9 | | <p><b>XFS: A high-performance journaling filesystem</b></p> |
10 | | <a href='http://oss.sgi.com/projects/xfs/'>http://oss.sgi.com/projects/xfs/</a><p/> |
11 | | <b>Filesystem Block Size</b><p/> |
12 | | <u>The minimum filesystem block size is 512 bytes. <b>The maximum filesystem block size is the page size of the kernel</b>, which is 4K on x86 architecture and is set as a kernel compile option on the IA64 architecture (up to 64 kilobyte pages).</u> So, XFS supports filesystem block sizes up to 64 kilobytes (from 512 bytes, in powers of 2), when the kernel page size allows it. |
| 10 | <p><b>XFS: A high-performance journaling filesystem</b><br/> |
| 11 | <a href='http://oss.sgi.com/projects/xfs/'>http://oss.sgi.com/projects/xfs/</a><br/> |
| 12 | <b>Filesystem Block Size</b><br/> |
| 13 | <u>The minimum filesystem block size is 512 bytes. <b><font color='red'>The maximum filesystem block size is the page size of the kernel</font></b>, which is 4K on x86 architecture and is set as a kernel compile option on the IA64 architecture (up to 64 kilobyte pages).</u> So, XFS supports filesystem block sizes up to 64 kilobytes (from 512 bytes, in powers of 2), when the kernel page size allows it.</p> |
30 | | * [參考三] [ |
| 32 | * 那如何查出目前的 Kernel Page Size 呢? |
| 33 | * [參考三] [http://www.cyberciti.biz/faq/linux-check-the-size-of-pagesize/ Linux Find Out Virtual Memory PAGESIZE] |
| 34 | {{{ |
| 35 | ~$ getconf PAGESIZE |
| 36 | OR |
| 37 | ~$ getconf PAGE_SIZE |
| 38 | }}} |
| 39 | * 結論(3):'''除了加大 Block Size 之外,最常用的方式是啟動 read ahead (運用快取來提昇硬碟循序讀取的效率)''' |
| 40 | * [參考四] [http://forums.opensuse.org/forums/english/get-technical-help-here/install-boot-login/437078-changing-pagesize-kernel.html#post2152312 Changing PAGESIZE in kernel] |
| 41 | {{{ |
| 42 | #!text |
| 43 | AIX vio ioo is a read ahead cache system to improve speed of transfers when doing sequential reads. |
| 44 | }}} |
| 45 | * [參考五] [http://www.linuxpinguin.de/2011/01/performance-increase-through-bigger-readahead-buffers/ Performance increase through bigger readahead buffers] - 以下示範是把預設的 RA 由 256 提升到 1024 |
| 46 | {{{ |
| 47 | ~$ blockdev --report |
| 48 | RO RA SSZ BSZ 起始磁區 大小 裝置 |
| 49 | rw 256 512 4096 0 500107862016 /dev/sda |
| 50 | rw 256 512 4096 2048 497999151104 /dev/sda1 |
| 51 | rw 256 512 4096 972656640 2106589184 /dev/sda2 |
| 52 | ~$ sudo blockdev --setra 1024 /dev/sda1 |
| 53 | }}} |