I'm doing som data-mining on a pile of ISO images right now. I stuck the ISOs on a UFS2 on a flash-disk for speed, and mdconfig(8)'d them so I could mount them. The traffic pattern his "interesting": dT: 1.003s w: 1.000s L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name [...] 1 733 733 1466 1.3 0 0 0.0 98.2| md39 1 733 733 23449 1.3 0 0 0.0 93.2| da0 Notice the 1:16 ratio on kBps but 1:1 ratio on ops/s ? da0's UFS2 has 32k block-size: magic 19540119 (UFS2) time Wed Jan 4 16:41:47 2012 superblock location 65536 id [ 4f046cf5 c30697ee ] ncg 104 size 19537685 blocks 19228156 bsize 32768 shift 15 mask 0xffff8000 fsize 4096 shift 12 mask 0xfffff000 [...] It looks like every 2k read from CD9660 turns into a 32k block read in the UFS filesystem, without any beneficial caching happening. Less than optimal I'd say... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk_at_FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.Received on Sun Jan 08 2012 - 21:21:52 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:23 UTC