HP Z1 Maintenance And Service Guide

Software RAID solution
This section provides a summary of software RAID considerations when running the Linux operating
system, as well as references to configuration procedures.
Software RAID considerations
The Linux kernel software RAID driver (called md, for multiple device) offers integrated software RAID
without the need for additional hardware disk controllers or kernel patches. All that is required are
multiple hard disks and a small amount of setup. Unlike most hardware RAID solutions, software RAID
can be used with all types of disk technologies, including SATA, SAS, SCSI, and solid-state drives.
Compared to hardware-based RAID, software RAID has disadvantages in managing the disks,
breaking up data as necessary, and managing parity data. The CPU must assume some extra loading:
disk-intensive workloads result in roughly double the CPU overhead (for example, from 15% to 30%).
For most applications, this overhead is easily handled by excess headroom in the processors. But for
some applications where disk and CPU performance are very well balanced and already near
bottleneck levels, this additional CPU overhead can become troublesome. Hardware RAID offers
advantages because of its large hardware cache and the capability for better scheduling of operations
in parallel. However, software RAID offers more flexibility for disk and disk controller setup.
Additionally, hardware RAID requires that a failed RAID controller must be replaced with an identical
model to avoid data loss, whereas software RAID imposes no such requirements.
Some software RAID schemes offer data protection through mirroring (copying the data to multiple disks
in case one fails) or parity data (checksums that allow error detection and limited rebuilding of data in
case of a failure). For all software RAID solutions on HP workstations, redundancy can be restored only
after the system is shut down so that the failed drive can be replaced. In software RAID, this
replacement requires only a minimum amount of work.
Performance considerations
Disk I/O bandwidth is typically limited by the system bus speeds, the disk controller, and the disks
themselves. The balance of these hardware limitations, as affected by the software configuration,
determines the location of the real bottleneck in the system.
Several RAID levels offer improved performance relative to a standalone disk. If the disk throughput is
lessened by a single disk controller, there is probably little you can do with RAID to improve the
performance without adding another controller. On the other hand, if the raw disk performance is the
bottleneck, a tuned software RAID solution can dramatically improve the throughput. The slower the
disk is relative to the rest of the system, the better RAID performance will scale, because the slowest
piece of the performance pipeline is being directly addressed by moving to RAID.
Software RAID solution
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HP Z1 Specifications

General

Tcase	72.6 °C
Bus type	DMI
Stepping	D2
FSB Parity	No
Processor cache	8 MB
Processor cores	4
Processor model	E3-1245
System bus rate	5 GT/s
Processor series	Intel Xeon E3-1200
Processor socket	LGA 1155 (Socket H2)
Processor threads	8
Processor codename	Sandy Bridge
Processor frequency	3.3 GHz
Processor cache type	Smart Cache
Processor lithography	32 nm
Processor manufacturer	Intel
Processor front side bus	- MHz
PCI Express slots version	2.0
Processor boost frequency	3.7 GHz
Processor operating modes	64-bit
ECC supported by processor	Yes
Thermal Design Power (TDP)	95 W
Number of processors installed	1
CPU multiplier (bus/core ratio)	33
Maximum number of PCI Express lanes	20
Memory types supported by processor	DDR3-SDRAM
Memory clock speeds supported by processor	1066, 1333 MHz
Memory bandwidth supported by processor (max)	21 GB/s
Maximum internal memory supported by processor	32 GB
Audio system	HD
Product type	Workstation
Motherboard chipset	Intel® C206
Memory slots	4x DIMM
Internal memory	4 GB
Memory channels	Dual-channel
Memory clock speed	1600 MHz
Memory layout (slots x size)	- GB
Resolution	2560 x 1440 pixels
Graphics card	Quadro 500M
Networking features	Gigabit Ethernet (10/100/1000)
Wireless technology	802.11 a/g/n
Graphics card family	NVIDIA
Maximum storage capacity	2 TB
HDD speed	7200 RPM
RAID levels	0, 1
HDD capacity	1000 GB
HDD interface	SATA
Optical drive type	DVD Super Multi
Maximum graphics card memory	1.024 GB
On-board graphics card model	Intel® HD Graphics P3000
On-board graphics card family	Intel® HD Graphics
On-board graphics card base frequency	850 MHz
On-board graphics card dynamic frequency (max)	1350 MHz
Number of displays supported (on-board graphics)	2
Display diagonal	27 \
Display number of colors	1.073 billion colors
Modem (RJ-11) ports	0
USB 2.0 ports quantity	7
Bundled software	Roxio Easy Media Creator; Intervideo WinDVD
Operating system installed	Windows 7 Professional
Power supply	400 W
Power supply input voltage	100 - 240 V
Power supply input frequency	50 - 60 Hz
Certification	Energy Star
Product color	Black
Country of origin	China
Processor code	SR00L
Processor ARK ID	52274
Processor package size	37.5 x 37.5 mm
Supported instruction sets	AVX
Intel Identity Protection Technology version	1.00

Weight and Dimensions

Depth	419.1 mm
Width	660.4 mm
Height	584.2 mm
Weight	213.2 g