<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Feb 12, 2014 at 10:55 AM, Saso Kiselkov <span dir="ltr"><<a href="mailto:skiselkov.ml@gmail.com" target="_blank">skiselkov.ml@gmail.com</a>></span> wrote:<br>
<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Can you also try running this piece of dtrace on the machine? I have a<br>
hypothesis that I'd like to test:<br>
<br>
dtrace -n 'fbt::l2arc_evict:entry{printf("dev=%p; l2ad_first=%d",<br>
args[0], args[0]->l2ad_first)}'<br>
<br>
(let it run for about 5-10s and post the output)<br></blockquote><div> </div><div><br></div><div>Output from the above dtrace:<br><br>dtrace: description 'fbt::l2arc_evict:entry' matched 1 probe<br>CPU ID FUNCTION:NAME<br>
12 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 12 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 12 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br>
14 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 0 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 5 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br>
5 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 19 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br>
21 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 23 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 0 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br>
11 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 13 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 14 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br>
15 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 19 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br>
3 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 3 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 3 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br>
3 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 16 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 3 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br>
13 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 3 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 0 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br>
21 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 2 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 18 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br>
1 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br>
2 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 2 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 2 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br>
20 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 0 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 0 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br>
0 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> 2 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br>
0 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 8 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br> 1 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br>
4 40955 l2arc_evict:entry dev=ffffff4377e25058; l2ad_first=1<br> 14 40955 l2arc_evict:entry dev=ffffff4377e25148; l2ad_first=1<br> 12 40955 l2arc_evict:entry dev=ffffff432153be68; l2ad_first=1<br>
21 40955 l2arc_evict:entry dev=ffffff43782a8240; l2ad_first=1<br> <br></div><div>And on your other question:<br><br>> What's the block size of your SSDs and the average recordsize of the<br>> data on them?<br>
<br></div><div>I'm actually not sure what you're asking about.. the recordsize on the pool itself? It's 128K. I have different volblocksize on various volumes. Or information about the SSD itself?<br><br>* /dev/rdsk/c2t500117310015D579d0 partition map<br>
*<br>* Dimensions:<br>* 512 bytes/sector<br>* 781422768 sectors<br>* 781422701 accessible sectors<br>*<br>* Flags:<br>* 1: unmountable<br>* 10: read-only<br>*<br>* Unallocated space:<br>* First Sector Last<br>
* Sector Count Sector<br>* 34 222 255<br>*<br>* First Sector Last<br>* Partition Tag Flags Sector Count Sector Mount Directory<br> 0 4 00 256 781406095 781406350<br>
8 11 00 781406351 16384 781422734<br></div></div></div></div>