Redirecting Bad Blocks - Novell NETWARE 6-DOCUMENTATION Manual

Redirecting Bad Blocks

18
NetWare Server Disks and Storage Devices Administration Guide
ranges in order to make the data area identical to the other partitions in the
group.)
Mirrored partitions must have the same sharable status.
Partitions you add to a mirror group cannot be part of any other mirror
group. They must be standalone Mirror objects.
The partitions you add must include the Mirror and Hot Fix options. You
select these options when you create the partition; you cannot add the
options later.
When you select Hot Fix, mirroring is automatically selected. You cannot
mirror partitions that do not have a Hot Fix Redirection Area.
Although you can mirror one partition to as many as eight other partitions,
mirroring two partitions is usually sufficient fault tolerance for most
systems.
If a mirrored disk fails and cannot be accessed by the server, you can
unmirror the hard disks and salvage the volume from the functional disk.
See "Recovering Data from an Out of Sync Disk" on page
If you want to remove a hot-plug mirrored disk without bringing down the
server, you must unmirror the disk first. See
page 37.
For information about how to set up mirroring and duplexing, see
and Duplexing Partitions" on page
Due to the constant reading and writing of data to disk, some disk storage
blocks lose their capacity to store data. NetWare uses Hot Fix to prevent data
being written to unreliable blocks.
The Hot Fix feature redirects the original block of data (still in memory) to the
Hot Fix Redirection Area of the NetWare partition. Once the operating system
records the address of the defective block in a section of the partition area, the
server will not attempt to store data in the defective block.
Hot Fix redirection can occur during a write request, a read request, or a read-
after-write verification.
Write redirection occurs when the disk reports an error during a write
request. The system marks the block as bad and redirects the data to a
different block.
"Unmirroring Partitions" on
37.
37.
"Mirroring