diff --git a/server-src/amadmin.c b/server-src/amadmin.c
index 3653bab47e..9ca720d67a 100644
--- a/server-src/amadmin.c
+++ b/server-src/amadmin.c
@@ -52,6 +52,8 @@ int main(int argc, char **argv);
 void usage(void);
 static void estimate(int argc, char **argv);
 static void estimate_one(disk_t *dp);
+static void perfhist(int argc, char **argv);
+static void perfhist_one(disk_t *dp);
 void call_amadmin_perl(int argc, char **argv);
 void info(int argc, char **argv);
 void info_one(disk_t *dp);
@@ -146,6 +148,8 @@ static const struct {
 	T_(" [<hostname> [<disks>]* ]* # Export curinfo database to stdout.") },
     { "import", import_db,
 	T_("\t\t\t\t # Import curinfo database from stdin.") },
+    { "perfhist", perfhist,
+	T_(" [<hostname> [<disks>]* ]*\t# Output compression rate histogram") },
 };
 #define NCMDS G_N_ELEMENTS(cmdtab)
 
@@ -483,6 +487,60 @@ estimate(
 }
 
 
+/* ----------------------------------------------- */
+
+static void
+perfhist_one(
+    disk_t *	dp)
+{
+    char   *hostname = dp->host->hostname;
+    char   *diskname = dp->name;
+    char   *qhost = quote_string(hostname);
+    char   *qdisk = quote_string(diskname);
+    info_t  info;
+    double   *comp_avgs;
+    int     level, nhist, i;
+
+    get_info(hostname, diskname, &info);
+
+    for(level=0;level<=1;level++) {
+	setup_perf_hist(&info, level);
+        comp_avgs = (level==0) ? info.comp_avgs_full : info.comp_avgs_incr;
+        nhist = (level==0) ? info.nhist_full : info.nhist_incr;
+
+	if(nhist) {
+	    printf("%s %s %d", qhost, qdisk, level);
+	    for(i=0;i<64;i++) {
+		if(comp_avgs[i] > 0.0) printf(" %d(%f)",i,comp_avgs[i]);
+	    }
+	    printf("\n");
+	} else {
+	    printf("%s %s %d no history\n", qhost, qdisk, level);
+	}
+    }
+
+    amfree(qhost);
+    amfree(qdisk);
+}
+
+
+static void
+perfhist(
+    int		argc,
+    char **	argv)
+{
+    GList  *dlist;
+    disk_t *dp;
+
+    if(argc >= 4)
+	diskloop(argc, argv, "perfhist", perfhist_one);
+    else
+	for(dlist = diskq.head; dlist != NULL; dlist = dlist->next) {
+	    dp = dlist->data;
+	    perfhist_one(dp);
+	}
+}
+
 /* ----------------------------------------------- */
 
 void
diff --git a/server-src/infofile.c b/server-src/infofile.c
index 22beb8fdcb..769fb716d3 100644
--- a/server-src/infofile.c
+++ b/server-src/infofile.c
@@ -37,6 +37,8 @@
 #include "amutil.h"
 
 static void zero_info(info_t *);
+static int get_full_history(history_t *in, history_t **full);
+static int get_incr_history(history_t *in, history_t **incr);
 
   static char *infodir = NULL;
   static char *infofile = NULL;
@@ -609,6 +611,140 @@ perf_average(
     return sum / n;
 }
 
