DiskSuite and DiskSuite Tool Functionality

DiskSuite offers better performance, greater capacity, easier administration, and improved availability of disk storage on SPARC and x86 systems.

With DiskSuite, data availability and reliability are improved with up to three-way mirroring. You can mirror root (/), /usr, swap, or any file system. You can also mirror existing file systems and automatically replace failed components within a mirror using hot spare facilities. The mirrors feature includes optimized resyncing, which reduces the time required for synchronization.

The UNIX file system (UFS) logging facility provides faster local directory operations, speeds up reboots, and decreases synchronous disk writes by recording file system updates in a log before they are applied to the UNIX file system.

In addition, DiskSuite's disk striping can increase performance. Striping spreads data requests over multiple components. Concatenation and striping increase capacity by grouping several components into a single larger logical device.

The information about the configuration and state of all metadevices is preserved in a replicated state database. These databases are essential for the operation of DiskSuite.

Administration is simplified by the hot spare facility and the dynamic growth of metadevices and file systems.

Solstice DiskSuite 4.0 also features the creation of RAID (level 5) configurations and administration of metadevices within disksets. RAID provides recovery from disk failure in a more cost effective way than disk mirroring. A diskset is a grouping of two hosts and disk drives in which all the drives are accessible by both hosts.

Getting Help

If you have problems installing or using DiskSuite Tool, call the distributor from which you purchased the software and provide the following information:

• Your name and electronic mail address (if available)
• Your company name, address, and phone number
• The model and serial number of your system
• The release number of the operating system (for example, Solaris 2.4)
• Any additional information that will help diagnose the problem

Supported Software and Hardware

DiskSuite Tool may only be used on systems that are running Solaris 2.4 or a later version of the Solaris operating system. The system must have DiskSuite 4.0 or a later version installed. The Motif^(TM) runtime package (SUNWmfrun) must be installed.

DiskSuite 4.0 runs on all SPARC and x86 systems that are running Solaris 2.4 or a later Solaris 2.x release.

The peripherals supported by DiskSuite and DiskSuite Tool include:

• IPI disk drives
• SCSI disk drives
• IDE disk drives (x86 only)

---

Note - The root file system cannot be mirrored on an IDE drive.

---

Disk Naming

DiskSuite Tool uses the normal disk naming convention for all drives. This naming is, cntndnsn, where cn is the controller number, tn is the target, dn is the disk, and sn is the slice.

---

Note - However, be aware that on x86 systems, IDE drives do not have a target number. All the examples and instructions in this manual are from a SPARC system and show the target number.

---

Definition of Terms

The following are general definitions for DiskSuite and DiskSuite Tool:

Attach submirror - to add a submirror to an existing mirror. DiskSuite automatically resyncs the submirror with other submirrors.

Attach logging device - to add a logging device to an existing trans device.

Button - a graphical component on a window frame or in a dialog box that works by pressing it using the mouse.

Cascading menu - a submenu that provides selections that extend the parent selection on a pull-down or pop-up menu.

Component - the physical slice (partition) that is part of a metadevice.

Concatenated Stripe - a metadevice that is made up of both concatenated and striped components.

Concatenation - a metadevice created by sequentially mapping blocks on physical slices (partitions) to a logical device. Two or more physical components can be concatenated. The slices are accessed sequentially rather than interlaced (as with stripes).

Detach logging device - to remove a logging device from a trans device.

Detach submirror - to remove a submirror from a mirror.

Dialog box - a secondary window that conveys to or requests information from the user. Dialog boxes block the application until they are dismissed.

Diskset - an association of two hosts and group of disk drives in which all the drives are accessible by each host.

Drag and drop - using the mouse to select and move objects in a window or between windows. To drag and drop, press the middle mouse button, move the object to the desired location, and release the button.

Highlight - a visual cue signaling the current selection or current location of a selected object.

Hot spare - a component set up to automatically take over for a failed component of a mirrored or RAID metadevice.

Hot spare pool - a group of spare components that automatically replace failed components.

Icon - a small graphical image used to represent a window. Windows can be turned into icons or minimized to save room or clean up the workspace.

Interlace - the number of blocks on a component of a striped or RAID metadevice that can be accessed simultaneously with the same number of blocks from other components. The interlace value tells DiskSuite how much data to place on a component of a striped or RAID metadevice before moving on to the next component.

Logging - recording UNIX file system (UFS) updates in a log (the logging device) before the updates are applied to the UNIX file system (the master device).

Logging device - the component that contains the log for a trans device.

Master device - the component that contains the file system for a trans device.

Menu bar - a rectangular area at the top of the window, containing the titles of the pull-down menus.

Metadevice - a group of components accessed as a single logical device by concatenating, striping, mirroring, setting up RAID devices or logging the physical devices. Metadevices are sometimes called pseudo devices in UNIX domains.

Metadevice state database - information kept in nonvolatile storage (on disk) for preserving the state and configuration of metadevices.

Metadriver - a pseudo device driver that maps metadevice operations to operations on the metadevice components.

Mirror - a special type of metadevice made up of one or more other metadevices called submirrors. See also submirrors.

Mirroring - replicating all writes to a single logical device (the mirror) to multiple devices (the submirrors), while distributing read operations. This provides redundancy of data in the event of a failure.

Optimized resync - an update of only the submirror regions that are not in sync when the system reboots. The metadisk driver knows which regions of the submirrors are not identical (in sync) on all submirrors after a crash.

Partial resync - resyncing only a replaced component of a submirror or RAID device, rather than the entire submirror or RAID device.

Pop-up menu - a menu that provides no visual cue to its presence, but pops up when users perform a particular action. Pop-up menus are associated with a particular area of the workspace, such as the client area of an application.

Pull-down menu - a menu that is pulled down from a client application's menu bar.

RAID - an acronym for Redundant Arrays of Inexpensive Disks.

Replica - a copy of the state database. Keeping copies of the state database protects against the loss of state and configuration information. This information is critical to all metadevice operations.

Resync region - a division of a mirror that enables tracking changes by regions of the mirror, rather than over the entire mirror.

Resyncing - copying data from one submirror or RAID device to another after system crashes, submirror failures, or after a submirror is added. Resyncing ensures the data on all submirrors and on all RAID devices is identical.

Selection button - the mouse button used to make a selection.

State database - a dedicated portion of a disk reserved exclusively for the metadisk driver.

Stripe - similar to concatenation, except the addressing of the component blocks is interlaced on the slices (partitions), rather than sequentially. Striping is used to gain performance. By striping data across disks, multiple controllers can access data simultaneously.

Submirror - a metadevice that is part of a mirror. See also mirror.

Trans device - a special type of metadevice used for UFS logging. A trans device is composed of one or more other metadevices or components: a master device and optionally a logging device.

UFS - an acronym for the UNIX file system.

UFS logging - recording UNIX file system (UFS) updates to a log (the logging device) before the updates are applied to the UFS (the master device).