cli/glusterd: Added support for dispersed volumes

Two new options have been added to the 'create' command of the cli
interface:

    disperse [<count>] redundancy <count>

Both are optional. A dispersed volume is created by specifying, at
least, one of them. If 'disperse' is missing or it's present but
'<count>' does not, the number of bricks enumerated in the command
line is taken as the disperse count.

If 'redundancy' is missing, the lowest optimal value is assumed. A
configuration is considered optimal (for most workloads) when the
disperse count - redundancy count is a power of 2. If the resulting
redundancy is 1, the volume is created normally, but if it's greater
than 1, a warning is shown to the user and he/she must answer yes/no
to continue volume creation. If there isn't any optimal value for
the given number of bricks, a warning is also shown and, if the user
accepts, a redundancy of 1 is used.

If 'redundancy' is specified and the resulting volume is not optimal,
another warning is shown to the user.

A distributed-disperse volume can be created using a number of bricks
multiple of the disperse count.

Change-Id: Iab93efbe78e905cdb91f54f3741599f7ea6645e4
BUG: 1118629
Signed-off-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-on: http://review.gluster.org/7782
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-brick-ops.c b/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
index 452df759ad4..089c7d637c9 100644
--- a/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
+++ b/xlators/mgmt/glusterd/src/glusterd-brick-ops.c
@@ -169,6 +169,12 @@ gd_addbr_validate_stripe_count (glusterd_volinfo_t *volinfo, int stripe_count,
                         }
                 }
                 break;
+        case GF_CLUSTER_TYPE_DISPERSE:
+                snprintf (err_str, err_len, "Volume %s cannot be converted "
+                                            "from dispersed to striped-"
+                                            "dispersed", volinfo->volname);
+                gf_log(THIS->name, GF_LOG_ERROR, "%s", err_str);
+                goto out;
         }
 
 out:
@@ -259,6 +265,12 @@ gd_addbr_validate_replica_count (glusterd_volinfo_t *volinfo, int replica_count,
                         }
                 }
                 break;
+        case GF_CLUSTER_TYPE_DISPERSE:
+                snprintf (err_str, err_len, "Volume %s cannot be converted "
+                                            "from dispersed to replicated-"
+                                            "dispersed", volinfo->volname);
+                gf_log(THIS->name, GF_LOG_ERROR, "%s", err_str);
+                goto out;
         }
 out:
         return ret;
@@ -276,6 +288,7 @@ gd_rmbr_validate_replica_count (glusterd_volinfo_t *volinfo,
         switch (volinfo->type) {
         case GF_CLUSTER_TYPE_NONE:
         case GF_CLUSTER_TYPE_STRIPE:
+        case GF_CLUSTER_TYPE_DISPERSE:
                 snprintf (err_str, err_len,
                           "replica count (%d) option given for non replicate "
                           "volume %s", replica_count, volinfo->volname);
@@ -737,6 +750,8 @@ __glusterd_handle_remove_brick (rpcsvc_request_t *req)
                 strcpy (vol_type, "stripe");
         } else if (volinfo->type == GF_CLUSTER_TYPE_STRIPE_REPLICATE) {
                 strcpy (vol_type, "stripe-replicate");
+        } else if (volinfo->type == GF_CLUSTER_TYPE_DISPERSE) {
+                strcpy (vol_type, "disperse");
         } else {
                 strcpy (vol_type, "distribute");
         }