diff --git a/src/db.c b/src/db.c
index f360607765cbec7fe21371eea58272ad0d6b6d2e..d545345cb9fdf893ad4546f99bfa4b1c8ccb364d 100644
--- a/src/db.c
+++ b/src/db.c
@@ -205,10 +205,22 @@ void delCommand(redisClient *c) {
     int deleted = 0, j;
 
     for (j = 1; j < c->argc; j++) {
+        if (server.ds_enabled) {
+            lookupKeyRead(c->db,c->argv[j]);
+            /* FIXME: this can be optimized a lot, no real need to load
+             * a possibly huge value. */
+        }
         if (dbDelete(c->db,c->argv[j])) {
             signalModifiedKey(c->db,c->argv[j]);
             server.dirty++;
             deleted++;
+        } else if (server.ds_enabled) {
+            if (cacheKeyMayExist(c->db,c->argv[j]) &&
+                dsExists(c->db,c->argv[j]))
+            {
+                cacheScheduleForFlush(c->db,c->argv[j]);
+                deleted = 1;
+            }
         }
     }
     addReplyLongLong(c,deleted);
diff --git a/src/diskstore.c b/src/diskstore.c
index 35c591d755110429fb8a2ece81ee2192a47c7cc4..6e59bc679cf704678945830b0d69b91ddef98fc1 100644
--- a/src/diskstore.c
+++ b/src/diskstore.c
@@ -262,6 +262,10 @@ int dsDel(redisDb *db, robj *key) {
 }
 
 int dsExists(redisDb *db, robj *key) {
+    char buf[1024];
+
+    dsKeyToPath(db,buf,key);
+    return access(buf,R_OK) == 0;
 }
 
 int dsFlushDb(int dbid) {
diff --git a/src/dscache.c b/src/dscache.c
index 05112cbb7303e2b7510f3bfc8e1661f8638dc2cb..9fc0f5e58f7c309aec380beb038eff2dc91e30e6 100644
--- a/src/dscache.c
+++ b/src/dscache.c
@@ -304,8 +304,10 @@ void vmThreadedIOCompletedJob(aeEventLoop *el, int fd, void *privdata,
             handleClientsBlockedOnSwappedKey(j->db,j->key);
             freeIOJob(j);
         } else if (j->type == REDIS_IOJOB_SAVE) {
-            redisAssert(j->val->storage == REDIS_DS_SAVING);
-            j->val->storage = REDIS_DS_MEMORY;
+            if (j->val) {
+                redisAssert(j->val->storage == REDIS_DS_SAVING);
+                j->val->storage = REDIS_DS_MEMORY;
+            }
             freeIOJob(j);
         }
         processed++;
@@ -362,11 +364,12 @@ void *IOThreadEntryPoint(void *arg) {
             j->val = dsGet(j->db,j->key,&expire);
             if (j->val) j->expire = expire;
         } else if (j->type == REDIS_IOJOB_SAVE) {
-            redisAssert(j->val->storage == REDIS_DS_SAVING);
-            if (j->val)
+            if (j->val) {
+                redisAssert(j->val->storage == REDIS_DS_SAVING);
                 dsSet(j->db,j->key,j->val);
-            else
+            } else {
                 dsDel(j->db,j->key);
+            }
         }
 
         /* Done: insert the job into the processed queue */
@@ -540,6 +543,15 @@ void cacheCron(void) {
     }
 }
 
+/* ============ Negative caching for diskstore objects ====================== */
+/* Since accesses to keys that don't exist with disk store cost us a disk
+ * access, we need to cache names of keys that do not exist but are frequently
+ * accessed. */
+int cacheKeyMayExist(redisDb *db, robj *key) {
+    /* FIXME: for now we just always return true. */
+    return 1;
+}
+
 /* ============ Virtual Memory - Blocking clients on missing keys =========== */
 
 /* This function makes the clinet 'c' waiting for the key 'key' to be loaded.
diff --git a/src/redis.h b/src/redis.h
index bb9aee7a991f3d4946746c51225902f62e15390f..15c192cfa02c6a2a72b2c098451047a6ef8b2146 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -808,6 +808,7 @@ void handleClientsBlockedOnSwappedKey(redisDb *db, robj *key);
 int cacheFreeOneEntry(void);
 void cacheScheduleForFlush(redisDb *db, robj *key);
 void cacheCron(void);
+int cacheKeyMayExist(redisDb *db, robj *key);
 
 /* Set data type */
 robj *setTypeCreate(robj *value);