Learning ASM: Installing a Database

REVIEW

In my previous posts I logged my experience installing the 11gR2 Grid Infrastructure and getting familiar with ASM. At this point I have a working ASM instance, as well as Oracle High Availability and Cluster Services running, and an ACFS file system, for kicks.

My ASM Disk groups available are:

ASMDATA - Where my database files will go
FRA - Where my Flash Recovery Area will go
FS - Hosts my ACFS partition, where database files will go that wouldn't normally go on an ASM disk.

My goal in this post is not to reproduce the steps in the manual, but to record my own notes of things that are interesting or troublesome along the way. I'm following the steps as documented in the Database Installation Guide 11g Release 2 (11.2) for Linux.

I already configured the kernel parameters and made sure the necessary libraries were installed, and I already created a separate user account (oracle11r2) to host all my 11.2.0.1 files. ASM was installed under the user oragrid, to keep the installations distinct.

HERE WE GO:

First note of "something new" in the install guide is the enhanced Secure Configuration option. I'm a security nut, so I'll be taking this option, especially since it gives more opportunity to learn.

Files are unzipped, X DISPLAY is verified, let's do this...

$ ./runInstaller
You do not have sufficient permissions to access the inventory '/u01/app/oraInventory/orainstRoot.sh.ASMbackup'...

Hit the first issue sooner than I thought.

$ ls /u01/app/oraInventory/orainstRoot.sh.ASMbackup
-rwxr-x--- 1 oragrid oinstall 1623 Sep 8 23:08 /u01/app/oraInventory/orainstRoot.sh.ASMbackup

This one's my own fault. I made a backup of the ASM root.sh script after the ASM install. It does not have group write permissions. Apparently runInstaller checks to see if all directories are accessible, not just specific directories that it will use. I changed the group write permission on the directory, since I don't expect it to be touched anyway. Now runInstaller is able to move onto the prerequisites, and we get the spiffy new 11gR2 Installer GUI.

Note: I'm posting this blog on a different machine, so I'm not taking screen shots as I go. There may be typos since I'm re-typing instead of copy-and-pasting. If you find one, please let me know so I can fix the post.


CONFIGURE SECURITY OPTIONS

I'm not setting this up for a connection to MetaLink so I uncheck that, and leave the email blank for now. I get a dialog box letting me know that Uncle Larry won't be looking over my shoulder to inform me of security updates now. That's fine with me for this project.

INSTALLATION OPTION

I'm selecting "Create and configure a database". I can always create another later for the DBCA experience. I'm more curious what this installer does on autopilot.

SYSTEM CLASS

Even though I am using a desktop class machine, in power, I have been treating it as a server, in function. ASM features are only available under this option, so I'm choosing "Server Class" here.

GRID OPTIONS

While I would really like to play with RAC features here at home, I know I don't have the infrastructure for it, so I won't risk confusing myself with a single-node RAC-ish installation. I'm sticking with "Single instance database installation" for this option.

INSTALL TYPE

The whole point of this exercise is to learn ASM, so I need to choose "Advanced Install" here, for the opportunity to install on ASM. (Of course I could start with non-ASM and convert to ASM as another exercise, but I have not layed out my partitions to do so).

PRODUCT LANGUAGES

Self-explanatory.

DATABASE EDITION

Enterprise, Standard, or Standard Edition ONE? Here is where licensing would come into play. Since this is under an OTN "get familiar, non-production" license, I'm going with EE with all the options, including Database Vault.

INSTALLATION LOCATION

Oracle Base: /u01/app/oracle11r2
Software Location: /u01/app/oracle11r2/product/11.2.0/dbhome_1

I'll take the defaults here, since I expect most places I go will install things in the default layouts. If they don't I'll be able to spot the difference right away.

Since the Oracle Inventory was created when I installed Grid Infrastructure, I'm not given that option here. I like this. I have enough ways to shoot myself in the foot. If Oracle can prevent me from a confusing multiple-inventory situation, I appreciate it.

CONFIGURATION TYPE

For now I'm interested in "General Purpose / Transaction Processing".

DATABASE IDENTIFIERS

Global Database Name: ora11r2.localdomain
SID: ora11r2

Normally I would change the localdomain to something appropriate, but I'm not worried about that for this machine. I left it at that default in the Infrastructure install, so that's what the Listener is expecting. I'll leave localdomain here, too.

