Replacing All Drives At The Same Time - IBM TotalStorage DS4300 Installation, User's, And Maintenance Manual

v Replacing the drives one at a time
The method you use depends on the following considerations:
v Which method most closely matches the recommended drive upgrade procedure
v Which RAID level is used on the affected drives. (RAID 0 requires you to replace
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

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 containing RAID 0 logical drives. All the data 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 subsystem, which makes the storage subsystem (and any attached storage
expansion enclosures) inaccessible to other users.
To replace all the drives at the same time, perform the following steps:
This method requires that you back up the data on the affected drives and then
turn off the storage subsystem. After replacing all the drives, you must
reconfigure the new drives and restore data from backup. See the procedure in
"Replacing all drives at the same time."
This is the safest way to exchange drives without losing data. However, this
method might take a long time to complete because of the backup,
reconfiguration, and restoration processes. In addition, other users are not able
to use the storage subsystem (or any storage expansion enclosures attached to
the storage subsystem) until you finish the procedure. You must use this method
on RAID 0 logical drives.
In this method, you manually fail each drive, replace it, and wait for the system to
restore data to the new drive before installing the next drive. After you install the
new drives, you can configure them to make the additional drive space available.
See the procedure in "Replacing the drives one at a time" on page 127.
Using this method, you can replace the drives while the storage subsystem is
running, eliminating the down time that is required if you replace all the drives at
once. However, this method is more risky because you can lose data if the drive
restoration or storage subsystem reconfiguration process fails. In addition, the
reconstruction process might take a long time. This method works only on
redundant logical drives (RAID 1, 3, or 5). You cannot use this method with any
drives containing RAID 0 logical drives.
Consider backing up your data if you use this method. This safeguards your data
if the restoration and reconfiguration process fails or the new drive malfunctions.
that is provided in the operating system or the storage-management software
documentation.
all the drives at the same time.)
for arrays consisting of 3 to 5 fibre channel drives. If you have more than 10
drives or SATA drives with a large capacity of 400G or 500G, consider replacing
all drives at the same time, as described in the next section.
1. Read the following information:
v The information in "Adding larger-capacity drives" on page 124, particularly
the paragraphs that discuss the differences between the two possible
upgrade procedures
v The information in your software documentation regarding drive upgrades
and installation
Chapter 5. Installing and replacing components
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