Restore an RMAN backup to a different host


Oracle RMAN is a powerful tool with many features for recovering datafiles, tablespaces or even single blocks, as well as cloning databases for non production uses.  However restoring a database to an entirely different server (or set of servers) it was backed up from is a somewhat cumbersome process.

In this post we will restore an RMAN backup to a new host, keeping the same database name and datafile names.

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RMAN Restore fails with “PSDRPC returns significant error 3113”

When using RMAN to restore a database to a new host, the recover database step fails with:

Crosschecked 43 objects
PSDRPC returns significant error 3113.
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 03/18/2017 19:31:23
ORA-03113: end-of-file on communication channel

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EMC Unity Storage Performance testing with Oracle ASM and SLOB

I’ve been testing the new EMC Unity 600F all-flash storage array with an Oracle database to determine the impact of storage compression on Oracle I/O performance.  To do this I have been using Kevin Closson’s SLOB tool.

SLOB is an excellent tool for testing I/O performance as seen by Oracle.  Unlike Swingbench which mimics a real application and therefore spends much of its execution cycle on the server CPU, SLOB concentrates exclusively on generating I/O from the Oracle stack.

Conversely, don’t expect SLOB to generate meaningful data to test ranking or sorting operations inside of Oracle.  SLOB generates entirely synthetic data that is meaningless from an application standpoint.

The following posts covers using SLOB to test I/O performance, and what was learned from the testing against the Unity 600F all-flash array.

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Experimenting with ASM Filter Drivers

Oracle is moving away from ASMlib, and introducing ASM Filter Drivers as a replacement.

ASM Filter Drivers will handle consistent device naming and permissions, as well as filter out illegal IO to ASM devices to protect against rogue dd commands corrupting ASM disks.

Future plans include support for TRIM commands to enable thinly provisioned disks to reclaim deleted blocks without having to resort to the massively dangerous ASRU tool.

ASM Filter Drivers were introduced with Oracle, but the implementation is currently one massive kludge.  By default on, OEL7 is not supported without a patch (patch 21053000).  OEL6 UEK is also not supported without a patch (patch 18321597).

Note that the patches require OPatch, but Oracle Grid Infrastructrue installs OPatch so you have to patch the patcher (patch 6880880), so you can patch the Oracle software, to make Oracle ASM Filter Drivers work with Oracle’s own operating system kernel.  Clear?  Good!

You cannot install Filter Drivers by default.  You have to migrate to them from UDEV or ASMlib.

Oracle 12.2 should hopefully fix this mess and make Filter Drivers actually usable, but in the meantime it might be fun to play with the new technology and see what it can do.

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ASM Filter Drivers – disks not filtering on reboot



You’ve enabled ASM Filter Drivers, migrated your existing disks, and then after you reboot you see this:

[oracle@oel6solo ~]$ asmcmd afd_lsdsk
Label Filtering Path

You check the ASM Filter Driver state and it says it is loaded and filtering:

[oracle@oel6solo ~]$ asmcmd afd_state
ASMCMD-9526: The AFD state is 'LOADED' and filtering is 'DEFAULT' on host ''

There is one more step that much of the documenation is missing:

[oracle@oel6solo ~]$ $ORACLE_HOME/bin/asmcmd afd_filter -e

Now the ASM FD filtering will survive a reboot:

[oracle@oel6solo ~]$ asmcmd afd_lsdsk
Label Filtering Path
DATA2 ENABLED /dev/sdc
DATA4 ENABLED /dev/sde
DATA3 ENABLED /dev/sdd
DATA1 ENABLED /dev/sdb