HP Store Once 2700, 4500 and 4700 Maintenance and Service Guide

8 Disk replacement
This chapter describes:
• The storage RAID configuration
• How to identify a failed disk
• How to replace a disk
• How to rebuild the RAID if several disks fail
NOTE: For instructions on how to connect additional storage by adding a new capacity upgrade
enclosure (not available with the StoreOnce 2700 Backup system), please see the printed
documentation supplied with the additional storage.
RAID configuration
All HP StoreOnce Backup systems are supplied with their base storage already configured for use.
This storage comprises the disks in the storage system itself. On some models there are dedicated
disks for the operating system; on others the operating system and backup data storage are all on
the same disks.
Table 9 RAID configuration
Notes
Number of disks (and
location)HP StoreOnce model
This is a RAID 5 system; operating system and backup data are stored
on the same RAID Set.
4 x 2 TBHP StoreOnce 2700
This allows for a single drive failure without loss of either the backup
data or OS partitions.
Two disks (disk 1 and 2) are dedicated for use by the operating system
and are in a mirrored configuration, such that one disk can be lost
without the system failing.
12 x 2 TBHP StoreOnce 4500
The remaining 10 disks in the system are in a RAID 6 set which contains
the backup data, two disks can be lost in this system without loss of
the backup data.
Up to three 12–disk additional enclosures may be added to increase
the backup data capacity, also RAID 6.
The two disks in the head server unit are dedicated for use by the
operating system and are in a mirrored configuration, such that one
disk can be lost without the system failing.
2 x 1 TB in the head
server unit
Plus 12 x 2 TB in
storage enclosure(s)
HP StoreOnce 4700
One pre-configured enclosure of 12 disks is supplied with the head
server unit for user data; these disks are in a RAID 6 set, such that two
disks per enclosure can be lost without loss of backup data.
Up to seven additional enclosures may be added to increase the backup
data capacity, also RAID 6. The HP StoreOnce 4700 supports daisy
chaining.
IMPORTANT: It is very important that failed disks are replaced promptly.
In order to ensure that you are alerted to disk failures ensure that either or both of SNMP traps
and email alerts are configured so that in the event of a disk failure you are notified immediately
and can take action to replace the disks.
Note that ALL enclosures of storage must be working for the system to operate; if the RAID fails on
any one enclosure due to exceeding the maximum amount of failed disks then ALL data is lost. In
the case of the HP StoreOnce 2700 Backup system, if more than one disk fails then the data and
32 Disk replacement