Instant Image Cheat Sheet

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Point-In-Time Copy (aka Instant Image) copies of raw partitions (virtual or physical). The software is similar to the snap-shot feature found in Veritas Volume Manager. What it does not do is act as a mirror. Simply put, the software takes a picture, and then tracks any changes made since the copy is made through the use of a bitmap. The bitmap allows the user to sync data in any direction.

GLOSSARY

WordMeaning
Volume A raw device (don't confuse this with a Veritas volume).
Master Volume Original location of data Critical Online work can be occurring on this.
Shadow Volume Point-In-Time image of the master
Bitmap Record which tracks difference between the Master and Shadow Volumes. In versions BEFORE 3.x, the bitmap MAY be a regular file, but there is a bug that could potentially cause data loss if the bitmap is made on a file. It is best to use a raw slice or Veritas volume to house the bitmap. In Instant Image 3.0 and above, bitmaps must be raw devices (either a slice or a metadevice or a Veritas volume).
Volume Set Master, Shadow, and BitMap
Independent Shadow full copy (can even be moved to another server later)
Dependent Shadow no copy occurs to the shadow. The master volume must remain accessible in order to access the shadow.

WHAT VERSION?

# pkginfo -x SUNWii SUNWiir

NOTE: One of the above packges will error the other won't. The package names have changed between the 2.x and 3.x versions.

WHAT PACKAGES INSTALLED?

VersionPackages
2.x SUNWscm SUNWspsv SUNWspuni SUNWii (minimal config, there are others)
3.0 SUNWscmr SUNWscmu SUNWspsvr SUNWspsvu SUNWii
3.1 & 3.2 SUNWscmr SUNWscmu SUNWspsvr SUNWspsvu SUNWiir SUNWiiu

WHAT PROCESSES?

nskernd

WHAT DRIVERS LOADED?

#  modinfo | egrep "(nskern | sdbc | nsctl | ii | iidev| sv)"

WHAT CONFIGURATION?

  • Get the state of the Volume Sets: 
    # /usr/opt/SUNWesm/sbin/iiadm -i all
  • Status of the raw partitions in use:
    • If Veritas Volume Manager installed 
      # vxprint -ht
    • If Solsrice DiskSuite installed: 
      # metastat
    • If no disk managemant software used: 
      # prtvtoc
  • You may want to know how the drivers are configured:
    VersionFiles / Output
    2.x Get these files /etc/opt/SUNWspsv/sv.cf /usr/kernel/drv/ii.conf /etc/opt/SUNWscm/bitmapfs.cf
    3.x Get these outputs /usr/opt/SUNWscm/sbin/dscfg -l /usr/opt/SUNWesm/SUNWspsv/sbin/svadm

    USEFUL COMMANDS

    CommandComments
    /usr/opt/SUNWesm/sbin/iiadm This command manipulates the II sets. Once a set is created, you ALWAYS make a transaction on the shadow device, as it represents the set you are manipulating.
    /usr/opt/SUNWscm/sbin/dscfg This command manipulates the data services configuration location. With the -l option, it prints out the configuration.
    /usr/opt/SUNWesm/SUNWsvsp/svadm Manipulates the sv driver layer. You can view the objects in the driver stack with this command.