HP AutoRAID 12H Скачать руководство пользователя страница 11

section 1 

The HP Virtual Array accepts new disks while 
the array is up and running and accepting I/Os 
as with some higher-end traditional arrays. 
However, the HP Virtual Array takes it one step 
further. Once the disk is inserted, the array 
automatically includes that disk into the existing 
disk space and stripes all LUNs across that disk. 
This means that even without the creation of any 
additional LUNs, the array performance will 
improve because of the additional available 
spindle. Only the HP Virtual Array automatically 
adds the new disks to existing LUNs. Further, 
any newly created LUNs are also automatically 
spread across all the disks in the array, including 
the additional disk. 

time to implementation: 
formatting the array 

As mentioned earlier, after new disks are added 
to a traditional array, it then takes several hours 
to complete the formatting of the RAID group. 
During this format phase, no data can be written 
to the new LUNs. With some implementations, 
the array is offline until all the LUNs have been 
formatted. In other implementations, I/Os can 
be written to already formatted LUNs even while 
other LUNs are going through the format 
process, although performance is very slow. 

Because executing the disk format command 
uses up so much of the array’s internal bandwidth, 
array performance is greatly reduced until all 
of the disk formatting has been completed. 
With HP’s Virtual Array Technology, the array is 
immediately available as soon as the LUNs have 
been configured. The disk formatting is done as 
the writes are done. In other words, as writes 
are sent to disk, the formatting is accomplished 
for only those blocks being written to. This means 
that while there is a small hit to performance for 
that individual write, there is very, very little 
impact on overall array performance. 

automating the cache 
parameters 

1

Configuring a traditional array typically requires 
setting the cache parameters such as the percentage 
of read and write cache, the size of the cache 
pages, and, in some cases, the allocation of cache 
to specific LUNs. In making these determinations, 
there is ample opportunity for error. 

With HP’s Virtual Arrays, all of this is preset and 
automatic. And this means that all the parameters 
within the array are tuned to work in unison with 
the stripe size and the array hardware. First, the 
cache is set at 80% read and 20% write, is 
shared between controllers, and is treated as a 
“pool.” Second, the cache page size is set at 
64K and is set to automatically destage to disk 
every 4 seconds whether the page is full or not. 
The 64K size minimizes the number of I/Os to 
the back-end in sequential environments and 
provides a carefully calculated balance within the 
array between the number of cache pages and the 
speed of the back-end in random environments. 

performance 

Traditional arrays are susceptible to “hot spots” and 
to changes in the environment that make the initial 
configuration obsolete. The HP Virtual Array virtually 
eliminates these critical performance issues. 

First, the HP Virtual Array is far less likely to 
experience a hot spot—in other words, it will 
almost never experience a condition where a 
few disk drives become a performance bottleneck 
in the array. Here’s why: the virtual array 
always (and automatically) stripes all of the 
LUNs across all of the disks in the RAID group. 
For example: assume a virtual array loaded with 
a total of 60 disks had 30 disks in each of its 
two RAID/redundancy groups. Every LUN in 
that group would be spread across all 30 disks. 

1.5

hp storage white paper 

Содержание AutoRAID 12H

Страница 1: ...hp virtual array double your operating efficiency ...

Страница 2: ... printing industry with its industry leading LaserJet printers Now HP s Virtual Arrays are revolutionizing the storage industry creating industry leading storage solutions that save your organization 2x in operating costs over the current set of arrays on today s market HP s Virtual Arrays are automated to maximize your operating efficiencies and maximize your return on investment They are automat...

Страница 3: ...ional storage 1 2 configuring an array for a database 1 3 the system administrator s dilemma 1 4 managing the hp virtual array 1 4 adding capacity with hp virtual arrays 1 4 time to implementation formatting the array 1 5 automating the cache parameters 1 5 performance 1 5 faqs 1 6 summary 1 8 for more information 1 8 section 2 hp extends virtualization to the array by D H Brown Associates Inc Nov...

Страница 4: ...d a VA7100 for our SAN We found the set up to be fast and easy and the performance excellent It was an easy decision to add a second virtual array a VA7400 to accommodate our growth and position us for the future John Focht Systems Administrator Room Board State of New Mexico In consolidating from eight controllers to the HP Surestore VA7100 we expected to see some performance degradation in runni...

Страница 5: ...olution with HP Gary Davis Hospital Information Systems Manager II Santa Clara ViaSat We selected the HP Surestore Virtual Array 7400 storage based on the number of Oracle ERP instances that would be needed We found the Virtual Array has many more features and capabilities than the Sun solution that was being proposed We felt it would scale the way we needed provided strong price performance and o...

