Heavy drive activity on standby firewall



  • Hi!  We have pfsense 2.2.3 configured in a HA 2 node failover cluster.  Each firewall has mirrored current-generation SSD's.  Recently, one of the SSD's in the standby firewall failed.  I enabled ssh and according to iostat, the standby firewall is writing anywhere from 30MB/s to 80 MB/s of data continuously to the drive.  (The primary firewall only writes about 2MB/s of data).  The internet connection at this site regularly has 150mb/s to 400+mb/s of bandwidth going through it.  Both firewalls are quad core xeons with 8 GB of ram.

    I have a two node cluster at another location and the standby firewall also has more disk writes than the primary, though it is not as extreme as this since the connection is not as busy.

    1.  Is high disk write activity normal on the standby firewall?

    2.  How do I go about reducing the disk writes, preferably without needing a reboot (this is in a busy production environment)?

    Thanks!



  • Activating the RAM disk options for /var and /tmp under System > Advanced on the Miscellaneous tab will reduce the amount of writes.  This is extremely effective on standby members of a two-node cluster on heavily-utilize internet connections!  Disk writes went from up to 100MB/s to nearly zero on the standby firewall in the HA carp cluster.  Since the firewalls are servers with plenty of ram, I set the ram disk sizes to 1 GB for /var and 500MB  for /tmp .


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