CONFIGURATION OPTIONS

MEMORY

Enable Auto Memory Management. Yes, please. I'll start with the default 40% of memory (604MB in my case). In the real world I would do some capacity planning beforehand and size this based on a more educated guess, then tune as needed over time.

CHARACTER SETS

I'm taking the default here. I'll play with UNICODE in another instance, another time.

SECURITY

Assert All New Security Settings. I'm not upgrading an older database, and I am interested in learning new features, so I'll stick to the default here, which is yes... use the new security settings.

SAMPLE SCHEMAS

Good, the default is unchecked. I like that. I'll check it here, but for an application database I prefer to not have the sample schemas - less to secure or clean up.

MANAGEMENT OPTIONS

I don't have a Grid Control installation, or agent here, so that's grayed out. That leaves DB Control, which is fine. I'm skipping email notifications for now.

DATABASE STORAGE

Here's where we get interesting. ASM is selected by default. I put in the password I created for ASMSNMP during the ASM installation. There were fewer options than I expected here.

AUTOMATED BACKUPS

I haven't allocated space for multiple backups, so I'll leave the automated backups disabled. 11gR2 RMAN features and backup strategies will be an exercise for another time.

ASM DISK GROUP

Here is the option I expected to see earlier. My database files will go on ASMDATA.

SCHEMA PASSWORDS

Self-explanatory.

OPERATING SYSTEM GROUPS

Default.

PREREQUISITE CHECKS

I ran into the same prerequisite failure here on pdksh that I did on the Infrastructure installation. I know I have ksh available, even if it is not pdksh, so I'm Ignoring this issue and continuing. I wouldn't ignore this on a system that needs to remain stable.

SUMMARY

I'll save a response file (ora11r2.rsp) to use or review later.

INSTALL PRODUCT

Now we wait while OUI does it's thing.

For status freaks like me, who like to know more than just watching the checklist of what's been done so far, the Details window lets me watch the install log and scroll back through the history without 'tail'ing it in a separate window. Nice touch.

I didn't keep a timer, but for a full EE install on an underpowered machine, the install process moves along pretty well. I'm eager for the opportunity to see it on some bigger iron.

DBCA, on the other hand, is really pokey, but I don't blame DBCA. Now we're hitting the expected performance problems of my machine.

My system is CPU-bound. CPU is pegged at 100% for extended periods. No surprise on this box.
Memory is in good shape - hovering around 30% used.
top shows the database being created using more resources than the ASM database.
iostat DOES show activity spread out across the various partitions representing my ASM disks.

At this point I am seeing ASM get its first workout and I see the load spreading across what would normally be multiple devices. If you didn't read my first post on learning ASM, you missed the fact that I'm simulating 10 disks using 10 partitions on a single physical drive. High Speed anything was never a goal in this exercise.

dbca finished, root.sh run.

The root.sh script complained about dbhome, oraenv, and coraenv already existing in /usr/local/bin. I made backup copies of these and allowed root.sh to overwrite them. diff showed the new files identical to the old, and permissions are such that oragrid won't have a problem, so it appears to be OK to just overwrite what the Grid Installation installed.

FINISH

This screen simply reminds us of the URL for DB Control. Closed the installer.


TEST DRIVE

Start FireFox, browse to the EM URL, accept the security certificate, and ... waiting ...

DB Control reports the database components are unavailable.
Attempting to connect via sqlplus also fails, with a TNS error.

Clearly, something is misconfigured at this point. Before banging my head and making things worse, I turn the page to the Post-Installation Tasks.

I reboot just to clean things up a bit, and start a piece at a time. I notice my network interface failed on boot - that explains a number of things. I corrected the networking issue and lsnrctl status under oragrid responded as expected.

I login as oracle11r2, set ORACLE_HOME and ORACLE_SID as needed.

Now sqlplus works, and I see the database is already up. This is odd, t me, since the startup flag in /etc/oratab for this instance is 'N'. Oracle Restart is coming into play here. The startup configuration I already did for ASM laid the groundwork for the new instance "ora11r2" being started automatically.

$ ./emctl start dbconsole

DB Console appeared to come up, but crashed upon first login attempt.

I set up the .bash_profile for oracle11r2 to have the proper ORACLE_HOME and ORACLE_SID, created a DBA ID for myself in the database (so I didn't have to login as SYS), then I restarted the DB Console.

When DB Console is running, it appears to be the big CPU hog on this machine. CPU and disk I/O is moderate and acceptable when DB Console is not running.

