Index: etc/defaults/rc.conf
===================================================================
--- etc/defaults/rc.conf
+++ etc/defaults/rc.conf
@@ -77,6 +77,8 @@
 # GELI disk encryption configuration.
 geli_devices=""		# List of devices to automatically attach in addition to
 			# GELI devices listed in /etc/fstab.
+geli_groups=""		# List of groups containing devices to automatically
+			# attach with the same keyfiles and passphrase
 geli_tries=""		# Number of times to attempt attaching geli device.
 			# If empty, kern.geom.eli.tries will be used.
 geli_default_flags=""	# Default flags for geli(8).
@@ -88,6 +90,11 @@
 #geli_da1_flags="-p -k /etc/geli/da1.keys"
 #geli_da1_autodetach="NO"
 #geli_mirror_home_flags="-k /etc/geli/home.keys"
+#geli_groups="storage backup"
+#geli_storage_flags="-k /etc/geli/storage.keys"
+#geli_storage_devices="ada0 ada1"
+#geli_backup_flags="-j /etc/geli/backup.passfile -k /etc/geli/backup.keys"
+#geli_backup_devices="ada2 ada3"
 
 root_rw_mount="YES"	# Set to NO to inhibit remounting root read-write.
 root_hold_delay="30"	# Time to wait for root mount hold release.
Index: etc/rc.d/geli
===================================================================
--- etc/rc.d/geli
+++ etc/rc.d/geli
@@ -34,7 +34,7 @@
 
 name="geli"
 desc="GELI disk encryption"
-start_precmd='[ -n "$(geli_make_list)" ]'
+start_precmd='[ -n "$(geli_make_list)" -o -n "$geli_groups" ]'
 start_cmd="geli_start"
 stop_cmd="geli_stop"
 required_modules="geom_eli:g_eli"
@@ -72,12 +72,38 @@
 			done
 		fi
 	done
+
+	for group in ${geli_groups}; do
+		group_=`ltr ${group} '/-' '_'`
+
+		eval "flags=\${geli_${group_}_flags}"
+		if [ -z "${flags}" ]; then
+			flags=${geli_default_flags}
+		fi
+
+		eval "providers=\${geli_${group_}_devices}"
+		if [ -z "${providers}" ]; then
+			echo "No devices listed in geli group ${group}."
+			break
+		fi
+
+		echo "Configuring Disk Encryption for geli group ${group}, containing ${providers}."
+		geli attach ${flags} ${providers}
+	done
 }
 
 geli_stop()
 {
 	devices=`geli_make_list`
 
+	for group in ${geli_groups}; do
+		group_=`ltr ${group} '/-' '_'`
+
+		eval "providers=\${geli_${group_}_devices}"
+
+		devices="${devices} ${providers}"
+	done
+
 	for provider in ${devices}; do
 		if [ -e "/dev/${provider}.eli" ]; then
 			umount "/dev/${provider}.eli" 2>/dev/null
Index: sbin/geom/class/eli/geli.8
===================================================================
--- sbin/geom/class/eli/geli.8
+++ sbin/geom/class/eli/geli.8
@@ -70,7 +70,7 @@
 .Op Fl dprv
 .Op Fl j Ar passfile
 .Op Fl k Ar keyfile
-.Ar prov
+.Ar prov ...
 .Nm
 .Cm detach
 .Op Fl fl
@@ -379,21 +379,24 @@
 features available.
 .El
 .It Cm attach
-Attach the given provider.
-The encrypted Master Key will be loaded from the metadata and decrypted
-using the given passphrase/keyfile and a new GEOM provider will be created
-using the given provider's name with an
+Attach the given providers.
+The encrypted Master Keys will be loaded from the metadata and decrypted
+using the given passphrase/keyfile and new GEOM providers will be created
+using the given providers' names with an
 .Qq .eli
 suffix.
+Multiple providers can only be attached with a single
+.Cm attach
+command if they all use the same passphrase and keyfiles.
 .Pp
 Additional options include:
 .Bl -tag -width ".Fl j Ar passfile"
 .It Fl d
-If specified, a decrypted provider will be detached automatically on last close.
+If specified, the decrypted providers will be detached automatically on last close.
 This can help with scarce memory so the user does not have to remember to detach the
-provider after unmounting the file system.
-It only works when the provider was opened for writing, so it will not work if
-the file system on the provider is mounted read-only.
+providers after unmounting the file system.
+It only works when the providers were opened for writing, so it will not work if
+the file system on the providers are mounted read-only.
 Probably a better choice is the
 .Fl l
 option for the
@@ -407,6 +410,7 @@
 option for the
 .Cm init
 subcommand.
+The same passfiles will be used for all listed providers.
 .It Fl k Ar keyfile
 Specifies a file which contains the keyfile component of the User Key
 (or part of it).
@@ -415,14 +419,15 @@
 option for the
 .Cm init
 subcommand.
+The same keyfiles will be used for all listed providers.
 .It Fl p
-Do not use a passphrase as a component of the User Key.
+Do not use a passphrase as a component of the User Keys.
 Cannot be combined with the
 .Fl j
 option.
 .It Fl r
-Attach read-only provider.
-It will not be opened for writing.
+Attach read-only providers.
+They will not be opened for writing.
 .El
 .It Cm detach
 Detach the given providers, which means remove the devfs entry
Index: sbin/geom/class/eli/geom_eli.c
===================================================================
--- sbin/geom/class/eli/geom_eli.c
+++ sbin/geom/class/eli/geom_eli.c
@@ -60,6 +60,13 @@
 
