Replacing All Drives At The Same Time - IBM DS3500 Installation, User's, And Maintenance Manual

v How much downtime is acceptable as you swap the drives.
v The number of drives in an array. Replacing drives one at a time is better suited to arrays that consist
of three to five drives. If you have more than 10 drives, consider replacing all drives at the same time.
v How much risk of losing data is acceptable. Because the array is in a degraded state during the RAID
array reconstruction and copyback process as result of replacing a drive in the array, any new drive
failure will cause the array to fail (causing a loss of data availability and even a loss of data). The
duration of the reconstruction and copyback process can be quite long, depending on the size of the
RAID array.
v How extensively the data will be changed while the array is in a degraded state during the RAID
array reconstruction and copyback process as a result of replacing a drive in the array. The more
extensive the data changes are, the more work that will have to be performed to restore the data in the
event that the array fails because an additional drive fails while the array is in a degraded state.

Replacing all drives at the same time

Use this procedure to replace all drives at the same time. You must use this method if you are upgrading
drives that contain RAID 0 logical drives. All the data that is currently on the drives is lost when you
replace the drives; therefore, you must back up all data that is currently on the drives. This procedure
also requires you to turn off the storage enclosures and the DS3500, which makes the storage subsystem
(and any attached storage enclosures) inaccessible to other users.
Attention: After you remove a drive, wait 70 seconds to allow the drive to spin down before you
replace or reseat the drive. Failure to do so might cause unpredictable results.
To replace all the drives at the same time, complete the following steps:
1. Read the following information:
v The information in "Replacing multiple drives" on page 5-17, particularly the paragraphs that
explain the differences between the two possible upgrade procedures
v The information in the software documentation about drive upgrades and installation
v The documentation that comes with the new drives
Read all precautionary notes, kit instructions, and other information. Kit instructions often contain
the most current information about the drives and their installation, plus upgrade or servicing
procedures. Compare the kit instructions with this procedure to determine whether you must
modify this procedure.
2. Use the Storage Manager software to check the status of the DS3500. Correct any problems that are
reported.
3. Perform a complete backup of the drives that you are replacing.
You need the backup to restore data on the drives later in this procedure.
Attention: When you handle static-sensitive devices, take precautions to avoid damage from static
electricity. For details about handling static-sensitive devices, see "Handling static-sensitive devices"
on page 2-3.
DANGER
Electrical voltage and current from power cables are hazardous. To avoid a shock hazard,
always place electrical equipment on dry, static-free level surfaces. Never turn on any electrical
equipment when there is evidence of fire, water, or structural damage.
4. Unpack the new drives. Set the drives on a dry, static-free level surface, away from magnetic fields.
Save the packing material and documentation in case you have to return the drives.
5. Complete the following steps:
a. Stop all I/O activity to the storage subsystem and attached storage enclosures.
b. Make sure that all of the green drive activity LEDs on the front of the storage subsystem (and on
all attached storage enclosures) are not flashing.
5-18
System Storage DS3500 and EXP3500: Installation, User's, and Maintenance Guide