Backup speed would degrade over time. Slower after several days. slow performance

  • 3633404
  • 10-Apr-2007
  • 16-Mar-2012

Environment

NetWare 6.5
support pak 5
backup and restore using Arcserve tape software 11.1r

Situation

Backup speed would degrade over time. Slower after several days. slow performance

Resolution

Reduced these settings to the default of 100000

Additional Information

The server being backed up had only 2 gig of ram. Two nss tuning parms had been set too high for the amount of ram that the server contained.

nss /namecachesize=500000
nss /closedfilecachesize=500000

These settings would cause nss.nlm to take over 700mg of the server's ram. Almost half. This would especially be true when backing up very large volumes. In this case the volumes were over 500gig in size. Nss will not release this memory until the server is getting low on memory. Such was not the case here. The server still had enough memory to operate, but the nss cache was so low, that performance suffered. The nss.nlm had taken the memory from nss cache. This can be seen when loading the seg.nlm. This will show the top memory consuming nlms on the servers. See KB 3341011 -

Formerly known as TID# 10100888