Instant Image Cheat Sheet
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
Word | Meaning |
---|---|
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?
Version | Packages |
---|---|
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
- If Veritas Volume Manager installed
- 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.