This article explains how to set up an appropriate syncer rate speed that is responsible for the synchronization of the shared “pbdata” storage between both QFabric Primary and Backup director devices. To avoid GFS corruption it is recommended to set the syncer rate to 25MB.

After or during activities like NSSU and DG replacement, the syncer rate needs to be checked and set as 25MB on both DGs from the default value of 1500MB or any other different value present on the DGs.

The following steps to be performed on both Primary and Backup DGs:

1. Log in to DG shell and verify the current DRBD syncer rate.

   [root@dg0 ~]# drbdsetup /dev/drbd0 show | grep -B1 rate
   syncer {
   rate 1536000k; # bytes/second

   Note: The default syncer rate is 1500MB/s or 1536000KB/s.

2. Permanently set the syncer rate to 25MB/s by updating the DRBD configuration file.

   root@dg1 ~]# sed -i 's/rate 1500M/rate 25M/g' /etc/drbd.conf

   Note: While changing the value make sure the configured value [from step 1] is replaced [here 1500M]

3. Confirm the configuration syncer rate has been changed accordingly.

   [root@dg1 ~]# grep syncer /etc/drbd.conf
   syncer { rate 25M; }

4. Adjust the active syncer rate accordingly based on the changed configuration file value.

   [root@dg1 ~]# drbdadm adjust pb_drbddata

5. Confirm the active syncer rate speed has been accordingly changed to 25MB/s.

   [root@dg1 ~]# drbdsetup /dev/drbd0 show | grep -B1 rate
   syncer {
   rate 25600k; # bytes/second