[libvirt] [PATCH v4] virsh: Add more human-friendly output of domblkstat command

Peter Krempa pkrempa at redhat.com
Thu Sep 8 14:11:10 UTC 2011


Users of virsh complain that output of the domblkstat command
is not intuitive enough. This patch adds explanation of fields
returned by this command to the help section for domblkstat and
the man page of virsh. Also a switch --human is added for
domblkstat that prints the fields with more descriptive
texts.

https://bugzilla.redhat.com/show_bug.cgi?id=731656

Changes to v3:
- Add units to duration values
- Add missing write doc/stranslation
- Add translation from new api names to legacy names used in previous
  versions in virsh

Changes to v2:
- Modify for new fields in virDomainBlockStatsFlags

Changes to v1:
- Rebase to current head
---
 tools/virsh.c   |  126 +++++++++++++++++++++++++++++++++++++++++++++++-------
 tools/virsh.pod |   15 ++++++-
 2 files changed, 123 insertions(+), 18 deletions(-)

diff --git a/tools/virsh.c b/tools/virsh.c
index cf3e816..f281d7a 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -1054,16 +1054,53 @@ cleanup:
  */
 static const vshCmdInfo info_domblkstat[] = {
     {"help", N_("get device block stats for a domain")},
-    {"desc", N_("Get device block stats for a running domain.")},
+    {"desc", N_("Get device block stats for a running domain.\n\n"
+                "    Explanation of fields:\n"
+                "      rd_req            - count of read operations\n"
+                "      rd_bytes          - count of read bytes\n"
+                "      rd_total_times    - total time read operations took (ns)\n"
+                "      wr_req            - count of write operations\n"
+                "      wr_bytes          - count of written bytes\n"
+                "      wr_total_times    - total time write operations took (ns)\n"
+                "      flush_operations  - count of flush operations\n"
+                "      flush_total_times - total time flush operations took (ns)\n"
+                "      errs              - error count")},
     {NULL,NULL}
 };

 static const vshCmdOptDef opts_domblkstat[] = {
     {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
     {"device", VSH_OT_DATA, VSH_OFLAG_REQ, N_("block device")},
+    {"human",  VSH_OT_BOOL, 0, N_("print a more human readable output")},
     {NULL, 0, 0, NULL}
 };

+struct _domblkstat_translate {
+    const char *from;
+    const char *to;
+};
+
+/* translations into a more human readable form */
+static const struct _domblkstat_translate domblkstat_human[] = {
+    { VIR_DOMAIN_BLOCK_STATS_READ_BYTES,        N_("number of read bytes:      ") }, /* 0 */
+    { VIR_DOMAIN_BLOCK_STATS_READ_REQ,          N_("number of read operations: ") }, /* 1 */
+    { VIR_DOMAIN_BLOCK_STATS_READ_TOTAL_TIMES,  N_("total duration of reads:   ") }, /* 2 */
+    { VIR_DOMAIN_BLOCK_STATS_WRITE_BYTES,       N_("number of bytes written:   ") }, /* 3 */
+    { VIR_DOMAIN_BLOCK_STATS_WRITE_REQ,         N_("number of write operations:") }, /* 4 */
+    { VIR_DOMAIN_BLOCK_STATS_WRITE_TOTAL_TIMES, N_("total duration of writes:  ") }, /* 5 */
+    { VIR_DOMAIN_BLOCK_STATS_FLUSH_REQ,         N_("number of flush operations:") }, /* 6 */
+    { VIR_DOMAIN_BLOCK_STATS_FLUSH_TOTAL_TIMES, N_("total duration of flushes: ") }, /* 7 */
+    { VIR_DOMAIN_BLOCK_STATS_ERRS,              N_("error count:               ") }, /* 8 */
+    { NULL, NULL }
+};
+
+/* translations into legacy field values used in previous versions */
+static const struct _domblkstat_translate domblkstat_legacy[] = {
+    { VIR_DOMAIN_BLOCK_STATS_READ_REQ,  "rd_req"},
+    { VIR_DOMAIN_BLOCK_STATS_WRITE_REQ, "wr_req"},
+    { NULL, NULL }
+};
+
 static bool
 cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
 {
@@ -1071,8 +1108,11 @@ cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
     const char *name = NULL, *device = NULL;
     struct _virDomainBlockStats stats;
     virTypedParameterPtr params = NULL;
+    const char *field_name = NULL;
+    int j = 0;
     int rc, nparams = 0;
     bool ret = false;
+    bool human = vshCommandOptBool(cmd, "human"); /* enable human readable output */

     if (!vshConnectionUsability (ctl, ctl->conn))
         return false;
@@ -1104,20 +1144,41 @@ cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
                 goto cleanup;
             }

-            if (stats.rd_req >= 0)
-                vshPrint (ctl, "%s rd_req %lld\n", device, stats.rd_req);
+            if (human) {
+                /* human friendly output */
+                vshPrint(ctl, N_("Device: %s\n"), device);
+
+                if (stats.rd_req >= 0)
+                    vshPrint (ctl, "%s %lld\n", domblkstat_human[1].to, stats.rd_req);
+
+                if (stats.rd_bytes >= 0)
+                    vshPrint (ctl, "%s %lld\n", domblkstat_human[0].to, stats.rd_bytes);
+
+                if (stats.wr_req >= 0)
+                    vshPrint (ctl, "%s %lld\n", domblkstat_human[4].to, stats.wr_req);
+
+                if (stats.wr_bytes >= 0)
+                    vshPrint (ctl, "%s %lld\n", domblkstat_human[3].to, stats.wr_bytes);
+
+                if (stats.errs >= 0)
+                    vshPrint (ctl, "%s %lld\n", domblkstat_human[8].to, stats.errs);
+            } else {
+
+                if (stats.rd_req >= 0)
+                    vshPrint (ctl, "%s rd_req %lld\n", device, stats.rd_req);

