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Managing ZFS File Systems in Oracle® Solaris 11.3

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Updated: May 2019
 
 

Recommended File System Practices

The following sections describe recommended file system practices.

Root File System Practices

  • Consider keeping the root file system small and isolated from other non-root related data so that root pool recovery is faster.

  • Do not include file systems in rpool/ROOT, which is a special container that requires no administration and should not contain any additional components.

File System Creation Practices

The following sections describe ZFS file system creation practices.

  • Create one file system per user for home directories

  • Consider using file system quotas and reservations to manage and reserve disk space for important file systems

  • Consider using user and group quotas to manage disk space in an environment with many users

  • Use ZFS property inheritance to apply properties to many descendant file systems

When creating an Oracle database, consider the following file system practices:

  • Match the ZFS recordsize property to the Oracle db_block_size.

  • Create database table and index file systems in main database pool, using an 8 KB recordsize and the default primarycache value.

  • Create temp data and undo table space file systems in the main database pool, using default recordsize and primarycache values.

  • Create archive log file system in the archive pool, enabling compression and default recordsize value and primarycache set to metadata.

Monitoring ZFS File System Practices

You should monitor your ZFS file systems to ensure they are available and to identify space consumption issues.

  • Weekly, monitor file system space availability with the zpool list and zfs list commands rather than the du and df commands because legacy commands do not account for space that is consumed by descendant file systems or snapshots.

    For more information, see Resolving ZFS Space Issues.

  • Display file system space consumption by using the zfs list –o space command.

  • File system space can be unknowingly consumed by snapshots. You can display all dataset information by using the following syntax:

    # zfs list -t all
  • A separate /var file system is created automatically when a system is installed, but you should set a quota and reservation on this file system to ensure that it does not unknowingly consume root pool space.

  • In addition, you can use the fsstat command to display file operation activity of ZFS file systems. Activity can be reported by mount point or by file system type. The following example shows general ZFS file system activity:

    # fsstat /
    new  name   name  attr  attr lookup rddir  read read  write write
    file remov  chng   get   set    ops   ops   ops bytes   ops bytes
    832   589   286  837K 3.23K  2.62M 20.8K 1.15M 1.75G 62.5K  348M /
  • Backups

    • Keep file system snapshots

    • Consider enterprise-level software for weekly and monthly backups

    • Store root pool snapshots on a remote system for bare metal recovery