# very slow drbd replication

**URL:** <https://forums.suse.com/t/very-slow-drbd-replication/30241>\
**Category:** SLES High Availability Extension\
**Created:** [August 30, 2017, 4:01pm UTC](https://forums.suse.com/t/very-slow-drbd-replication/30241 "2017-08-30T16:01:00Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sharfuddin](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@sharfuddin](https://forums.suse.com/u/sharfuddin)\
**Post date:** [August 30, 2017, 4:01pm UTC](https://forums.suse.com/t/very-slow-drbd-replication/30241/1 "2017-08-30T16:01:00Z")

</div>

SLES 12 SP2 + online updates.

Its a 1 TB volume with XFS file system and both the nodes are connected via 1 Gbps network. DRBD replication started 41 hours before but it just reached 8.78 %.

```auto
drbdsetup status oracle --verbose --statistics
oracle node-id:1 role:Primary suspended:no
    write-ordering:flush
  volume:0 minor:0 disk:UpToDate
      size:1904549052 read:515556707 written:13288947 al-writes:6734 bm-writes:0
      upper-pending:0 lower-pending:0 al-suspended:no blocked:no
  prdnode2 node-id:0 connection:Connected role:Secondary congested:no
    volume:0 replication:SyncSource peer-disk:Inconsistent done:8.78
        resync-suspended:no
        received:0 sent:176786480 out-of-sync:1737341808 pending:0 unacked:0
```

Why replication is so slow ?

Also would you advise me to run the following command on SyncTarget node: [code]

```
    drbdadm disk-options --c-plan-ahead=0 --resync-rate=110M oracle [/code]

```

and then later on edit the resource file to add the following: [code]

```
 disk { resync-rate 100M; } [/code]

```

current configuration:  
global\_common.conf

```auto
global { usage-count no;}

common {
	handlers { fence-peer "/usr/lib/drbd/crm-fence-peer.sh"; after-resync-target "/usr/lib/drbd/crm-unfence-peer.sh"; }

	startup { wfc-timeout 0; degr-wfc-timeout 120; }

	disk { on-io-error detach; al-extents 3389; }
	
	net { after-sb-0pri discard-zero-changes; after-sb-1pri discard-secondary; max-buffers 8000;                 
    		max-epoch-size 8000; sndbuf-size 0; verify-alg md5; ping-int 2; ping-timeout 2; connect-int 2;
    		timeout 5; ko-count 5; }
}
```

resource file:  
oracle.res

```auto
resource oracle {
   device /dev/drbd_r0 minor 0;
   meta-disk internal;

   on node1 { disk "/dev/sdb2"; address 10.1.1.1:7780; }  

   on node2 { disk "/dev/sdb2"; address 10.1.1.2:7780; }
   
}
```

---

<div class="post-metadata">

**Author:** ![Automatic\_Reply](https://avatars.discourse-cdn.com/v4/letter/a/ecb155/32.png) [@Automatic\_Reply](https://forums.suse.com/u/Automatic_Reply)\
**Post date:** [September 4, 2017, 7:30am UTC](https://forums.suse.com/t/very-slow-drbd-replication/30241/2 "2017-09-04T07:30:15Z")

</div>

sharfuddin,

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