diff --git a/doc/man-pages/pod1/fs_flushall.pod b/doc/man-pages/pod1/fs_flushall.pod
index 92a621ebc1..38a9144611 100644
--- a/doc/man-pages/pod1/fs_flushall.pod
+++ b/doc/man-pages/pod1/fs_flushall.pod
@@ -18,10 +18,6 @@ B<fs flusha> [B<-h>]
 
 The B<fs flushall> command flushes all data from the AFS cache.
 
-=head1 CAUTIONS
-
-This command is only available on Windows.
-
 =head1 OPTIONS
 
 =over 4
diff --git a/src/afs/afs_pioctl.c b/src/afs/afs_pioctl.c
index b6b2009347..df194b56a9 100644
--- a/src/afs/afs_pioctl.c
+++ b/src/afs/afs_pioctl.c
@@ -277,6 +277,7 @@ DECL_PIOCTL(PRemoveMount);
 DECL_PIOCTL(PGetCellStatus);
 DECL_PIOCTL(PSetCellStatus);
 DECL_PIOCTL(PFlushVolumeData);
+DECL_PIOCTL(PFlushAllVolumeData);
 DECL_PIOCTL(PGetVnodeXStatus);
 DECL_PIOCTL(PGetVnodeXStatus2);
 DECL_PIOCTL(PSetSysName);
@@ -420,6 +421,7 @@ static pioctlFunction CpioctlSw[] = {
     PBogus,                     /* 11 */
     PPrecache,                  /* 12 */
     PGetPAG,                    /* 13 */
+    PFlushAllVolumeData,        /* 14 */
 };
 
 static pioctlFunction OpioctlSw[]  = {
@@ -3442,46 +3444,27 @@ DECL_PIOCTL(PSetCellStatus)
     return 0;
 }
 
-/*!
- * VIOC_FLUSHVOLUME (37) - Flush whole volume's data
- *
- * \ingroup pioctl
- *
- * \param[in] ain	not in use (args in avc)
- * \param[out] aout	not in use
- *
- * \retval EINVAL	Error if some of the standard args aren't set
- * \retval EIO		Error if the afs daemon hasn't started yet
- *
- * \post
- * 	Flush all cached contents of a volume.  Exactly what stays and what
- * 	goes depends on the platform.
- *
- * \notes
- * 	Does not flush a file that a user has open and is using, because
- * 	it will be re-created on next write.  Also purges the dnlc,
- * 	because things are screwed up.
- */
-DECL_PIOCTL(PFlushVolumeData)
+static void
+FlushVolumeData(struct VenusFid *afid, afs_ucred_t * acred)
 {
     afs_int32 i;
     struct dcache *tdc;
     struct vcache *tvc;
     struct volume *tv;
-    afs_int32 cell, volume;
+    afs_int32 all = 0;
+    afs_int32 cell = 0;
+    afs_int32 volume = 0;
     struct afs_q *tq, *uq;
 #ifdef AFS_DARWIN80_ENV
     vnode_t vp;
 #endif
 
-    AFS_STATCNT(PFlushVolumeData);
-    if (!avc)
-	return EINVAL;
-    if (!afs_resourceinit_flag)	/* afs daemons haven't started yet */
-	return EIO;		/* Inappropriate ioctl for device */
-
-    volume = avc->f.fid.Fid.Volume;	/* who to zap */
-    cell = avc->f.fid.Cell;
+    if (!afid) {
+	all = 1;
+    } else {
+	volume = afid->Fid.Volume;	/* who to zap */
+	cell = afid->Cell;
+    }
 
