NEC iSM snapshots

Introduction

_images/necsnap.png

The NEC arrays snapshots driver allow multi-target block device replication and support the sync resync action which automates the Snapshot Volume and relink Link Volume. An opensvc service can thus easily use a snapshoted set of devices. This kind of services are often used for maintenance, pre-production, performance testing environments, where the source device set is used for production. The following documentation presents the configuration of such a service.

A service with only necismsnap sync resources can be defined to drive the snapshots of other servers, just for the benefit of centralized logging and scheduling.

Command set

sync resync
Unlink Link Volumes, resync Snapshot Volumes and relink Link Volumes.
sync resync --force
Bypass the sync_min_delay protection.

Status

up
The last resync occured less than 'sync_max_delay' minutes ago.
warn
  • The last resync occured more than 'sync_max_delay' minutes ago.
  • Snapshot Volumes or Link Volumes are in a unexpected state or not present in NEC array.

NEC iSM snapshots configuration

You have to create the Snapshot Volumes and Link Volumes manually once and link SV and LV to present them to the hosts. These properties can then be set in the service env file to ensure the snapshots will always be created and presented using those same properties. This is important to make the snapshot resync as transparent as possible to the operating system, and not to trigger device renames.

Examples

Resync a started service snapshots

# svcmgr -s iiststnec02 stop && svcmgr -s iiststnec02 sync resync && svcmgr -s iiststnec02 start

Resync a stopped service snapshots

# svcmgr -s iiststnec02 sync resync

2014-09-18 05:14:25,547 - iiststnec02.SYNC#1 - INFO - iSMsc_unlink -lv SOURCE_0001_LV00A6 -lvflg ld
2014-09-18 05:14:26,020 - iiststnec02.SYNC#1 - INFO - iSMsc_unlink:Info: iSM20030: iSMsc_unlink has normally terminated.

2014-09-18 05:14:26,052 - iiststnec02.SYNC#1 - INFO - iSMsc_unlink -lv SOURCE_0002_LV009E -lvflg ld
2014-09-18 05:14:26,375 - iiststnec02.SYNC#1 - INFO - iSMsc_unlink:Info: iSM20030: iSMsc_unlink has normally terminated.

2014-09-18 05:14:28,177 - iiststnec02.SYNC#1 - INFO - iSMsc_create -bv SOURCE_0001 -sv SOURCE_0001_SV006D -bvflg ld -svflg ld
2014-09-18 05:15:03,549 - iiststnec02.SYNC#1 - INFO - iSMsc_create:Info: iSM19010: iSMsc_create has normally terminated.
   BV:SOURCE_0001         LX
      Special File : -
   SV:SOURCE_0001_SV006D  LX
      Generation : -1
      Status     : snap/active [2014/09/18 05:15:04]

2014-09-18 05:15:03,590 - iiststnec02.SYNC#1 - INFO - iSMsc_create -bv SOURCE_0002 -sv SOURCE_0002_SV0055 -bvflg ld -svflg ld
2014-09-18 05:15:42,002 - iiststnec02.SYNC#1 - INFO - iSMsc_create:Info: iSM19010: iSMsc_create has normally terminated.
   BV:SOURCE_0002         LX
      Special File : -
   SV:SOURCE_0002_SV0055  LX
      Generation : -1
      Status     : snap/active [2014/09/18 05:15:42]

2014-09-18 05:18:43,426 - iiststnec02.SYNC#1 - INFO - iSMsc_link -lv SOURCE_0001_LV00A6 -sv SOURCE_0001_SV006D -lvflg ld -svflg ld
2014-09-18 05:18:43,453 - iiststnec02.SYNC#1 - INFO - iSMsc_link:Info: iSM20020: iSMsc_link has normally terminated.

2014-09-18 05:18:43,483 - iiststnec02.SYNC#1 - INFO - iSMsc_link -lv SOURCE_0002_LV009E -sv SOURCE_0002_SV0055 -lvflg ld -svflg ld
2014-09-18 05:18:43,510 - iiststnec02.SYNC#1 - INFO - iSMsc_link:Info: iSM20020: iSMsc_link has normally terminated.