11gR2 Clusterware Startup Order


IMG_20150122_195929

OLR – Is the first file to be read and opened. This file is local and this file contains information regarding where the voting disk, ASM spfile, instance spfile are stored.

VOTING DISK – This is the second file to be opened and read, this is dependent on only OLR being accessible. CSSD joins the cluster to do so it must access voting file stored in asm Disk Group(DG).and asm depends upon CSSD being available.

so what it does is CSSD read OLR and find out the location of voting disk in asm DG. and starts reading the header of ASM DG and get info about voting disk. so now voting disk is available without having to start ASM instance really.

3. In this step OHASD start ASM instance by first reading OLR and pulling info about ASM spfile and then later by scanning the header of ASM DG we read asm spfile and now we can start ASM instance.

4. since we have mounted DG now so OCR is available now. CRSD reads OCR file and make resources available in the cluster.

ASM starts after CSSD or ASM does not start if CSSD is offline (i.e voting file missing)

So, if ASM already started, ASM does not depend on OCR or OLR to be online. ASM depends on CSSD (Votedisk) to be online.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s