4.3 Planning for Your Storage Needs

Before you begin to subdivide, or carve, your physical disks, you should consider what your storage needs are and how you can effectively manage and divide your storage space to best meet your needs. Use the following guidelines when planning how to implement your storage solution:

4.3.1 Devices

NSS recognizes devices up to 2 TB in size. If you have physical or logical devices larger than 2 TB in size, you must carve them into logical devices of less than 2 TB each, using the vendor-provided or other third-party disk-carving software.

Storage devices can be local to the server, such as a system hard drive, or external to the server, such as with direct-attached storage or in a Fibre Channel or iSCSI storage area network (SAN).

A local hard drive typically hosts the system software and can optionally host applications and user data.

Linux

The operating system is stored on the system hard drive in a Linux traditional file system (such as ReiserFS or EXT3). The device is typically managed by LVM, but you can configure it to be managed by EVMS. For information, see Installing Linux with EVMS as the Volume Manager of the System Device in the OES Linux Installation Guide.

Use NSS data pools and volumes only on devices managed by EVMS.

NetWare

The operating system is stored on the system hard drive in the NSS sys pool and sys: volume.

NSS supports server clusters built with Novell Cluster Services™. Both local and SAN storage devices can be shared between the servers, depending on network connections. However, you cannot SAN boot cross-platform. For information, see the following:

For information about using NSS pools and volumes cross-platform, see Section 6.5, Compatibility Issues for Using NSS Cross-Platform.

4.3.2 Software RAID Devices

NSS supports software RAIDs 0, 1, 5, 10, and 15

If you use hardware RAID devices, software RAID devices are unnecessary. You can use both hardware and software RAID devices on the same server.

For more information, see Section 9.0, Managing Software RAID Devices.

4.3.3 Multiple I/O Paths (NetWare)

For NetWare, NSS provides multiple I/O paths for fault-tolerant connections between the server and its storage devices. For information, see Section 10.0, Managing Multiple Connection Paths to Devices (NetWare).

4.3.4 Free Space

Understanding how much free space you will need from each device helps you during the disk carving phase of the NSS configuration.

To maximize the performance benefits of software RAID devices, partitions used for the RAID should come from different physical devices. For software RAID 1 devices, the mirrored partitions cannot share any disks in common.

For information about space availability, see Section 7.3, Viewing Devices on a Server.

For Linux, only EVMS-managed devices show up in the NSSMU and the Storage plug-in to iManager. For information, see Section C.2, Viewing Free Space Available to EVMS-Managed Devices.

4.3.5 NSS Pools and Volumes

NSS is the primary storage file system on NetWare. NSS is a data storage file system on Linux.

Linux

Linux requires a Native Linux volume, such as Reiser or EXT2, for the operating system. Use NSS pools and volumes as data volumes only on devices managed by EVMS.

NetWare

The sys pool and sys: volume should be reserved for your system software. Create separate pools for applications and user data.

When creating a pool, assign up to 2 TB from free space for each partition. Use at least 4 partitions of up to 2 TB each to create the maximum-sized pool of 8 TB. To grow a pool, add more partitions of space, up to the limits.

Pools can contain space from multiple devices, using various amounts of free space from each. Pools can use multiple partitions from the same device.

To mirror pools, each pool must use partitions from different devices; mirrored pools can have no devices in common.

Pools can contain multiple volumes, but a volume belongs to only one pool.

When creating a volume, assign it a fixed administrative quota or allow the volume to grow dynamically to the size of the pool. Any given volume’s quota cannot exceed the size of the pool.

Pools can be overbooked. If a pool contains multiple volumes, the cumulative administrative maximum sizes of all volumes can exceed the pool size, using the overbooking feature, although real total size is bound by physical limitations. Because space is allocated to volumes as needed, a volume might not reach its quota.

You can create an NSS data volume on an OES Linux server or an OES NetWare server and then move the volume cross-platform. For information, see Section 6.5, Compatibility Issues for Using NSS Cross-Platform.

4.3.6 NSS Encrypted Volumes

Encrypted Volume Support is available only in NetWare 6.5 Support Pack 2 or later, OES NetWare and later, and OES SP1 Linux and later. Create encrypted volumes only after you verify a successful system install or upgrade. For information, see Managing Encrypted NSS Volumes.