POST_INSTALLATION TASKS

I followed the relevant steps for post-installation tasks that applied to my instance.

Via DB Console, I found my way to the Flash Recovery Area setting. I changed this from +ASMDATA to +FRA and increased the size to make use of more of the ASM disk group allocated to flash recovery.

THE END, AND THE BEGINNING
At this point Oracle 11g Release 2 is up and running on a tiny machine, with ASM.
Let the learning continue...

Learning ASM: Part 1

Oracle's ASM (Automatic Storage Management) may well be one of the most significant additions to the Oracle database, beginning in 10g, and becomes more interesting in 11g Release 2. I wanted to learn it at home, before I run into it at a client, and because it is extremely interesting technology. This post logs my experiences setting it up for the first time. This may become my personal HOWTO reference on the topic - expect to see extreme detail as we get into it.

About ASM:

If you are unfamiliar with ASM, it is storage management software that comes with the database. It provides the performance of using RAW devices without the need to manage an storage volume through the operating system or a logical volume manager. For the DBA this translates into more direct control over the storage and more efficiency. For the business, this may translate into reduced costs, if it saves on a license for 3rd-party volume management.

You provide ASM with a pool of storage devices, and then tell ASM how to divide that up logically. You can add or remove devices as needed, without interrupting the database, and ASM will automatically spread your data and load across all the devices. This can be a viable substitute for RAID systems, eliminating another layer of software and hardware. (However, if you have a solid RAID strategy in place already, you can use ASM for managing the volumes, and still let the RAID handle redundancy.)

In 11g Release 2 it gets even more interesting with the introduction of ASM Cluster File System (ACFS). ACFS provides an operating-system-usable file system running on top of Oracle ASM. "Why would I do that?" to further simplify the life of the DBA. In 10g, ASM could not be used for files outside the database, such as binaries, log files, etc. With ACFS all of those files can also be moved into ASM storage. You can set up a cluster of machines running ASM and it can pool storage across the entire cluster, and present it to Oracle and/or the filesystem as if it were a big pool of local storage.


The setup:

I'm slow to adopt new hardware at home, so to make this more interesting I am going to be exploring this on a single-CPU Celeron machine, circa 2005. I don't expect speed or performance. I just want to learn the syntax and management. And yes, Oracle will run on this... just don't expect to do much with it besides self-education. This is a home-class machine, so I have 2 hard drives. One with some older data in a Windows partition I want to save, The other a larger drive with a Windows partition, a Linux partition, and a bunch of extra space to play with.

Hardware: Single CPU Celeron
RAM 1.5 GB
Storage: 1 250GB Hard Drive, in multiple partitions.

ASM is designed to pool storage across multiple devices. I don't have multiple devices, but can simulate that for the sake of education by using multiple partitions. I fully expect this to perform slowly since these are on the same physical device.

FIRST STEP: SET UP PARTITIONS AND INSTALL LINUX

I'm going with CentOS 5.3, which is equivalent to RHEL 5. I had previously installed 11g Release 1 on this machine, so I know the Oracle Database will run, at least.

Here is my partition layout, yours may be different.
/dev/hda
/dev/hda1 Windows Partition NTFS 102398 MB
/dev/hda5 / ext3 23454 MB
/dev/hda6-15 10 virtual physical devices LVM PV 10236 MB each
/dev/hda16 swap swap 10236 MB


In a real system I wouldn't lump root, /home, etc all on the same partition, but for this exercise I'm going simple. I made my partitions roughly 10GB in size for simplicity later.

After this I finished the Linux installation, and made sure all the required packages for the Oracle Database were installed, as directed in the 11gR2 Installation Guide for Linux.

NEXT STEP: CONFIGURE LINUX

• Post-install configuration included setting the following options:
• Opened TCP port 1521 in the firewall.
• SELinux Setting set to Permissive
• Created a non-root user (bbontrag, in my case) to login as
• Configured Linux to connect to my local network, and verified Internet access
  
• Verified that boot parameters are only attaching drives 0 and 4 (/ and swap, or /dev/hda1 and /dev/hda5). This was verified in /boot/grub/grub.conf and by viewing the partitions in CentOS Logical Volume Management.
• Rebooted at this point to ensure networking was fully operational
  
• Used the Package Manager to verify all required packages from the Oracle Install Guide.
• On a normal development or production system I would install O/S patches at this point. For this machine, I am skipping that step, so I can practice patching AFTER a database is installed. (But that's another post).

