HP 127695-B21 - Smart Array 431 RAID Controller Скачать руководство пользователя страница 4

Smart Array Controller Technology: Drive Array Expansion and Extension 

 

logical drive 
creation 

 

Once the drive capacity has been expanded, the added capacity can be 

used to create a new logical drive (figure 2) or to extend the size of an existing 
logical drive (as described in the section titled 

volume extension)

 

 

Some people might want to add a new logical drive, for example, if every 

department in a company had its own logical storage volumes. If a new 
department were created, the administrator might need to create an entirely 

new logical drive for that department, or need to improve performance of an 

existing volume by increasing the number of spindles (drives).  

 

 

figure 2. After capacity expansion, an administrator can use this free space by creating 
an entirely new logical drive

 

 

 

 

 

However, most customers will choose to extend the size of their volume after 

capacity expansion. The volume extension allows customers to increase the 

logical volume size if they are running out of storage space on the existing 
volume.  

Содержание 127695-B21 - Smart Array 431 RAID Controller

Страница 1: ... october 2002 hp industry standard servers technology brief abstract 2 introduction 2 array configuration utility 2 capacity expansion 3 logical drive creation 4 volume extension 5 volume extension in Windows 6 RAID migration 7 stripe size migration 8 conclusion 8 feedback 9 glossary 9 1 ...

Страница 2: ...nces between the two terms As a result customers sometimes find it difficult to distinguish between the two This paper presents a brief explanation of capacity expansion and volume extension The paper also briefly discusses other changes that an administrator might want to make such as RAID level migration and stripe size migration This paper assumes that the reader is familiar with basic array co...

Страница 3: ...Thus if an existing array is nearly filled with logical drives an administrator can add new physical drives and initiate a capacity expansion through ACU or ACU XE The program automatically checks the drive hardware configuration Then the existing logical drive is distributed across all physical drives in the expanded array without affecting any existing data If the array being expanded contains m...

Страница 4: ... had its own logical storage volumes If a new department were created the administrator might need to create an entirely new logical drive for that department or need to improve performance of an existing volume by increasing the number of spindles drives figure 2 After capacity expansion an administrator can use this free space by creating an entirely new logical drive However most customers will...

Страница 5: ... capacity expansion as previously discussed or by deleting another logical drive on the same array figure 3 Volume extension grows the size of a logical drive Unlike capacity expansion the OS must be aware of changes to the logical drive size The following operating systems support online volume extension Microsoft Windows 2000 NT 4 0 Novell NetWare 4 2 5 x SCO UnixWare 7 1 x Offline volume extens...

Страница 6: ...t be careful when performing volume extension on a dynamic drive The best way to grow a volume size in Windows 2000 is to take advantage of this dynamic disk functionality rather than performing a volume extension in ACU or ACU XE Because a dynamic disk can span multiple partitions on separate logical drives an administrator can create a completely new logical drive when free space exists Then the...

Страница 7: ...96 Usable drive space formula n n 2 n 1 n n 2 n Minimum number of drives 1 2 3 4 Tolerant of single drive failure No Yes Yes Yes Tolerant of multiple simultaneous drive failures No If failed drives not mirrored to each other No yes Read performance High High High High Write performance High Medium Low Low Relative cost Low High Medium medium The values for usable drive space are calculated assumin...

Страница 8: ...f server applications An administrator can take these general recommendations and try progressively larger or smaller stripe sizes to determine the best overall performance for a particular application Through ACU or ACU XE the administrator can make these changes online without disruption or data loss table 3 Recommended stripe sizes Type of Server Application Suggested Stripe Size Change Mixed r...

Страница 9: ...adding additional partitions Expansion The process of adding a physical drive to an existing array The logical drives that exist on the array before the expansion takes place are unchanged Only the amount of free space on the array changes Extension The process of growing the size of a logical drive In this case the size of the logical drive reported to the OS is increased Free space Blocks on an ...

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