By uwes on Mar 29, 2012
Effective immediately a customer can now use ODA with
database files stored on an external NFS file server for both read
and write operations. This effectively eliminates ODA's 4TB
storage capacity limit, which has been a concern with some of
potential ODA customers.
Below is some additional information regarding the ODA external storage support
Q: What are we announcing?
A: Effective immediately, you can now use the Oracle Database Appliance with database files stored on a NFS-attached file server for both read and write operations.
Q: Does this differentiate the Oracle Database Appliance from an Oracle Database running on a 3rd-party server?
A: No, this feature is a generic feature of the Oracle Database. This puts Oracle Database Appliance on par with other Oracle Database server platforms.
Q: Is there an approved list of NFS servers I can use with the Oracle Database Appliance?
A: No, but we strongly recommend using a commercial file server such as an Oracle ZFS Storage Appliance, or a similar product from a major storage vendor (i.e., EMC, NetApp).
Q: Do I use ASM with the NFS-attached storage?
A: No. Simply mount the file system and store your files on it the same way you would store Oracle database files in any file system. Use of ASM for NFS-attached storage is not recommended.
Q: Can I have some of their database files on internal ODA storage, and some on NFS-attached storage?
A: Yes, you can have a mix of tablespaces—some on the local SAS storage internal to the ODA, and some on the NFS server.
Q: Can I create an ASM diskgroup that spans the local storage and the NFS storage?
A: No. ASM diskgroups should be constructed on disks internal to the ODA. ASM is not needed (nor recommended) for use on NFS-attached storage.
Q: If I don’t use ASM with my NFS Filer, how do I online add storage to my NFS-attached file system.
A: Most commercial NFS filers provide this functionality.
Q: Will I be required to patch their storage sub-system separately or will the ODA patching process take care of the NFS server?
A: The ODA patching process will only patch the local ODA server. If patches are required for an NFS filer, the customer is responsible for patching that themselves.
Q: If I put critical business data on an NFS filer and the server is down, what happens?
A: Your database is down. Make sure you use a highly available NFS filer.
Q: if I put non-critical archive data on an NFS filer, can I configure it so a failure to the filer won’t affect my database?
A: Yes, mark the archive data read-only, and set the init.ora parameter READ_ONLY_OPEN_DELAYED=TRUE
Q: What NIC in the ODA should I use to connect to NFS-attached storage?
A: The ODA has plenty of NICs. Use a bonded pair that is not in use.
Q: What mount options should I use?
Q: Where can I find more information?
Q: What is Direct NFS (dNFS)?
A: dNFS is a feature of the Oracle Database that allows an NFS client in the database kernel to directly connect to and access data on an NFS Filer.
Q: Should I used the native OS client or dNFS to connect to my NFS Filer?
A: You can use either, but Oracle recommends using dNFS.
Q: How do I configure and use dNFS?
A: Refer to MOS note 762374.1.
Q: How can I use Hybrid Columnar Compression (HCC) with ODA?
A: HCC is available for use with database files stored on and Oracle ZFS Storage Appliance. You can thus use HCC with ODA as long as the files are stored on and NFS-attached ZFS Storage Appliance. Your ODA must be running 18.104.22.168 database (releasing in April 2012) and you must connect via dNFS.
Q: How should I distribute my data between the local storage and the NFS filer?
A: Put hot data on the internal storage, as that will give the best performance. Put colder data on the NFS filer.
Q: I have tables containing both hot and cold data. How can I move just the cold data to the filer without affecting the application which expects everything in one table?
A: Use the database partitioning option to keep data in different partitions. Place the hot data in partitions on the internal storage, and cold data in partitions on the NFS Filer.
Q: Is there a limit to the amount of data I can store on the NFS Filer?
A: Yes, it is limited by the maximum database size supported by the Oracle Database. This is very big.
Q: Is there a white paper on this subject I can read?
A: An ODA specific white paper will be available shortly. In the mean time, a dNFS white paper is available describing the generic functionality. You can find it here: http://www.oracle.com/technetwork/articles/directnfsclient-11gr1-twp-129785.pdf