Hi > take a look at the following output of iostat -xzn 5: > extended device statistics > r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device > 119.4 0.0 11014.2 0.0 0.0 1.7 0.0 13.9 0 96 md/d10 > 59.6 0.0 5529.4 0.0 0.0 0.9 0.0 14.4 0 72 md/d11 > 59.8 0.0 5484.8 0.0 0.0 0.8 0.0 13.4 0 70 md/d12 > 0.4 169.2 3.2 11143.8 0.0 1.5 0.0 8.6 0 52 md/d20 > 0.2 169.2 1.6 11143.8 0.0 1.1 0.0 6.5 0 38 md/d21 > 0.2 169.2 1.6 11143.8 0.0 1.0 0.0 6.2 0 38 md/d22 > 59.8 173.2 5531.0 11145.8 0.0 2.0 0.0 8.4 0 77 c0t0d0 > 60.0 169.2 5486.4 11143.8 0.0 1.8 0.0 8.0 0 78 c13t0d0 > > d10 consists of d11 and d12 > d20 consists of d21 and d22 > > So how is it possible that reads of d11,d12 sum up in d10, but writes of d20, > d21, and d22 are all equal. Is this a bug? > > This occurred during 'lumake -n slice1' on: > $ uname -a > SunOS azalin 5.10 Generic_127111-01 sun4u sparc SUNW,Sun-Blade-2500 > > Any comments?
Assuming that d10 and d20 are mirror devices with two sub mirrors each... Reads to such devices are handled round robin by default so the total read from the metadevice will be the sum of all submirrors. Of course for writes whatever you dump into d20 shows up on each of the submirrors Thomas ----------------------------------------------------------------- GPG fingerprint: B1 EE D2 39 2C 82 26 DA A5 4D E0 50 35 75 9E ED _______________________________________________ opensolaris-discuss mailing list [email protected]