+int get_full_history(
+    history_t *in,
+    history_t **full)
+{
+    int n, i;
+    history_t *hist;
+
+    for(i=0,n=0;i<=NB_HISTORY;i++) {
+	if(in[i].level == 0) n++;
+    }
+    if(n == 0) return 0;
+
+    *full = hist = g_malloc(n * sizeof(history_t));
+    for(i=0,n=0;i<=NB_HISTORY;i++) {
+	if(in[i].level == 0) memcpy(&hist[n++], &in[i], sizeof(history_t));
+    }
+
+    return n;
+}
+
+int
+get_incr_history(
+    history_t *in,
+    history_t **incr)
+{
+    int n, i;
+    history_t *hist;
+
+    for(i=0,n=0;i<=NB_HISTORY;i++) {
+	if(in[i].level > 0) n++;
+    }
+    if(n == 0) return 0;
+
+    *incr = hist = g_malloc(n * sizeof(history_t));
+    for(i=0,n=0;i<=NB_HISTORY;i++) {
+	if(in[i].level > 0) memcpy(&hist[n++], &in[i], sizeof(history_t));
+    }
+
+    return n;
+}
+
+void
+setup_perf_hist(
+    info_t *	info,
+    int		level)
+{
+    history_t *history = 0;
+    int n, *nhist, i, bin, compn[64];
+    off_t size;
+    double *comp_avgs;
+
+    if(level == 0) {
+        comp_avgs = info->comp_avgs_full;
+	nhist = &info->nhist_full;
+	*nhist = n = get_full_history(info->history, &history);
+    } else {
+        comp_avgs = info->comp_avgs_incr;
+	nhist = &info->nhist_incr;
+	*nhist = n = get_incr_history(info->history, &history);
+    }
+    if(n == 0) return;
+
+    /* Total the rates into bins and count them */
+    memset(compn, '\0', sizeof(compn));
+    for(i=0; i<n && i<20; i++) {	/* Limit ourselves to the most recent 20 dumps */
+	size = history[i].size;
+	if(size == 0) size = 1;	/* Fudge zero into smallest bin */
+	bin = -1;
+	while (size >>= 1) bin++;
+	if(compn[bin]<3) {	/* Only take the most recent three dumps in each bin */
+	    comp_avgs[bin] += (double)(history[i].csize)/(double)(history[i].size);
+	    compn[bin]++;
+	}
+    }
+
+    /* Compute the averages */
+    for(bin=0;bin<64;bin++) {
+	if(comp_avgs[bin]>0.0) comp_avgs[bin] /= (double)compn[bin];
+    }
+}
+
+/*
+ * Average historical compression rate binned by original size
+ */
+double
+perf_hist(
+    info_t *	info,
+    int		level,
+    off_t	size,
+    double	def)
+{
+    double *comp_avgs, comp_avg, *compp;
+    int bin = -1, binh, binl, n, *nhist;
+
+    if(level == 0) {
+	comp_avgs = info->comp_avgs_full;
+	compp = info->full.comp;
+	nhist = &info->nhist_full;
+    } else {
+	comp_avgs = info->comp_avgs_incr;
+	compp = info->incr.comp;
+	nhist = &info->nhist_incr;
+    }
+    if(*nhist == -1) setup_perf_hist(info, level);
+    if(*nhist == 0) return def;
+
+    while (size >>= 1) bin++;
+    comp_avg = comp_avgs[bin];
+
+    /* If we don't have any history at this size try the surrounding bins */
+    binl = binh = bin;
+    binl--;
+    binh++;
+    while((comp_avg <= 0.0) && ((binl > 0) || (binh < 63))) {
+	n = 0;
+	if(binl >= 0 && comp_avgs[binl] > 0.0) {
+	    comp_avg += comp_avgs[binl];
+	    n++;
+	}
+	if(binh <= 63 && comp_avgs[binh] > 0.0) {
+	    comp_avg += comp_avgs[binh];
+            n++;
+	}
+	if(n > 0) comp_avg /= (double)n;
+	binl--;
+	binh++;
+    }
+
+    /* This shoudn't happen */
+    if(comp_avg <= 0.0) return def;
+
+    return comp_avg;
+}
+
 static void
 zero_info(
     info_t *info)
@@ -622,6 +758,8 @@ zero_info(
 	info->full.rate[i] = info->incr.rate[i] = -1.0;
     }
 
+    info->nhist_full = info->nhist_incr = -1;
+
     for(i = 0; i < DUMP_LEVELS; i++) {
 	info->inf[i].date = (time_t)-1;
     }
diff --git a/server-src/infofile.h b/server-src/infofile.h
index d7eaf9e821..a9b53c2d22 100644
--- a/server-src/infofile.h
+++ b/server-src/infofile.h
@@ -79,6 +79,10 @@ typedef struct info_s {
 #	define FORCE_LEVEL_1	8	/* force level 1 at next run */
     perf_t  full;
     perf_t  incr;
+    double comp_avgs_full[64];
+    double comp_avgs_incr[64];
+    int nhist_full;
+    int nhist_incr;
     stats_t inf[DUMP_LEVELS];
     int last_level, consecutive_runs;
     history_t history[NB_HISTORY+1];
@@ -91,6 +95,8 @@ void close_infofile(void);
 char *get_dumpdate(info_t *info, int level);
 char *get_based_on_timestamp(info_t *info, int lev);
 double perf_average(double *array, double def);
+void setup_perf_hist(info_t * info, int level);
+double perf_hist(info_t *info, int level, off_t size, double def);
 int get_info(char *hostname, char *diskname, info_t *info);
 int put_info(char *hostname, char *diskname, info_t *info);
 int del_info(char *hostname, char *diskname);
diff --git a/server-src/planner.c b/server-src/planner.c
index 6c983919fc..1d6838713c 100644
--- a/server-src/planner.c
+++ b/server-src/planner.c
@@ -1418,8 +1418,8 @@ est_csize(
         return;
     }
 
-    if (one_est->level == 0) ratio = ep->fullcomp;
-    else ratio = ep->incrcomp;
+    if (one_est->level == 0) ratio = perf_average(ep->info->full.comp, ep->fullcomp);
+    else ratio = perf_hist(ep->info, one_est->level, size, ep->incrcomp);
 
     /*
      * make sure over-inflated compression ratios don't throw off the