Protecting Against Data Loss After A Medium Power Loss - NEC Express5800/320Ma Software Installation And Configuration Manual

Protecting Against Data Loss after a Medium Power Loss

Protecting Against Data Loss after a Medium Power Loss
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If you push the power button when power is restored after a power loss, you may need
to reinstall the operating system if the boot disks are in internal . If the UPS has shut
down the system but the UPS has not removed power (because power was only briefly
lost), the UPS eventually attempts to restart the system by turning off power to the
system and then turning power on. If you have rebooted the system, the UPS interrupts
the boot process when it turns off power to the system. This power-on/power-off
sequence can corrupt the boot disk. When the UPS turns power back on, the system
attempts to boot from the partner boot disk, but because the partner boot disk has an
earlier time stamp than the boot disk used in the first attempt, the system fails the boot
attempt. The system then attempts to boot from the original boot disk, but this attempt
fails if the boot disk was corrupted by the earlier power-on/power-off sequence. If this
series of events occurs, you need to reinstall the operating system, or restart the
system from a backup system disk.
You may lose data if the boot disks are in external , and internal contains data disks
with mirrored volumes. If a power failure occurs, the volumes will not be synchronized.
If the system brings into operation the disks that contain stale data, the (stale) data on
the disks is restored and any data received after the loss of power is lost.
A-8 Express5800/320Ma: Software Installation and Configuration Guide
C A U T I O N
If the system is connected to a UPS, and the UPS briefly
loses power and shuts down the system, do not push the
power button on the Express5800/320Ma system to
restart it.
Allow the UPS to restart the system as configured. The
UPS automatically restarts the system when power is
restored after a power loss. Otherwise, the system may
fail to boot and, if it does fail, you will need to reinstall the
operating system or you may lose data.