-            if (stats.rd_bytes >= 0)
-                vshPrint (ctl, "%s rd_bytes %lld\n", device, stats.rd_bytes);
+                if (stats.rd_bytes >= 0)
+                    vshPrint (ctl, "%s rd_bytes %lld\n", device, stats.rd_bytes);

-            if (stats.wr_req >= 0)
-                vshPrint (ctl, "%s wr_req %lld\n", device, stats.wr_req);
+                if (stats.wr_req >= 0)
+                    vshPrint (ctl, "%s wr_req %lld\n", device, stats.wr_req);

-            if (stats.wr_bytes >= 0)
-                vshPrint (ctl, "%s wr_bytes %lld\n", device, stats.wr_bytes);
+                if (stats.wr_bytes >= 0)
+                    vshPrint (ctl, "%s wr_bytes %lld\n", device, stats.wr_bytes);

-            if (stats.errs >= 0)
-                vshPrint (ctl, "%s errs %lld\n", device, stats.errs);
+                if (stats.errs >= 0)
+                    vshPrint (ctl, "%s errs %lld\n", device, stats.errs);
+            }
         }
     } else {
         params = vshMalloc(ctl, sizeof(*params) * nparams);
@@ -1129,32 +1190,63 @@ cmdDomblkstat (vshControl *ctl, const vshCmd *cmd)
         }

         int i;
+
+        /* set for prettier output */
+        if (human) {
+            vshPrint(ctl, N_("Device: %s\n"), device);
+            device = "";
+        }
+
         /* XXX: The output sequence will be different. */
         for (i = 0; i < nparams; i++) {
+            /* translate messages into a human readable form, if requested */
+            field_name = NULL;
+
+            if (human)
+                for (j = 0; domblkstat_human[j].from != NULL; j++)
+                    if (STREQ(params[i].field, domblkstat_human[j].from)) {
+                        field_name = domblkstat_human[j].to;
+
+                        break;
+                    }
+
+            /* translate new QEmu style field names into legacy names used by virsh */
+            if (!field_name)
+                for (j = 0; domblkstat_legacy[j].from != NULL; j++)
+                    if (STREQ(params[i].field, domblkstat_legacy[j].from)) {
+                        field_name = domblkstat_legacy[j].to;
+
+                        break;
+                    }
+
+            /* translation not found, stick with the default field name */
+            if (!field_name)
+                field_name = params[i].field;
+
             switch(params[i].type) {
             case VIR_TYPED_PARAM_INT:
                 vshPrint (ctl, "%s %s %d\n", device,
-                          params[i].field, params[i].value.i);
+                          field_name, params[i].value.i);
                 break;
             case VIR_TYPED_PARAM_UINT:
                 vshPrint (ctl, "%s %s %u\n", device,
-                          params[i].field, params[i].value.ui);
+                          field_name, params[i].value.ui);
                 break;
             case VIR_TYPED_PARAM_LLONG:
                 vshPrint (ctl, "%s %s %lld\n", device,
-                          params[i].field, params[i].value.l);
+                          field_name, params[i].value.l);
                 break;
             case VIR_TYPED_PARAM_ULLONG:
                 vshPrint (ctl, "%s %s %llu\n", device,
-                          params[i].field, params[i].value.ul);
+                          field_name, params[i].value.ul);
                 break;
             case VIR_TYPED_PARAM_DOUBLE:
                 vshPrint (ctl, "%s %s %f\n", device,
-                          params[i].field, params[i].value.d);
+                          field_name, params[i].value.d);
                 break;
             case VIR_TYPED_PARAM_BOOLEAN:
                 vshPrint (ctl, "%s %s %s\n", device,
-                          params[i].field, params[i].value.b ? _("yes") : _("no"));
+                          field_name, params[i].value.b ? _("yes") : _("no"));
                 break;
             default:
                 vshError(ctl, _("unimplemented block statistics parameter type"));
diff --git a/tools/virsh.pod b/tools/virsh.pod
index e82567d..a2f87cd 100644
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -501,13 +501,26 @@ be lost once the guest stops running, but the snapshot contents still
 exist, and a new domain with the same name and UUID can restore the
 snapshot metadata with B<snapshot-create>.

-=item B<domblkstat> I<domain> I<block-device>
+=item B<domblkstat> I<domain> I<block-device> [I<--human>]

 Get device block stats for a running domain.  A I<block-device> corresponds
 to a unique target name (<target dev='name'/>) or source file (<source
 file='name'/>) for one of the disk devices attached to I<domain> (see
 also B<domblklist> for listing these names).

+Use I<--human> for a more human readable output.
+
+B<Explanation of fields:>
+  rd_req            - count of read operations
+  rd_bytes          - count of read bytes
+  rd_total_times    - total time read operations took (ns)
+  wr_req            - count of write operations
+  wr_bytes          - count of written bytes
+  wr_total_times    - total time write operations took (ns)
+  flush_operations  - count of flush operations
+  flush_total_times - total time flush operations took (ns)
+  errs              - error count
+
 =item B<domifstat> I<domain> I<interface-device>

 Get network interface stats for a running domain.
-- 
1.7.3.4




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