ICP GRD RD Series, Руководство пользователя

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(4) States of a RAIDYNE Array Drive
An Array Drive under the RAIDYNE operation system can assume seven different operatio-
nal modes. An Array Drive is fully operational when in the
ready state. All redundant infor-
mation is present, that is, a hard disk can fail without impairing the functionality of the
Array Drive. This is the normal state of an Array Drive.
idle ready fail build rebuild expand error
Idle state. This mode is characterized by the fact that the redundancy information of the
Array Drive has never been entirely created. An Array Drive assumes this state after its first
configuration and you exit GDTSETUP. If an error should occur while the array is in the
build
state, the array returns to the idle state (exception: if during the build state the dedicated
drive of RAID 4 fails, the state changes to fail ).
Build state. After the Array Drive has been configured for the first time, it changes from the
idle to the build state as soon as you quit GDTSETUP. While the array is in the build state,
redundancy information is calculated and stored to the hard disks of the array.
Ready state. The disk array is fully operational when in the ready state. All redundant infor-
mation is present, that is, a hard disk can fail without impairing the functionality of the disk
array. This is the normal state of a disk array. The state
ready/expand indicates that the RAID
level and/or capacity are currently migrated/expanded.
Fail state.
The Array Drive changes to the fail state whenever a Logical Drive fails. Redun-
dancy information is still present, thus allowing the remaining hard disks to continue to
work. This state should be eliminated as soon as possible by replacing the defective hard
disk. If a so-called Hot Fix drive has previously been assigned to an Array Drive with
GDTSETUP, the controller will automatically replace the defective drive and start the recon-
struction of the data and the redundancy information. Under these circumstances the
fail
state is only temporary and will be eliminated by the controller itself.
Rebuild state. The Array Drive will assume this state after the automatic activation of a Hot
Fix drive or after a manual replacement carried out with GDTSETUP. The data and the red-
undant information are reconstructed and stored to the new drive.
Expand state. If the capacity or RAID level of an existing Array Drive is changed, the Array
Drive changes its state into expand . As soon as the expansion or migration is completed, the
state changes back to ready.
Error state. If a second hard disk should fail while the Array Drive is in the fail or rebuild sta-
te, it is not possible to continue the working session without restrictions. The Array Drive is
still available for I/Os, but data loss and error messages on the host level are possible.
Some of these sates may become the addendum
patch
(e.g. build/patch , ready/patch ).
This word indicates that the original Array Drive went through a significant procedure. I.e.,
the parity information was recalculated anew.
Or, the Array Drive has been patched from the error state into the fail state. This may be-
come extremely helpful in a situation where two Logical Drives of an Array Drive fail at the
same time, but only one of the two Logical Drives is really defective and the other was
blocked out, since it was connected with the same I/O channel as the defective one. The
Array Drive's state is error and normally all data would be lost. RAIDYNE and GDTSETUP
include some functions, which allow the patch of this Array Drive from the error state into
the fail sate. Before the actual patch, the defective drive has to be physically removed from
the Array Drive. Such a patch-procedure is a real sheet-anchor and should only be used af-
ter a detailed consultation with a trained support person (a printout of the
Save Information
file is extremely helpful).