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According to this article, ZFS is sub-optimal for databases due to fragmentation of the db files. Could you please comment? Thx. http://bartsjerps.wordpress.com

• nabla9 12y ago
  Oracle advice on how to configure ZFS and Oracle Database http://www.oracle.com/technetwork/server-storage/solaris/config-solaris-zfs-wp-167894.pdf http://www.oracle.com/technetwork/server-storage/solaris/con... Some picks: Free space is important 10-20%. >In an environment with a high rate of data update (or churn), it is advisable to maintain a certain amount of free space. ZFS is a copy-on-write file system and relocates all writes to free disk space. Keeping a certain amount of free blocks allows ZFS to easily find space in big chunks, allows ZFS to aggregate writes and reduce the write IOPS demand on hard disks. Streaming aggregated writes can be 50-100 times less demanding on hard drives than doing small random writes. Therefore, the incentive for keeping free space is high, especially in a high churn environment, such as an active OLTP database. >The number one rule for setting up an Oracle database on ZFS is to set ZFS recordsize equal to the database block size for the file systems that contain the Oracle data files. recordsize = db_block_size