Specifications

DS300f G2 Series User Manual
186
• Imaging applications
• Database servers
• Generalleserver
rAid 3 - block striPe And dedicAted PArity
RAID 3 organizes block data across multiple physical drives and parity data on a dedicated drive. Generally, RAID
Level 3 tends to exhibit lower random write performance due to the heavy workload of parity recalculation for each
I/O. Heavy I/O loads with a large number of writes tends to work the parity drive harder in proportion to the other
drives in the logical drive. ASUS Storage implements RAID 3 with block-level striping, rather than byte-level striping.
Advantages Disadvantages
•
Goodforlargeleswithhightransfer
rateswherefaulttoleranceisalso
required
• Randomwriteperformanceonlyfair.
Diskfailurehasamediumimpacton
throughput
Recommended Applications for RAID 3:
• Video editing
• Multimedia production
• File and application server
rAid 5 – block And PArity striPe
RAID 5 organizes block data and parity data across the physical drives. Generally, RAID Level 5 tends to
exhibit lower random write performance due to the heavy workload of parity recalculation for each I/O. RAID 5
isgenerallyconsideredtobethemostversatileRAIDlevel.Itworkswellforle,database,applicationandweb
servers.
The capacity of a RAID 5 logical drive equals the smallest physical drive times the number of physical drives,
minus one. Hence, a RAID 5 logical drive with four 100 GB physical drives has a capacity of 300 GB. A RAID 5
logical drive with two 120 GB physical drives and one 100 GB physical drive has a capacity of 200 GB.
RAID 5 is generally considered to be the most versatile RAID level.
A RAID 5 on ASUS DS300f G2 consists of 3 to 32 physical drives.
Advantages Disadvantages
•
HighReaddatatransactionrate
• MediumWritedatatransactionrate
• Goodaggregatetransferrate
• MostversatileRAIDlevel
• Diskfailurehasamediumimpacton
throughput
Recommended Applications for RAID 5:
• File and Application servers
• WWW, E-mail, and News servers
• Intranet servers
rAid 6 – block And double PArity striPe
RAID level 6 stores dual parity data is rotated across the physical drives along with the block data. A RAID 6
logical drive can continue to accept I/O requests when any two physical drives fail.
Hence, a RAID 6 logical drive with (7) 100 GB physical drives has a capacity of 500 GB. A RAID 6 logical drive
with (4) 100 GB physical drives has a capacity of 200 GB.
RAID6becomesmorecapacityefcientintermsofphysicaldrivesasthenumberofphysicaldrivesincreases.
RAID 6 provides double fault tolerance. Your logical drive remains available when up to two physical drives fail.
RAID 6 is generally considered to be the safest RAID level.
A RAID 6 on ASUS DS300f G2 consists of 4 to 32 physical drives.
Advantages Disadvantages
•
HighReaddatatransactionrate
• MediumWritedatatransactionrate
• Goodaggregatetransferrate
• SafestRAIDlevel,exceptforRAID60
• Highdiskoverhead–equivalentoftwodrivesused
forparity
• SlightlylowerperformancethanRAID5
Recommended Applications for RAID 6:
• Accounting and Financial
• Database servers
• Any application requiring very high availability
rAid 10 – Mirror + striPe