     /*
      * Clear stat'd flag from all vnodes from this volume; this will
@@ -3489,11 +3472,11 @@ DECL_PIOCTL(PFlushVolumeData)
      */
  loop:
     ObtainReadLock(&afs_xvcache);
-    i = VCHashV(&avc->f.fid);
-    for (tq = afs_vhashTV[i].prev; tq != &afs_vhashTV[i]; tq = uq) {
+    for (i = (afid ? VCHashV(afid) : 0); i < VCSIZE; i = (afid ? VCSIZE : i+1)) {
+	for (tq = afs_vhashTV[i].prev; tq != &afs_vhashTV[i]; tq = uq) {
 	    uq = QPrev(tq);
 	    tvc = QTOVH(tq);
-	    if (tvc->f.fid.Fid.Volume == volume && tvc->f.fid.Cell == cell) {
+	    if (all || (tvc->f.fid.Fid.Volume == volume && tvc->f.fid.Cell == cell)) {
 		if (tvc->f.states & CVInit) {
 		    ReleaseReadLock(&afs_xvcache);
 		    afs_osi_Sleep(&tvc->f.states);
@@ -3522,7 +3505,7 @@ DECL_PIOCTL(PFlushVolumeData)
 		afs_BozonLock(&tvc->pvnLock, tvc);	/* Since afs_TryToSmush will do a pvn_vptrunc */
 #endif
 		ObtainWriteLock(&tvc->lock, 232);
-		afs_ResetVCache(tvc, *acred, 1);
+		afs_ResetVCache(tvc, acred, 1);
 		ReleaseWriteLock(&tvc->lock);
 #ifdef AFS_BOZONLOCK_ENV
 		afs_BozonUnlock(&tvc->pvnLock, tvc);
@@ -3536,6 +3519,7 @@ DECL_PIOCTL(PFlushVolumeData)
 		AFS_FAST_RELE(tvc);
 	    }
 	}
+    }
     ReleaseReadLock(&afs_xvcache);
 
 
@@ -3549,7 +3533,7 @@ DECL_PIOCTL(PFlushVolumeData)
 	}
 	if (tdc->refCount <= 1) {    /* too high, in use by running sys call */
 	    ReleaseReadLock(&tdc->tlock);
-	    if (tdc->f.fid.Fid.Volume == volume && tdc->f.fid.Cell == cell) {
+	    if (all || (tdc->f.fid.Fid.Volume == volume && tdc->f.fid.Cell == cell)) {
 		if (!(afs_indexFlags[i] & (IFDataMod | IFFree | IFDiscarded))) {
 		    /* if the file is modified, but has a ref cnt of only 1,
 		     * then someone probably has the file open and is writing
@@ -3573,7 +3557,7 @@ DECL_PIOCTL(PFlushVolumeData)
     ObtainReadLock(&afs_xvolume);
     for (i = 0; i < NVOLS; i++) {
 	for (tv = afs_volumes[i]; tv; tv = tv->next) {
-	    if (tv->volume == volume) {
+	    if (all || tv->volume == volume) {
 		afs_ResetVolumeInfo(tv);
 		break;
 	    }
@@ -3584,9 +3568,70 @@ DECL_PIOCTL(PFlushVolumeData)
     /* probably, a user is doing this, probably, because things are screwed up.
      * maybe it's the dnlc's fault? */
     osi_dnlc_purge();
+}
+
+/*!
+ * VIOC_FLUSHVOLUME (37) - Flush whole volume's data
+ *
+ * \ingroup pioctl
+ *
+ * \param[in] ain	not in use (args in avc)
+ * \param[out] aout	not in use
+ *
+ * \retval EINVAL	Error if some of the standard args aren't set
+ * \retval EIO		Error if the afs daemon hasn't started yet
+ *
+ * \post
+ * 	Flush all cached contents of a volume.  Exactly what stays and what
+ * 	goes depends on the platform.
+ *
+ * \notes
+ * 	Does not flush a file that a user has open and is using, because
+ * 	it will be re-created on next write.  Also purges the dnlc,
+ * 	because things are screwed up.
+ */
+DECL_PIOCTL(PFlushVolumeData)
+{
+    AFS_STATCNT(PFlushVolumeData);
+    if (!avc)
+	return EINVAL;
+    if (!afs_resourceinit_flag)	/* afs daemons haven't started yet */
+	return EIO;		/* Inappropriate ioctl for device */
+
+    FlushVolumeData(&avc->f.fid, *acred);
     return 0;
 }
 