 #define	GELI_BACKUP_DIR	"/var/backups/"
 #define	GELI_ENC_ALGO	"aes"
+#define	BUFSIZE		1024
+
+/*
+ * Passphrase cached when attaching multiple providers, in order to be more
+ * user-friendly if they are using the same passphrase.
+ */
+static char cached_passphrase[BUFSIZE] = "";
 
 static void eli_main(struct gctl_req *req, unsigned flags);
 static void eli_init(struct gctl_req *req);
@@ -84,7 +91,7 @@
  *
  * init [-bgPTv] [-a aalgo] [-B backupfile] [-e ealgo] [-i iterations] [-l keylen] [-J newpassfile] [-K newkeyfile] [-s sectorsize] [-V version] prov
  * label - alias for 'init'
- * attach [-dprv] [-j passfile] [-k keyfile] prov
+ * attach [-dprv] [-j passfile] [-k keyfile] prov ...
  * detach [-fl] prov ...
  * stop - alias for 'detach'
  * onetime [-d] [-a aalgo] [-e ealgo] [-l keylen] prov
@@ -267,8 +274,6 @@
 
 static int verbose = 0;
 
-#define	BUFSIZE	1024
-
 static int
 eli_protect(struct gctl_req *req)
 {
@@ -474,6 +479,10 @@
 	bool nopassphrase;
 	int nfiles;
 
+	/*
+	 * Return error if the 'do not use passphrase' flag is given, and a
+	 * passfile was provided.
+	 */
 	nopassphrase =
 	    gctl_get_int(req, new ? "nonewpassphrase" : "nopassphrase");
 	if (nopassphrase) {
@@ -486,20 +495,32 @@
 		return (0);
 	}
 
+	/*
+	 * Return error if using a provider which does not require a passphrase,
+	 * but the 'do not use passphrase' flag was not given.
+	 */
 	if (!new && md->md_iterations == -1) {
 		gctl_error(req, "Missing -p flag.");
 		return (-1);
 	}
 	passbuf[0] = '\0';
-	nfiles = eli_genkey_files(req, new, "passfile", NULL, passbuf,
-	    sizeof(passbuf));
-	if (nfiles == -1)
-		return (-1);
-	else if (nfiles == 0) {
-		if (eli_genkey_passphrase_prompt(req, new, passbuf,
-		    sizeof(passbuf)) == -1) {
+
+	/* Use cached passphrase if defined. */
+	if (strcmp(cached_passphrase, "") != 0) {
+		memcpy(passbuf, cached_passphrase, sizeof(passbuf));
+	} else {
+		nfiles = eli_genkey_files(req, new, "passfile", NULL, passbuf,
+		    sizeof(passbuf));
+		if (nfiles == -1)
 			return (-1);
+		else if (nfiles == 0) {
+			if (eli_genkey_passphrase_prompt(req, new, passbuf,
+			    sizeof(passbuf)) == -1) {
+				return (-1);
+			}
 		}
+		/* Cache the passphrase for other providers. */
+		memcpy(cached_passphrase, passbuf, sizeof(passbuf));
 	}
 	/*
 	 * Field md_iterations equal to -1 means "choose some sane
@@ -876,37 +897,53 @@
 eli_attach(struct gctl_req *req)
 {
 	struct g_eli_metadata md;
-	unsigned char key[G_ELI_USERKEYLEN];
 	const char *prov;
 	off_t mediasize;
-	int nargs;
+	char param[16];
+	int i, nargs;
 
 	nargs = gctl_get_int(req, "nargs");
-	if (nargs != 1) {
-		gctl_error(req, "Invalid number of arguments.");
+	if (nargs == 0) {
+		gctl_error(req, "Too few arguments.");
 		return;
 	}
-	prov = gctl_get_ascii(req, "arg0");
 
