list;
+    return nmatch;
+}
+
+static int
+mmv_children_relative(__pmnsNode *base, char ***offspring, int **status)
+{
+    __pmnsNode *node;
+    char **list, *p;
+    int *leaf, length = 0, nmatch = 0;
+ 
+    for (node = base; node != NULL; node = node->next, nmatch++)
+	length += strlen(node->name) + 1;
+    length += nmatch * sizeof(char *);	/* pointers to names */
+    if ((list = (char **)malloc(length)) == NULL)
+	return -errno;
+    if ((leaf = (int *)malloc(nmatch * sizeof(int*))) == NULL) {
+	free(list);
+	return -errno;
+    }
+    p = (char *)&list[nmatch];
+    nmatch = 0;
+    for (node = base; node != NULL; node = node->next, nmatch++) {
+	leaf[nmatch] = NONLEAF(node) ? PMNS_NONLEAF_STATUS : PMNS_LEAF_STATUS;
+	list[nmatch] = p;
+	strcpy(p, node->name);
+	p += strlen(node->name);
+	*p++ = '\0';
+    }
+
+    *offspring = list;
+    *status = leaf;
+    return nmatch;
+}
+
+static void
+mmv_children_getsize(__pmnsNode *base, int kids, int *length, int *nmetrics)
+{
+    __pmnsNode *node, *parent;
+
+    /* walk to every leaf & then add its (absolute name) length */
+    for (node = base; node != NULL; node = node->next) {
+	if (NONLEAF(node)) {
+	    mmv_children_getsize(node->first, 1, length, nmetrics);
+	    continue;
+	}
+	for (parent = node; parent->parent; parent = parent->parent)
+	    *length += strlen(parent->name) + 1;
+	(*nmetrics)++;
+	if (!kids)
+	    break;
+    }
+}
+
+/*
+ * Fill the pmdaChildren buffers - names and leaf status.  Called recursively
+ * to descend down to all leaf nodes.  Offset parameter is the current offset
+ * into the name list buffer, and its also returned at the end of each call -
+ * it keeps track of where the next name is to start in (list) output buffer.
+ */
+static char *
+mmv_children_getlist(__pmnsNode *base, int kids, int *nmetrics, char *p, char **list, int *leaf)
+{
+    __pmnsNode *node;
+    int count = *nmetrics;
+    char *start = p;
+
+    for (node = base; node != NULL; node = node->next) {
+	if (NONLEAF(node)) {
+	    p = mmv_children_getlist(node->first, 1, &count, p, list, leaf);
+	    start = p;
+	    continue;
+	}
+	leaf[count] = PMNS_LEAF_STATUS;
+	list[count] = start;
+	p = mmv_absolute_name(node, p);
+	*(p-1) = '\0';	/* overwrite final '.' */
+	start = p;
+	count++;
+	if (!kids)
+	    break;
+    }
+    *nmetrics = count;
+    return p;
+}
+
+static int
+mmv_children_absolute(__pmnsNode *node, char ***offspring, int **status)
+{
+    char *p, **list;
+    int *leaf, descend = 0, length = 0, nmetrics = 0;
+
+    if (NONLEAF(node)) {
+	node = node->first;
+	descend = 1;
+    }
+    mmv_children_getsize(node, descend, &length, &nmetrics);
+ 
+    length += nmetrics * sizeof(char *);	/* pointers to names */
+    if ((list = (char **)malloc(length)) == NULL)
+	return -errno;
+    if ((leaf = (int *)malloc(nmetrics * sizeof(int*))) == NULL) {
+	free(list);
+	return -errno;
+    }
+
+    p = (char *)&list[nmetrics];
+    nmetrics = 0;	/* start at the start */
+    mmv_children_getlist(node, descend, &nmetrics, p, list, leaf);
+
+    *offspring = list;
+    *status = leaf;
+    return nmetrics;
+}
+
+static int
+mmv_children(char *name, int traverse, char ***offspring, int **status, pmdaExt *pmda)
+{
+    __pmnsNode *node;
+
+    mmv_reload_maybe(pmda);
+    if (!pmns)
+	return PM_ERR_NAME;
+
+    __pmNotifyErr(LOG_INFO, "%s: children of %s (traverse=%d)", pmProgname, name, traverse);
+
+    if ((node = mmv_lookup_node(pmns->root->first, name)) == NULL)
+	return PM_ERR_NAME;
+
+    if (traverse == 0)
+	return mmv_children_relative(node->first, offspring, status);
+    return mmv_children_absolute(node, offspring, status);
+}
 
 void
 mmv_init(pmdaInterface *dp)
@@ -701,7 +857,7 @@ mmv_init(pmdaInterface *dp)
     if (isDSO) {
 	snprintf(mypath, sizeof(mypath), "%s%c" "mmv" "%c" "help",
 		pmGetConfig("PCP_PMDAS_DIR"), sep, sep);
-	pmdaDSO(dp, PMDA_INTERFACE_3, "MMV DSO", mypath);
+	pmdaDSO(dp, PMDA_INTERFACE_4, "mmv", mypath);
     }
 
     pcptmpdir = pmGetConfig("PCP_TMP_DIR");
@@ -729,11 +885,14 @@ mmv_init(pmdaInterface *dp)
 	    exit(0);
 	}
 
-	dp->version.two.fetch = mmv_fetch;
-	dp->version.two.store = mmv_store;
-	dp->version.two.desc = mmv_desc;
-	dp->version.two.text = mmv_text;
-	dp->version.two.instance = mmv_instance;
+	dp->version.four.fetch = mmv_fetch;
+	dp->version.four.store = mmv_store;
+	dp->version.four.desc = mmv_desc;
+	dp->version.four.text = mmv_text;
+	dp->version.four.instance = mmv_instance;
+	dp->version.four.pmid = mmv_pmid;
+	dp->version.four.name = mmv_name;
+	dp->version.four.children = mmv_children;
 
 	pmdaSetFetchCallBack(dp, mmv_fetchCallBack);
 
@@ -762,6 +921,8 @@ main(int argc, char **argv)
     int		err = 0;
     int		sep = __pmPathSeparator();
     char	logfile[32];
+    char	p[] = "mmv", *prefix = p;
+    pmdaInterface dispatch = { 0 };
 
     isDSO = 0;
     __pmSetProgname(argv[0]);
@@ -770,7 +931,7 @@ main(int argc, char **argv)
     snprintf(mypath, sizeof(mypath), "%s%c" "%s%c" "help",
 		pmGetConfig("PCP_PMDAS_DIR"), sep, prefix, sep);
     snprintf(logfile, sizeof(logfile), "%s.log", prefix);
-    pmdaDaemon(&dispatch, PMDA_INTERFACE_3, pmProgname, MMV, logfile, mypath);
+    pmdaDaemon(&dispatch, PMDA_INTERFACE_4, pmProgname, MMV, logfile, mypath);
 
     if ((pmdaGetOpt(argc, argv, "D:d:l:?", &dispatch, &err) != EOF) ||
 	err || argc != optind)
diff --git a/src/pmdas/mmv/pmns b/src/pmdas/mmv/pmns
index 38241f0..4c3cb82 100644
--- a/src/pmdas/mmv/pmns
+++ b/src/pmdas/mmv/pmns
@@ -1,8 +1,5 @@
 /*
- * Metrics for MMV PMDA
- *
+ * Metrics for MMV PMDA - all dynamic!
  */
 
-mmv {
-	reload	MMV:0:0
-}
+mmv	MMV:*:*