DVS ProntoXway, Hardware Manual

Page: 45 / 78

5-3
2
1
3
5
4
Maintenance
I
A
Figure 5-1: Disk sets in the DVS system
If one hard disk within a disk set fails, the missing data can be recalcu-
lated due to the parity information stored on the other disks of the set.
Thus, a DVS system equipped with RAID 5 can withstand disk failures
without losing data or access to data.
5.1.2 Replacing a Hard Disk
In case of a hard disk failure an alarm will be sounded. Then during con-
tinuous accesses to the hard disk array you can identify the broken disk
easily: It will be the one no longer blinking (either continuously on or
off). With this you have the possibility at hand to replace the broken
disk.
If a second disk within the same disk set fails, your data will
be unrecoverable.
An alarm can be caused by a number of reasons. Please refer
to section “Troubleshooting” on page A-2 first for further de-
tails about what to do in case of an alarm.
If a hard disk of the hard disk array fails, the alarm will be
sounded by a RAID controller. It cannot be switched mute with
the mute button of the operation items. It can be turned off ei-
ther with the RAID software manager or by replacing the bro-
ken hard disk.
RAID 5 systems: Data accesses to the hard disk array are still
possible because any missing data will be recalculated from the
parity information distributed among the other hard disks of
the disk set. Normally this will limit the overall performance and
real-time operations may no longer be possible.
disk set 1
disk
se
t 2