Страница 6: ...ge with less effort reduces the opportunities for human error frees up precious IT resources to work on revenue generating projects self manages the RAID configuration for optimum performance array virtualization defined The purpose of virtualization in any technology is to hide complexity from the user or in the case of disk arrays to hide complexity from the storage administrator and provide a s...

Страница 7: ...man head count doesn t virtualization reduces the number of people required to manage storage key features of hp s patented virtual technology automatically stripes every LUN across all disks in a very large redundancy group Benefit simplifies overall management reduces the number of LUNs required to hot spots 1 automatically adds new disk drives into existing RAID groups Benefit capacity upgrades...

Страница 8: ... better management software environments are encouraged to add more hardware and eventually the environment becomes as complex as it was before but for different reasons And when the human resources are already stretched to the breaking point this is a recipe for complexity stress long hours and human error Virtualization is the answer It solves the basic underlying problem It permanently simplifi...

Страница 9: ...ents for each of the pieces and they don t know the performance behavior of the array in its multitude of configurations In these real world environments it is typically far too time consuming to try a number of different storage configurations so database administrators typically apply rules from previous installations The changing characteristics of newer versions of the database typically resul...

Страница 10: ...of determining the total capacity and performance requirements for each application determining the number and size of LUNs for the necessary performance 1 Step away from the array the configuration is now complete Every other step is automatic RAID levels are automatic The different capacity number and speeds of disk drives are automatically accounted for The cache page size is automatically set ...

Страница 11: ...that while there is a small hit to performance for that individual write there is very very little impact on overall array performance automating the cache parameters 1 Configuring a traditional array typically requires setting the cache parameters such as the percentage of read and write cache the size of the cache pages and in some cases the allocation of cache to specific LUNs In making these d...

Страница 12: ...lso has the best availability of any mid range array on the market See the white paper titled VA7100 Hardware High Availability Features 1 Short answer Both the HP Surestore Virtual Array 7100 and the HP Surestore Virtual Array 7400 can be configured to run in either fixed RAID 1 0 or AutoRAID modes And to help with performance analysis the controller can provide data on the actual usage of each R...

Страница 13: ...and go through a time consuming and complex reconfiguration every time the 1 hours per day It is the hands down winner in real world performance A better analogy would be to compare the multiple manual processes required to set the type load the paper and actually print books on the old style printing presses with those of the automated printing systems of our generation Obviously automation in pr...

Страница 14: ...e as good as in any manually configured array And don t forget if the environment should change after that even slightly the HP Virtual Array will adjust while a manually configured array can do nothing but keep plugging along in a degraded mode Question Are you saying that this technology is for everyone I m not looking for anything new Answer If it s new to you then it is understandable that HP ...

Страница 15: ... at the device level HP s VA7000 Series Characteristics Feature VA7100 VA7400 Capacity 1 TB raw in 3U enclosure 14 TB in 2M rack 7 6 TB raw using the Disk System DS 2400 up to six DS2400s chained 14 TB in a 2M rack of 73 GB disks LUNs max 128 1 024 Disk Drives Supported 15 per 3U enclosure same disk support as 7400 Up to 105 drives with DS2400 18 GB 15 K rpm 36 GB 10 K and 15 K rpm and 73 GB 10 K ...

Страница 16: ...sks block level rather than in disk sized chunks The impact of free space management and garbage collection is absorbed at the array level without consuming SAN or server resources super redundancy enhances RAID 2 As alternatives to the self tuning LUN management capability described above the VA7000 series also enhances LUN performance through its use of RAID configurations redundancy groups Many...

Страница 17: ... Controller to controller communication and loop failover occur via an internal N way bus The VA7400 supports two redundancy groups in which onecontrollermanagesaccesstooneredundancy group consisting of all the odd numbered disk slots and the other controller to the second group 2 as in the VA7100 The variation in data management at the array level provides great flexibility in matching performanc...

Страница 18: ...h Intel Pentium III 500 MHz computers or above supports 128 World Wide Names and 128 secure LUNs HP UX with all PA RISC computers Windows and Linux with Intel Pentium III 500 MHz computers or above Managed by Command View SDM supports 128 World Wide Names and 1 024 secure LUNs Business Copy VA HP UX with all PA RISC computers Windows and Linux with Intel Pentium III 500 MHz computers or above supp...

Страница 19: ... ability to self configure and to automatically manage multiple I O paths It also provides dynamic load balancing to ensure peak performance This document is copyrighted by D H Brown Associates Inc DHBA and is protected by U S and international copyright laws and conventions This document may not be copied reproduced stored in a retrieval system transmitted in any form posted on a public or privat...

Страница 20: ...06 02 5981 2067ENUC ...

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