ICP RS Series, User Manual, Page: 70 / 193

70
C.8 Methods for the Replacement of a Disk Drive
The ICP Controller and the ICP Firmware offer a variety of possibilities to replace a defective
disk drive. If and when to use them depends on the physical environment of your server.
With some servers the disk drives are just mounted into the server enclosure, they are not
removable. With other servers there is a backplane which is intelligent (e.g., with SAF-TE)
and which hosts a number of disk drives with the SCA connector (Single Connector At-
tachment). Another type of server has the disk drive in hot pluggable disk carriers which
have become pretty popular during the last 2 years. These carriers are often "stupid" and do
not communicate with the ICP Controller or server. Though, they can display the disk
drive`s temperature or the status of their build in fan.
Manual Hot Plug Manual Hot Plug Manual Hot Plug Manual Hot Plug Auto Hot Plug Auto Hot Plug Auto Hot Plug Auto Hot Plug Automatic Replacement Automatic Replacement Automatic Replacement Automatic Replacement
with Hot Fix Drive
with Hot Fix Drive with Hot Fix Drive with Hot Fix Drive
Typical Server Typical Server Typical Server Typical Server
Env
Env Env Enviiiironment ronment ronment ronment
Low Cost.
Disk Drives are physically
mounted in the server enclo-
sure and are not removable.
Additional cost for external
enclosure, cables, backplanes,
etc..
Disk Drives are installed re-
movable in an intelligent or
non-intelligent subsystem. The
subsystem complies with one
of the following enclosure
standards:
ƒ
"SAF-TE" (SCSI Accessed
Fault Tolerant Enclosures)
ƒ
"SES" (SCSI Enclosure
Services)
ƒ
"Intelligent Fault Bus"
(former DEC™ fault bus)
ƒ
Non-Intelligent Subsys-
tems using hot pluggable
disk carriers
High availability.
Right from the begin-
ning, the ICP Controller
has a spare drive. In the
case that one drive of
an Array Drive has
failed, the spare drive
(we at ICP call it Hot Fix
Drive), is automatically
build into the Array
Drive. Without any user
interaction the Array
Drive is becoming, re-
dundant, again.
Description Description Description Description
ICP RAID Console or ICP RAID
Navigator guides the user to
the point where the new disk
drives can be build into the
Array Drive. The subsystem has to be con-
figured with ICP RAID Console
or ICP RAID Navigator, before
the Auto Hot Plug can work.
Thereafter a disk drive can just
be pulled out and plugged in
again, and the ICP Controller
"knows" what to do. In addi-
tion, SAF-TE and SES report
the enclosure status (power
supplies, fans, temperature
etc.) to the ICP Controller and
the ICP driver. The Hot Fixe Drive is
assigned to an Array
Drive. There are two
types of Hot Fix Drives:
ƒ
Private Hot Fix
Drive
(Available for one
Array Drive, only)
ƒ
Pool Hot Fix Drive
(Several Array
Drives share this
Hot Fix Drive)