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Showing posts from January, 2017

VXASSIST with Examples

vxassist – Syntax with examples /usr/sbin/vxassist – Finds space for and creates volumes – Performs volume conversion – Adds mirrors and logs to existing volumes – Extends and shrinks existing volumes – Migrates data from a specified set of disks – Provides facilities for the online backup of existing volumes Tasks & Switches: Check the maximum size a volume could be created vxassist [-g diskgroup] maxsize Check the maximum size a volume can grow vxassist [-g diskgroup] maxgrow volume-name [attrs...] Create volume vxassist [-g diskgroup] [-U usetype] [-b] make volume-name {len|maxsize=<size>} [layout=layout_method] [attrs...] Add logs to volume vxassist [-g diskgroup][-b] addlog volume-name [attrs...] Resize volumes growto vxassist [-g diskgroup] growto volume-name new-length [attrs...] growby vxassist [-g diskgroup] growby volume-name length-change [attrs...] Shrinkto vxassist [-g diskgroup][-f] shrinkto volume-name new-length [attrs...] s

Measure and Troubleshoot Linux Memory Resource Usage

Tracking down physical memory usage (RAM + swap) and identifying amount of memory needed for current workload on a Debian Linux server.  Install Performance Monitoring Tools Install sysstat, if not yet installed: # apt-get update && apt-get install sysstat For RHEL/CentOS, do the following: # yum install -y sysstat The sysstat package contains the  sar  system performance tool which we’re going to use today. Make sure that sar is enabled in  /etc/default/sysstat . If not enabled, do it. You may also want to change the history value in  /etc/sysstat/sysstat  to something different than 7 days: HISTORY=60 Note that if value is greater than 28, then log files will be kept in multiple directories, one for each month. By default sysstat will collect data every 10 minutes. You can change this by modifying the cronjob  /etc/cron.d/sysstat . Finally, restart the service: # service sysstat restart Measure Memory Usage Memory Usage with  free The  free  comm