RAID Utility User Guide Instructions for setting up RAID volumes on a computer with a Mac Pro RAID Card or Xserve RAID Card
Contents 3 3 4 4 6 7 8 9 10 10 11 11 11 12 15 16 17 18 2 RAID Utility User Guide The RAID Utility Window Running RAID Utility About Battery Status Setting Up RAID Volumes Migrating an Existing Volume to a RAID Volume Creating a RAID Set Creating a Volume Expanding a Volume Moving a Volume Setting Up a Spare Drive Reverting a Spare Drive Deleting a Volume or RAID Set Solving Problems Using the Command Line About RAID Levels Using Non-RAID JBOD Drives Setup Examples
RAID Utility User Guide This guide shows you how to set up RAID volumes using the RAID Utility application on a computer with a Mac Pro RAID Card or Xserve RAID Card. With a Mac Pro RAID Card or Xserve RAID Card installed in your computer, you can use RAID Utility to turn your computer’s internal disks into storage volumes based on RAID (redundant array of independent disks) schemes that improve performance and protect your data.
Running RAID Utility The RAID Utility application is in /Applications/Utilities/. You can open it from there anytime you want to reconfigure or check the status of the RAID components in your computer. You can also run RAID Utility from the Installer when you start up your computer using the Mac OS X or Mac OS X Server installation disc that comes with the computer. Choose Utilities > RAID Utility while you’re in the Installer.
Important: Don’t restart or shut down your computer during conditioning. Doing so interrupts the charging cycle and delays the use of the write caches. Repeated interruptions can prevent the battery from accepting or delivering a full charge.
Setting Up RAID Volumes There are two basic ways to set up RAID volumes: ÂÂ Migrate your existing startup volume ÂÂ Set up RAID sets and volumes manually For examples of some typical setups, see “Setup Examples” on page 18.
Migrating an Existing Volume to a RAID Volume When you purchase a computer with the RAID card installed but no solid-state drive, the startup disk is already configured as a single-drive Enhanced JBOD RAID set. You can convert this RAID set, along with one, two, or three other drives, to a RAID volume using the Migrate RAID Set command. All files on the original disk are retained in the new RAID volume. Any data on the additional drives is erased.
Under Options, choose whether you want to use space from the additional drives to expand the existing volume or leave the extra space free for creating other volumes later. Expand volume using added capacity: Expands the original startup volume to use all available space on the new RAID set. If you don’t select this option, RAID Utility retains the original startup volume on the new RAID set and leaves the remaining space on the RAID set free for you to create other volumes when you want.
To create a RAID set: 1 Open RAID Utility and click Create RAID Set. 2 In the dialog that appears, select the RAID level you want to use. The RAID levels you can select depend on the number of drives you select. If the RAID level you want to use isn’t enabled, try selecting a different number of drives. 3 Select the drives you want to include in the set. 4 Select the options that you want to apply to the set.
This is initially set to the size of the underlying RAID set, but you can enter a smaller size and save the remaining space to create other volumes. 5 Click Create Volume. You can start using the volume as soon as its icon appears in the Finder, but maximum read and write performance isn’t available until the volume is completely initialized. Until then, the volume status icon in RAID Utility is yellow. Initialization time depends on the RAID level of the underlying RAID set.
Setting Up a Spare Drive You can set aside an unassigned drive as a global spare. Then, if any drive in a RAID set fails, the spare is automatically integrated into the set to take the place of the failed drive. Only RAID 1, RAID 0+1, and RAID 5 sets can take advantage of spare drives. To set up a spare drive: 1 Open RAID Utility. 2 Select the drive you want to use as a spare in the left column. 3 Choose RAID > Make Spare.
Solving Problems The following paragraphs may help you identify or solve a problem you’re having with your RAID volumes. If the Battery Isn’t Fully Charged If you just installed the RAID card, the battery might not have finished conditioning. Conditioning can take up to 12 hours and starts when you first turn on the computer after installing the card. If you’ve been using the card for more than three months, the battery might be in a reconditioning cycle.
Checking the Status of RAID Components You can use RAID Utility to check the status of the RAID card, its battery, your RAID volumes, and the drives and RAID sets they’re built on. Overall status List of events To check the status of a component: 1 Open RAID Utility. 2 Click an item in the left column. You can also check RAID component status using System Profiler. Choose About This Mac from the Apple menu and click More Info. Then select Hardware RAID under Hardware in the Contents list.
Verifying a RAID Set You can use the Verify RAID Set command to confirm that data stored on a RAID 1, RAID 0+1, or RAID 5 volume is protected. The performance of the RAID set and any volume based on it is degraded during verification. To verify a RAID set: 1 Open RAID Utility. 2 Select the RAID set in the left column. 3 Click Verify RAID Set.
If a Drive Fails If a RAID set or volume becomes degraded because a drive has failed, you can use RAID Utility to identify the drive that needs to be replaced. Note: If your RAID setup includes a spare drive, it is automatically incorporated into the RAID set, and the set switches from degraded to good as soon as the recovery process finishes. If there is no spare, the set remains degraded until you replace the failed drive, and if a second drive fails before you replace the first, you could lose data.
About RAID Levels RAID Utility lets you set up RAID sets based on the following RAID levels: ÂÂ Enhanced JBOD ÂÂ RAID 0 (striping) ÂÂ RAID 1 (mirroring) ÂÂ RAID 0+1 (mirroring a striped pair) ÂÂ RAID 5 (striping with distributed parity) Enhanced JBOD Using Enhanced JBOD, you can create a RAID set using a single drive. The resulting RAID set doesn’t gain the performance or data protection of the other RAID levels, but it does benefit from the data caching and battery backup provided by the RAID card.
Using Non-RAID JBOD Drives Drives that aren’t part of the RAID environment are called JBOD disks (just a bunch of disks). If you install a new drive or a drive taken from a computer without a RAID card, it’s treated as a JBOD disk. If you install an unformatted drive, you see a dialog that asks you how you want to proceed. Open Disk Utility: Opens Disk Utility so you can erase or partition the drive and then use it in the Finder like any other disk.
Setup Examples The following examples show some common ways to set up RAID volumes. Migrating to a Single RAID Volume This is the easiest way to set up a RAID volume on a new computer. There’s no need to reinstall the operating system or restore existing files on the computer’s startup disk. However, the migration process does take some time and you can’t use the new volume until the process is finished. The example assumes that you’ve purchased a computer with a RAID card and four 500 GB disk drives.
Creating a Separate High Performance Data Volume As in the previous example, we’ll assume that you’ve purchased a computer with a RAID card and four 500 GB disk drives. In this example, you want to take advantage of RAID to create a fast data volume (for video editing, perhaps) and aren’t worried about data protection. You’ll leave the current startup disk as is, and use a RAID 0 scheme to create a separate volume on the remaining disks.