-	if (eli_metadata_read(req, prov, &md) == -1)
-		return;
+	/* Use a 2D array for storing the derived keys (1 row per provider) */
+	unsigned char key[nargs][G_ELI_USERKEYLEN];
 
-	mediasize = g_get_mediasize(prov);
-	if (md.md_provsize != (uint64_t)mediasize) {
-		gctl_error(req, "Provider size mismatch.");
-		return;
-	}
+	/* Generate the derived key for each provider */
+	for (i = 0; i < nargs; i++) {
+		prov = gctl_get_ascii(req, "arg%d", i);
 
-	if (eli_genkey(req, &md, key, false) == NULL) {
-		bzero(key, sizeof(key));
-		return;
+		if (eli_metadata_read(req, prov, &md) == -1)
+			return;
+
+		mediasize = g_get_mediasize(prov);
+		if (md.md_provsize != (uint64_t)mediasize) {
+			gctl_error(req, "Provider size mismatch.");
+			return;
+		}
+
+		if (eli_genkey(req, &md, key[i], false) == NULL) {
+			bzero(key, sizeof(key));
+			return;
+		}
+
+		snprintf(param, sizeof(param), "key%d", i);
+		gctl_ro_param(req, param, sizeof(key[i]), key[i]);
 	}
 
-	gctl_ro_param(req, "key", sizeof(key), key);
 	if (gctl_issue(req) == NULL) {
-		if (verbose)
-			printf("Attached to %s.\n", prov);
+		if (verbose) {
+			printf("Attached to");
+			for (i = 0; i < nargs; i++) {
+				printf(" %s", gctl_get_ascii(req, "arg%d", i));
+			}
+			printf(".\n");
+		}
 	}
+
+	/* Clear each of the derived keys from the 2D array */
 	bzero(key, sizeof(key));
 }
 
Index: share/man/man5/rc.conf.5
===================================================================
--- share/man/man5/rc.conf.5
+++ share/man/man5/rc.conf.5
@@ -1931,6 +1931,13 @@
 Note that .eli devices from
 .Pa /etc/fstab
 are automatically appended to this list.
+.It Va geli_groups
+.Pq Vt str
+List of groups containing devices to automatically attach on boot with the same
+keyfiles and passphrase.
+This must be accompanied with a corresponding
+.Va geli_ Ns Ao Ar group Ac Ns Va _devices
+variable.
 .It Va geli_tries
 .Pq Vt int
 Number of times user is asked for the pass-phrase.
@@ -1944,6 +1951,8 @@
 when configuring disk encryption.
 Flags can be configured for every device separately by defining
 .Va geli_ Ns Ao Ar device Ac Ns Va _flags
+variable, and for every group separately by defining
+.Va geli_ Ns Ao Ar group Ac Ns Va _flags
 variable.
 .It Va geli_autodetach
 .Pq Vt str
Index: sys/geom/eli/g_eli_ctl.c
===================================================================
--- sys/geom/eli/g_eli_ctl.c
+++ sys/geom/eli/g_eli_ctl.c
@@ -57,8 +57,9 @@
 	struct g_provider *pp;
 	const char *name;
 	u_char *key, mkey[G_ELI_DATAIVKEYLEN];
+	char param[16], argname[16];
 	int *nargs, *detach, *readonly;
-	int keysize, error;
+	int i, keysize, error;
 	u_int nkey;
 
 	g_topology_assert();
@@ -68,8 +69,8 @@
 		gctl_error(req, "No '%s' argument.", "nargs");
 		return;
 	}
-	if (*nargs != 1) {
-		gctl_error(req, "Invalid number of arguments.");
+	if (*nargs == 0) {
+		gctl_error(req, "Too few arguments.");
 		return;
 	}
 
