提高预读缓存的大小是否有任何缺点？

在我们的农场,我们目前运行在256,并且在提高了这一点后,我们看到了显着的吞吐量增长.

[root@server~]# hdparm -tT /dev/sda /dev/sda: 
Timing cached reads: 7352 MB in 2.00 seconds = 3677.62 MB/sec 3
Timing buffered disk reads: 244 MB in 3.10 seconds = 78.68 MB/sec 

[root@server ~]# blockdev --setra 10240 /dev/sda 

[root@server ~]# hdparm -tT /dev/sda /dev/sda: 
Timing cached reads: 11452 MB in 2.00 seconds = 5728.52 MB/sec 
Timing buffered disk reads: 422 MB in 3.17 seconds = 133.04 MB/sec

我们正在运行2.6.谢谢！