Dell R720xd,E5-2620*2,32GB RAM,PERC H720P Mini (LSI SAS2208 ROC)
	Red Hat Enterprise Linux Server release 6.3
	General Parallel File System (GPFS) 3.5.0.7
	SSD: Plextor M5pro 256GB
	Iozone 3.414,测试命令iozone -i 0 -i 1 -i 2 -r 1m -s 64G,结果单位Kbytes/sec
	说明:Dell PERC H720P是CacheCade 1.1,SSD只支持读缓存不支持写缓存
Raid1:2个2.5" SAS2 10Krpm 600GB组成Raid1,文件系统ext4
	无CacheCade
	write: 187650
	rewrite: 186938
	read: 175573
	reread: 176657
	random read: 70806
	random write: 130185
	有CacheCade
	write: 189204
	rewrite: 185290
	read: 174780
	reread: 175871
	random read: 95549
	random write: 129789
通过SSD缓存随机读取明显提升
Raid5:15个2.5" SAS2 10Krpm 900GB,每5个硬盘为一个Raid5共3个,每个Raid5在GPFS里面做成一个NSD,三个NSD做成一个GPFS文件系统
	无CacheCade
	write: 1017661
	rewrite: 1010487
	read: 1253673
	reread: 1371768
	random read: 103493
	random write: 504399
	有CacheCade
	write: 469138
	rewrite: 459371
	read: 559042
	reread: 566837
	random read: 53655
	random write: 362697
当SSD性能落后于被加速的机械硬盘时性能反而下降