Dell PowerVault MD3000i - Manual (Page 15)

Dell™ PowerVault MD3000 and MD3000i Array Tuning Best Practices
December 2008 – Revision A01 Page 15
4.7.3 I/O Distribution
I/O can be characterized by its distribution and pattern. The two primary factors
in determining the I/O distribution of an application are the randomness of I/O
and the direction of I/O. The randomness of I/O indicates how sequential or
random the data access is, as well as the patterning of this data access. The
direction of the I/O can be simply related to the read and write percentages of
I/O, that is, the direction I/O is taking from the storage device. I/O pattern refers
Volume 0 Attributes:
Volume Type: RAIDVolume
User Label: MyRAID10_One
...
BlockSize: 512 bytes
LargeIoSize: 4096 blocks
...
Perf. Stats: Requests Blocks Avg. Blks IO Percent
Reads 67456452 5943724625 88 71.20%
Writes 27283249 1144902648 41 28.80%
Large Reads 0 0 0 0.00%
Large Writes 0 0 0 0.00%
Total 94739701 7088627273 74 100.00%
Figure 3: Second Generation Firmware - RAID Level. File: stateCaptureData.txt
Virtual Disk Unit 0 Configuration
Volume Type: 13+1 RAID 5
User Label: MyRAID5_1
Block Size: 512 bytes
Large IO: 4096 blocks
Segment Size: 256 blocks
Stripe Size: 3328 blocks
...
IO Statistics:
small small large large cache
reads writes reads writes total hits
requests 2028332119 147699066 0 0 2176031185 1289775370
blocks 3091968111 2518067526 0 0 1315068341 4019884678
avg blocks 4 17 0 0 0 3
IO pct. 93.21% 6.78% 0.00% 0.00% 0.00% 59.27%
IOs stripes /IO clusters /IO
reads 2028332119 2034477363 1.00 2107869128 1.03
writes 147699066 148449472 1.00 157404718 1.06
write Full Partial RMW No Parity RMW2 FSWT
algorithms 1105611 12598366 32120072 0 0 0
Figure 2: First Generation Firmware - RAID Level. File: stateCaptureData.txt