NEXT STEP: PREPARE TO INSTALL Oracle 11gR2

In reviewing the documentation for 11gR2 I found this little nugget... "Oracle Database 11g Release 2 introduces the Grid Infrastructure installation. For single instance databases, the grid infrastructure includes Automatic Storage Management, the listener, and Oracle Restart."..."If you want to use grid infrastructure for a standalone server, then you must install the oracle software from the grid infrastructure media before you install the database." In 11gR1 ASM was included on the Database Install media. In this release it is separate.
(What's New in Oracle Database 11g )

(If you are following this as a HOWTO, hold off on this section until AFTER Oracle Grid Infrastructure is installed in the next step. I got ahead fo myself - don't get yourself into the same trouble I did.) I prepared to install the Oracle 11gR2 software according to according to the Quick Install Guide.

• Checked installed packages
• Setup groups and users, since this was the first install of Oracle software
• Set kernel parameters and other configuration parameters
  
• I created oracle11r2 instead of oracle as the oracle User Id, to allow a future install of previous versions to practice upgrades.
• I had trouble with the default profile script trying to use ksh as the default shell for oracle11r2. I changed the default shell to bash and it worked fine

At this point I copied the install media onto the server, but did not install the database yet.

INFRASTRUCTURE INSTALL: ASM LIBRARIES

I installed ASM according to the Oracle Grid Infrastructure Install Guide.

• created user oragrid, where the instructions called for "oracle". This will allow me to understand the difference between grid infrastructure files and normal database files. (I may get into trouble by doing this... we'll see). Note: after creating new users I had to logout and log back in, to restart the X server. New users did not have authority to run X apps, such as the OUI, so this was my workaround.
  
• Since permissions for oracle were already set on /u01/app I reset ownership to be what the Infrastructure guide called for.
• Since my installation is not registered with the Unbreakable Linux Network, I had the joy of installing ASMLIB manually, which is a set of Linux libraries for interacting with ASM. The steps are documented in the Install Guide. Follow them carefully, On my first attempt I downloaded the wrong version. On my second attempt I still missed the oraclasm driver for my kernel. There are 3 packages to install, if the install guide is not clear on that.
  
• Install the oracleasm package first, then the other packages. The oracleasmlib package depends on it.

INFRASTRUCTURE INSTALL: CONFIGURE ASM

• Once the packages successfully installed I ran oracleasm configure -i as instructed.
• The install guide is not clear what to enter here. I used user=oragrid, group=oinstall, Start on boot=y, Scan on boot=y
• My first attempt at the following step failed with an error "Instantiating disk: failed". I found through a quick Google search that ASM was not initialized, so I started ASM by issuing oracleasm init. After that the following createdisk commands worked as expected.
  
• Next I set my empty partitions as candidate groups for ASM.

oracleasm createdisk data1 /dev/hda6 oracleasm createdisk data2 /dev/hda7
oracleasm createdisk data3 /dev/hda8
oracleasm createdisk data4 /dev/hda9 oracleasm createdisk data5 /dev/hda10 oracleasm createdisk data6 /dev/hda11

• I only created 6 at first, so I can play with adding more later. Verify with oracleasm listdisks. 6 disks are displayed DISK1-DISK6. Great.

INFRASTRUCTURE INSTALL: INSTALL THE INFRASTRUCTURE

At this point I unzipped my install media, and ran the Grid Infrastructure installer. Note: The documentation does not say switch to the 'oracle' user here, but runInstaller will not run as root, so I switched to the new oragrid user created earlier.

• This is where I hit my first permissions hiccup of having separate IDs for Infrastructure and Database. I happened to have the media files under /home/oracle11r2 not under /oragrid. Once I changed the group on /home/oracle11r2 to oinstall and granted group read/execute on it, oragrid could run the installer.
• Once OUI started, I selected "Install and Configure Grid Infrastructure for a Standalone Server"
• I picked English as my language.
• Next I was prompted to set up DISK GROUPS. Let's review..

ASM Disk Groups are the logical grouping of physical disks, representing the basic unit of storage that ASM presents either to the database for use, or to the operating system, via ACFS. Each Disk Group has a redundancy level, which sets the level of mirroring that ASM manages for you. High redundancy keeps 3 or more copies of the data within the disk group. Normal redundancy keeps 2 copies of data within the disk group (basic mirroring).

