Re: ld vs. dkctl in netbsd-8
Louis Guillaume <[email protected]>
| Newsgroups | gmane.os.netbsd.ports.i386 |
|---|---|
| Message-ID | <[email protected]> |
On 11/29/18 4:05 AM, David Brownlee wrote: > On Thu, 29 Nov 2018 at 09:00, Louis Guillaume <[email protected]> wrote: >> >> I just noticed this message in the console after a reboot: >> >> raid2: get cache for component /dev/dk1 failed >> >> which is a bit troubling, considering I didn't get a similar message for >> dk0, which is the other half of that raid1 pair (on raidframe). >> >> These drives are on separate (slightly different) twa controllers, using >> the ld driver. I recently updated this driver due to MP_SAFE crashes by >> applying the patch in this PR (the latest patch)... >> >> http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=53628 >> >> Here's an excerpt from the dmesg. Is this cache discrepancy a potential >> performance hit or should I be otherwise concerned? >> >> Any thoughts or help would be great. > > As an empirical check I'd be inclined to perform some write tests to a > filesystem on the RAID and see if the disks report similar time > utilisation from 'iostat -x 5'. > Probably just dd'ing /dev/zero to a file would be fine, though you > could also run a disk test like bonnie++. > > David > Below are some test results from bonnie++. Seems there is some big discrepancy on "intelligent" writes, but not as drastic on "rewrites". dk1 and dk3 are the raidframe components for "raid2". dk8 is a wedge on raid2, and it is used as an LVM PV, which contains the filesystem on which bonnie is being run. Thanks for looking! -- Louis # iostat -x 20 |awk 'NR==1||/dk[138]/' & [1] 17096 16275 # device read KB/t r/s time MB/s write KB/t w/s time MB/s dk1 26.43 18 0.03 0.46 30.76 32 0.03 0.96 dk3 27.53 18 0.02 0.48 30.76 32 0.02 0.96 dk8 44.36 22 0.04 0.93 57.55 14 0.04 0.76 # bonnie++ -u louis -d . Using uid:1000, gid:100. Writing a byte at a time... dk1 0.00 0 0.00 0.00 19.21 6 0.00 0.11 dk3 0.00 0 0.00 0.00 19.21 6 0.00 0.11 dk8 0.00 0 0.02 0.00 27.45 3 0.02 0.08 dk1 0.00 0 0.00 0.00 23.54 4 0.00 0.09 dk3 0.00 0 0.00 0.00 23.54 4 0.00 0.09 dk8 0.00 0 0.00 0.00 35.08 3 0.00 0.09 done Writing intelligently... dk1 20.00 0 0.25 0.00 31.93 1142 0.25 35.60 dk3 0.00 0 0.46 0.00 31.93 1141 0.46 35.58 dk8 20.00 0 0.62 0.00 63.73 571 0.62 35.55 dk1 0.00 0 0.30 0.00 31.96 1690 0.30 52.75 dk3 0.00 0 0.66 0.00 31.96 1691 0.66 52.77 dk8 0.00 0 0.89 0.00 63.79 848 0.89 52.80 dk1 26.40 0 0.19 0.01 31.92 1202 0.19 37.45 dk3 0.00 0 0.36 0.00 31.92 1201 0.36 37.43 dk8 26.40 0 0.59 0.01 63.63 602 0.59 37.41 dk1 28.89 0 0.36 0.01 31.94 1649 0.36 51.43 dk3 30.86 0 0.47 0.01 31.94 1650 0.47 51.46 dk8 29.75 1 0.87 0.02 63.75 827 0.87 51.47 done Rewriting... dk1 32.00 184 0.51 5.75 31.93 