V
Variable prefetch
A cache prefetch strategy. The size of the data to be prefetched is the
multiple for prefetching multiplied by the length of a read command.
This strategy applies to the applications that require reading data of
variable size in a certain order, or to the situations where multiple
subscribers read data concurrently but no fixed prefetch size can be set,
because the amount of pre-read data cannot be judged. An example is
the streaming media demanded by multiple subscribers who use
different bit rates.
Virtual IP
addresses
The IP address is binded with specific NIC port of N8000 clustered NAS
engine. and this IP can't float between engines and usually is used to
services IP.
W
Waiting
The status of a LUN copy. Because the number of LUN copies that is
processed simultaneously reaches the maximum that the system
supports, the current LUN copy must wait in line.
Working
controller
The controller used by the array LUN to read and write a disk.
Write-back cache
A cache technology. When the write operation is completed, the data
continues to be stored in the cache and therefore, the operation of writing
the data to disks is delayed. There is no need to access disks during each
write operation.
Write-back cache
mirroring
A cache technology. Data is written to the local cache and at the same
time written to the opposite cache.
Write-through
cache
A cache technology. Data is written to disks. And only when the data
is safely written to disks, the procedure of write requests can be ended.
Disks need to be accessed during each write operation.
Z
Zone
In the fibre channel, a collection of the N_Port or the NL_Port that can
communicate with each other in the optical network. Only the N_Port
or the NL_Port in the same partition can communicate with each other
through the optical network.
OceanStor N8500 Clustered NAS Storage System
Installation Guide (for T Series V100R005)
C Glossary
Issue 02 (2015-09-22)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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