• First, I named my disk group ASMDATA, selected Normal redundancy, and selected all 6 devices as Candidate Disks. The failure groups for redundancy may be defined later? We'll find out.
• I set passwords for the SYS and ASMSNP accounts. Let's review again...

ASM uses Oracle Database technology to keep track of the storage it manages. ASM is essentially an instance of the Oracle Database, specially tailored for managing the data. It is relatively small overhead on the system as compared to an Oracle Database for an application. Many of the concepts of maintaining an Oracle database instance carry over to managing ASM, such as the SYS password, in this step. Treat ASM SYS and other passwords as securely as you do SYS for your Oracle Database.

• I assigned all the authentication groups to "oinstall" (default).
• Oracle Base = /u01/app/oragrid (default)
  
• Software Location = /u01/app/oragrid/product/11.2.0/grid (default, Very OFA-ish, no?)
• Inventory Directory = /u01/app/oraInventory (default)

• OUI checked for installation requirements, and here is where my home machine starts to fall short. The Physical Memory check failed... 1.5GB was required, and my system reports 1.48GB. It also did not recognize my swap space.
• There was a package ASM expected (pdksh-5.2.14) which I found, downloaded, and tried to install. I found it conflicted with ksh and bash already installed, so I left things as-is.
  
• The max file descriptor limit was set too low. OUI was able to generate a fixit script to take care of this one.
• I told OUI to ignore the remaining prerequisite checks and continue anyway... The goal is to learn so if this screws something up I will learn even more because of it.
• I elected to save a repsonse file. I'm not setting up a cluster, but this will be helpful to study, even on this standalone install.
• Installation continued without incident, and I ran the 2 scripts as root when prompted.
• ps -fu oragrid shows all the processes I would expect to see from an Oracle database instance
• Pulling up the System Monitor, I see a little bit of load and memory usage, but nothing that concerns me.
• /etc/mtab now contains a mount point for oracleasmfs
• I modified /etc/oratab to automatically start the instance "+ASM" on startup.
  

INFRASTRUCTURE INSTALL: POST-INSTALL REVIEW

There are several interesting things in the post-install steps.


Of particular interest:

• In a real system, patching is important. THe first post-install instruction is to apply patches. Do so. I'm not here, as it is out of scope for this exercise. Patching will be tried later.
• The 11gR2 Grid Infrastructure includes the listener. When managing the listener the ORACLE_HOME for the ASM/Grid Infrastructure installation must be used. I have to say I like this. I was never a fan of multiple listeners on a single node. I understood the reasoning of the DBAs who chose to run that way, but disagreed on the need.
• The 11gR2 Grid Infrastructure will support databases as old as 9.2.
  
• Backup the orainstRoot.sh script in /u01/app/oraInventory for future reference and troubleshooting. OK, done.
  
• We set up a single disk group during the installation. For installing 11gR2 we will want another disk group for the Flash Recovery Area. I'm already planning to pare down the 6 disks to maybe 4. We still have 4 partitions which we can use for an ACFS playground.
• The ASM utility binaries do not seem to be in the location expected in the postinstallation steps. This symbolic link is a helpful shortcut: ln -s /u01/app/oragrid/product/11.2.0/grid/bin /u01/app/11.2.0/grid/bin

USING ASM: CREATE ADDITIONAL DISK GROUPS

• Before adding new disk grounds, I need to enable to other partitions for ASM, with oracleasm (as root). Done. data7-data10 now exist.
• Logged in as oragrid, I go to /u01/app/11.2.0/grid/bin and run ./asmca to manage disk groups.
• I go to create new group. The HEADER STATUS column shows the state of all the devices available. I see my 4 new partitions PROVISIONED, and if I click "Show All" Member Disks, I see my other 6 have a status of MEMBER
• I created a disk group FRA from DISK7 and DISK8, with normal redundancy.
• I created a disk group FS from DISK9 and DISK10, with normal redundancy.
• We notice on each of these the Usable capacity is half the Size. normal redundancy is mirroring the data.
  

WRAP-UP: ASM IS INSTALLED

At this point, ASM has been successfully installed, and we can add and remove disks from disk groups at will. In the next installments we are ready to add a Database to the mix, try out the new-fangled File System, and (oh yeah, shut down and start everything up cleanly). I have 8 or 9 hours invested to this point, and that includes installing the operating system and writing this blog along the way.