Acer Altos EasyStore - Adding Hard Disks

Altos eas
y
Store Manua
l
Appendix
B Disk Configurations
147
Adding hard disks
The effect of adding hard disks to your storage system varies, depending on the
disk con f iguration you chose when you configured the system and the curren t state
of the existing disks.
For example, in a linear configuration, you can add a new disk at any time, and da t a
can
be written to that disk as soon as it is added. (Access t o the disks is t emporarily
interrupted
while the disk is being added.) Whether you previously removed a disk
or one of t he other disks failed makes no dif f erence.
In a RAID configuration, the ef f ect o f adding a disk varies, depending on whether the
RAID is in a normal or degraded state (as indicated on the Disks page). A normal
state indicates that the RAID is functioning properly . A degraded state indicates that
one or more disks have been removed or failed , but because o f the da t a protection
offered by the RAID, you can con t inue to access all the data.
In a normal sta t e, you cannot add a disk to a RAID 0 or RAID 1 configura t ion. Any
disk
that you install will not be used unless you subsequently reconfigure the
storage system (as described in “Reconfiguring your storage system disks”).
Caution: Recon f iguring your storage system disks dele t es all t he data on your
storage
system.
However , if you currently have three disks and a RAID 5 configuration, you can add
a f ourth disk as a spare (essentially changing from RAID 5 to RAID 5 + spare while
retaining
all your existing data).
In a degraded state, you can add a disk to a RAID at any time, and the new disk will be
rebuilt to replace the disk that was removed or failed.
Caution: If the RAID has failed—that is, if so many disks have failed or been
removed
that the RAID can no longer f unction—you must either re-install the
disks or reconfigure the entire storage system, deleting all the da t a on your
system.
Although you can add a disk of any size to a linear configura t ion, any new disk that
you add to a RAID configuration must be the same size as or larger than the
smallest
existing disk in the RAID .