@@ -85,63 +86,72 @@
 		return;
 	}
 
-	name = gctl_get_asciiparam(req, "arg0");
-	if (name == NULL) {
-		gctl_error(req, "No 'arg%u' argument.", 0);
-		return;
-	}
-	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
-		name += strlen("/dev/");
-	pp = g_provider_by_name(name);
-	if (pp == NULL) {
-		gctl_error(req, "Provider %s is invalid.", name);
-		return;
-	}
-	error = g_eli_read_metadata(mp, pp, &md);
-	if (error != 0) {
-		gctl_error(req, "Cannot read metadata from %s (error=%d).",
-		    name, error);
-		return;
-	}
-	if (md.md_keys == 0x00) {
+	if (*detach && *readonly) {
 		bzero(&md, sizeof(md));
-		gctl_error(req, "No valid keys on %s.", pp->name);
+		gctl_error(req, "Options -d and -r are mutually exclusive.");
 		return;
 	}
 
-	key = gctl_get_param(req, "key", &keysize);
-	if (key == NULL || keysize != G_ELI_USERKEYLEN) {
-		bzero(&md, sizeof(md));
-		gctl_error(req, "No '%s' argument.", "key");
-		return;
-	}
+	/* Attach each provider in the request */
+	for (i = 0; i < *nargs; i++) {
+		snprintf(argname, sizeof(argname), "arg%d", i);
+		name = gctl_get_asciiparam(req, argname);
+		if (name == NULL) {
+			gctl_error(req, "No '%s' argument.", argname);
+			continue;
+		}
+		if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
+			name += strlen("/dev/");
+		pp = g_provider_by_name(name);
+		if (pp == NULL) {
+			gctl_error(req, "Provider %s is invalid.", name);
+			continue;
+		}
+		error = g_eli_read_metadata(mp, pp, &md);
+		if (error != 0) {
+			gctl_error(req, "Cannot read metadata from %s (error=%d).",
+			    name, error);
+			continue;
+		}
+		if (md.md_keys == 0x00) {
+			bzero(&md, sizeof(md));
+			gctl_error(req, "No valid keys on %s.", pp->name);
+			continue;
+		}
 
-	error = g_eli_mkey_decrypt(&md, key, mkey, &nkey);
-	bzero(key, keysize);
-	if (error == -1) {
-		bzero(&md, sizeof(md));
-		gctl_error(req, "Wrong key for %s.", pp->name);
-		return;
-	} else if (error > 0) {
-		bzero(&md, sizeof(md));
-		gctl_error(req, "Cannot decrypt Master Key for %s (error=%d).",
-		    pp->name, error);
-		return;
-	}
-	G_ELI_DEBUG(1, "Using Master Key %u for %s.", nkey, pp->name);
+		/* Get the derived key for this provider from the request */
+		snprintf(param, sizeof(param), "key%d", i);
+		key = gctl_get_param(req, param, &keysize);
+		if (key == NULL || keysize != G_ELI_USERKEYLEN) {
+			bzero(&md, sizeof(md));
+			gctl_error(req, "No '%s' argument.", param);
+			continue;
+		}
 
-	if (*detach && *readonly) {
+		/* Decrypt the master key for this provider */
+		error = g_eli_mkey_decrypt(&md, key, mkey, &nkey);
+		bzero(key, keysize);
+		if (error == -1) {
+			bzero(&md, sizeof(md));
+			gctl_error(req, "Wrong key for %s.", pp->name);
+			continue;
+		} else if (error > 0) {
+			bzero(&md, sizeof(md));
+			gctl_error(req, "Cannot decrypt Master Key for %s (error=%d).",
+			    pp->name, error);
+			continue;
+		}
+		G_ELI_DEBUG(1, "Using Master Key %u for %s.", nkey, pp->name);
+
+		/* Create the new GEOM provider using the master key */
+		if (*detach)
+			md.md_flags |= G_ELI_FLAG_WO_DETACH;
+		if (*readonly)
+			md.md_flags |= G_ELI_FLAG_RO;
+		g_eli_create(req, mp, pp, &md, mkey, nkey);
+		bzero(mkey, sizeof(mkey));
 		bzero(&md, sizeof(md));
-		gctl_error(req, "Options -d and -r are mutually exclusive.");
-		return;
 	}
-	if (*detach)
-		md.md_flags |= G_ELI_FLAG_WO_DETACH;
-	if (*readonly)
-		md.md_flags |= G_ELI_FLAG_RO;
-	g_eli_create(req, mp, pp, &md, mkey, nkey);
-	bzero(mkey, sizeof(mkey));
-	bzero(&md, sizeof(md));
 }
 
 static struct g_eli_softc *