+/*!
+ * VIOC_FLUSHALL (14) - Flush whole volume's data for all volumes
+ *
+ * \ingroup pioctl
+ *
+ * \param[in] ain	not in use
+ * \param[out] aout	not in use
+ *
+ * \retval EINVAL	Error if some of the standard args aren't set
+ * \retval EIO		Error if the afs daemon hasn't started yet
+ *
+ * \post
+ * 	Flush all cached contents.  Exactly what stays and what
+ * 	goes depends on the platform.
+ *
+ * \notes
+ * 	Does not flush a file that a user has open and is using, because
+ * 	it will be re-created on next write.  Also purges the dnlc,
+ * 	because things are screwed up.
+ */
+DECL_PIOCTL(PFlushAllVolumeData)
+{
+    AFS_STATCNT(PFlushAllVolumeData);
+
+    if (!afs_resourceinit_flag)	/* afs daemons haven't started yet */
+	return EIO;		/* Inappropriate ioctl for device */
+
+    FlushVolumeData(NULL, *acred);
+    return 0;
+}
 
 /*!
  * VIOCGETVCXSTATUS (41) - gets vnode x status
diff --git a/src/afs/afs_stats.h b/src/afs/afs_stats.h
index 11e242a92d..1c0feb37b3 100644
--- a/src/afs/afs_stats.h
+++ b/src/afs/afs_stats.h
@@ -656,7 +656,8 @@ struct afs_MeanStats {
     AFS_CS(BPrefetchNoCache)	/* afs_daemons.c */ \
     AFS_CS(afs_ReadNoCache)	/* osi_vnodeops.c */ \
     AFS_CS(PSetTokens2)		/* afs_pioctl.c */ \
-    AFS_CS(PPrefetchFromTape)   /* afs_pioctl.c */
+    AFS_CS(PPrefetchFromTape)   /* afs_pioctl.c */ \
+    AFS_CS(PFlushAllVolumeData)	/* afs_pioctl.c */
 
 struct afs_CMCallStats {
 #define AFS_CS(call) afs_int32 C_ ## call;
diff --git a/src/config/vioc.h b/src/config/vioc.h
index caf140fb38..f6a40a3b31 100644
--- a/src/config/vioc.h
+++ b/src/config/vioc.h
@@ -104,6 +104,7 @@
 #define VIOC_NEWUUID            _CVICEIOCTL(9)  /* new uuid */
 #define VIOCPRECACHE            _CVICEIOCTL(12) /* precache size */
 #define VIOC_GETPAG             _CVICEIOCTL(13) /* get pag value */
+#define VIOC_FLUSHALL           _CVICEIOCTL(14) /* flush all volume data */
 
 /* OpenAFS-specific 'O' pioctl's */
 #define VIOC_NFS_NUKE_CREDS	_OVICEIOCTL(1)	/* nuke creds for all PAG's */
diff --git a/src/venus/fs.c b/src/venus/fs.c
index 9dc26badd1..c05bfe50ca 100644
--- a/src/venus/fs.c
+++ b/src/venus/fs.c
@@ -1314,6 +1314,25 @@ FlushVolumeCmd(struct cmd_syndesc *as, void *arock)
     return error;
 }
 
+static int
+FlushAllVolumesCmd(struct cmd_syndesc *as, void *arock)
+{
+    afs_int32 code;
+    struct ViceIoctl blob;
+    int error = 0;
+
+    blob.in_size = 0;
+    blob.out_size = AFS_PIOCTL_MAXSIZE;
+    blob.out = space;
+
+    code = pioctl(NULL, VIOC_FLUSHALL, &blob, 0);
+    if (code) {
+	fprintf(stderr, "Error flushing all volumes\n");
+	error = 1;
+    }
+    return error;
+}
+
 /*
  * The Windows version of UuidCmd displays the UUID.
  * When the UNIX version is updated to do the same
@@ -3869,6 +3888,8 @@ defect 3069
 			  "flush all data in volume");
     cmd_AddParm(ts, "-path", CMD_LIST, CMD_OPTIONAL, "dir/file path");
 
+    cmd_CreateSyntax("flushall", FlushAllVolumesCmd, NULL, "flush all data from the cache");
+
     ts = cmd_CreateSyntax("sysname", SysNameCmd, NULL,
 			  "get/set sysname (i.e. @sys) value");
     cmd_AddParm(ts, "-newsys", CMD_LIST, CMD_OPTIONAL, "new sysname");