linux 系统提速手记!（Linux system speed notes!）.docVIP

linux 系统提速手记!（Linux system speed notes!） First, open the hard disk DMA support. After the system is installed, the DMA of the hard disk is not opened The /etc/rc.d/rc.local ends with a line of /sbin/hdparm -d1 -c3 -m16 /dev/hda, so after each boot, the DMA of the hard disk is turned on without having to manually set it every time. If the hard disk machine you can add -X66 support to ATA33 ATA66 this parameter is -X68, I like the hard disk is ATA66 that is /sbin/hdparm -d1 -X68 -c3 parameters of -m16 /dev/hda after my test, before DMA is not open, the actual reading efficiency is about 4.10 Mb per second, after opening DMA, the actual reading efficiency per second jumped to about 20 Mb increased by 5 times. The DMA test is not open [root@firefly, /root]#, hdparm, -d0, /dev/hda /dev/hda: Setting using_dma to 0 (off) Using_dma = 0 (off) [root@firefly, /root]#, hdparm, -Tt, /dev/hda /dev/hda: Timing, buffer-cache, reads: 128, MB, in 2.75, seconds = 46.55, MB/sec Timing, buffered, disk, reads:, 64, MB, in, 15.58, seconds = 4.11, MB/sec The open test results after DMA [root@firefly, /root]#, hdparm, -d1, -X68, -c3, -m16, /dev/hda /dev/hda: Setting, 32-bit, I/O, support, flag, to, 3 Setting multcount to 16 Setting using_dma to 1 (on) Setting xfermode to 69 (UltraDMA mode5) Multcount = 16 (on) I/O support = 3 (32-bit, w/sync) Using_dma = 1 (on) [root@firefly, /root]#, hdparm, -Tt, /dev/hda/dev/hda: Timing, buffer-cache, reads: 128, MB, in 2.75, seconds = 46.55, MB/sec Timing, buffered, disk, reads:, 64, MB, in, 3.20, seconds = 20, MB/sec From the above data, we can see whether the hard disk DMA is open or not, which has a great impact on the reading efficiency. Two, turn off redundant system services. This is the topic of the general a commonplace talk of an old scholar, we as a desktop workstation, just need to activate several basic Service? Can others not only useless, on the one hand will take up system resources, on the other hand, there will be security concerns, I us