1244 0.51 38.78 dk3 32.00 192 0.55 6.00 31.93 1243 0.55 38.77 dk8 63.82 188 0.89 11.75 63.68 624 0.89 38.78 dk1 31.99 430 0.70 13.44 31.94 883 0.70 27.55 dk3 31.99 451 0.74 14.10 31.94 884 0.74 27.56 dk8 63.93 441 0.94 27.53 63.71 443 0.94 27.54 dk1 31.97 429 0.74 13.40 31.94 887 0.74 27.66 dk3 31.99 455 0.66 14.22 31.94 886 0.66 27.65 dk8 63.97 442 0.95 27.62 63.75 444 0.95 27.66 dk1 32.00 435 0.77 13.60 31.88 906 0.77 28.20 dk3 32.00 464 0.65 14.50 31.88 906 0.65 28.20 dk8 63.97 450 0.96 28.11 63.52 454 0.96 28.18 dk1 32.00 457 0.73 14.28 31.94 934 0.73 29.15 dk3 32.00 475 0.72 14.84 31.94 934 0.72 29.14 dk8 63.97 466 0.95 29.12 63.71 469 0.95 29.15 dk1 32.00 407 0.72 12.73 31.98 852 0.72 26.62 dk3 32.00 444 0.72 13.88 31.98 852 0.72 26.62 dk8 63.96 426 0.94 26.61 63.86 427 0.94 26.62 dk1 31.97 407 0.72 12.70 31.89 829 0.72 25.83 dk3 31.98 419 0.67 13.10 31.89 829 0.67 25.82 dk8 63.83 414 0.96 25.80 63.52 416 0.96 25.80 dk1 32.00 390 0.67 12.20 31.92 801 0.67 24.96 dk3 32.00 407 0.71 12.73 31.92 801 0.71 24.96 dk8 63.95 399 0.96 24.93 63.62 402 0.96 24.96 done Reading a byte at a time... done Reading intelligently... dk1 32.00 645 0.38 20.14 31.81 105 0.38 3.25 dk3 32.00 682 0.37 21.33 31.81 105 0.37 3.26 dk8 63.41 669 0.49 41.46 63.12 53 0.49 3.26 dk1 32.00 1247 0.72 38.97 11.00 0 0.72 0.00 dk3 32.00 1611 0.62 50.35 11.00 0 0.62 0.00 dk8 63.30 1445 0.86 89.34 13.10 0 0.86 0.00 done start 'em... dk1 32.00 1183 0.62 36.97 14.39 0 0.62 0.01 dk3 32.00 1283 0.57 40.08 14.39 0 0.57 0.01 dk8 63.21 1248 0.75 77.04 16.19 0 0.75 0.01 dk1 31.94 64 0.86 2.00 15.42 4 0.86 0.07 dk3 31.87 67 0.80 2.09 15.42 4 0.80 0.07 dk8 31.94 131 0.98 4.08 16.90 3 0.98 0.05 done...done...done...done...done... Create files in sequential order... dk1 31.92 64 0.86 1.99 30.27 61 0.86 1.80 dk3 31.82 68 0.80 2.11 30.27 61 0.80 1.80 dk8 31.99 131 0.97 4.09 31.05 58 0.97 1.76 done. Stat files in sequential order...done. Delete files in sequential order...done. Create files in random order... done. Stat files in random order... done. Delete files in random order... done. Version 1.97 ------Sequential Output------ --Sequential Input- --Random- Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP xxxxxxxxxxxxxxxx 4G 70 96 49245 50 27616 28 334 99 93338 50 225.0 32 Latency 763ms 1039ms 351ms 40907us 129ms 481ms Version 1.97 ------Sequential Create------ --------Random Create-------- xxxxxxxxxxxxxxxx -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 2032 52 +++++ +++ 9557 84 3628 87 5041 100 5744 91 Latency 62918us 49us 7645us 1606us 463us 4138us 1.97,1.97,xxxxxxxxx,1,1543487070,4G,,70,96,49245,50,27616,28,334,99,93338,50,225.0,32,16,,,,,2032,52,+++++,+++,9557,84,3628,87,5041,100,5744,91,763ms,1039ms,351ms,40907us,129ms,481ms,62918us,49us,7645us,1606us,463us,4138us