> iostat -cxnz 1 201 gives the following indication: > > cpu > us sy wt id > 22 78 0 0 > extended device statistics > r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device > 0.0 43.0 0.0 159.5 0.0 0.1 0.1 2.3 0 10 c1d0 > 0.0 43.0 0.0 159.5 0.0 0.1 0.1 2.0 0 8 c2d0
What is your exact system setup, and what test are you running? > So, I guess that the high cpu usage combined with low > disk utilization (%b) could indicate something, > right? Am I looking at kernel driver issues or what? > I'm using an Asus M2NPV-VM motherboard with an Nforce > chipset. Well, I have the same Asus M2NPV-VM mainboard, and a zfs mirrored poll with two S-ATA drives: % zpool status files pool: files state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM files ONLINE 0 0 0 mirror ONLINE 0 0 0 c4d0s6 ONLINE 0 0 0 c5d0s6 ONLINE 0 0 0 errors: No known data errors Creating a 4.8GB file on that zpool with... % time mkfile 4800m foobar 0.01u 2.51s 0:04.46 56.5% ... shows iostat rates that are similar with the numbers you've got: us sy wt id 1 54 0 44 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 103.1 0.0 365.8 0.1 0.1 0.8 1.2 1 11 c4d0 0.0 100.1 0.0 365.8 0.1 0.2 1.0 1.5 2 13 c5d0 cpu us sy wt id 0 64 0 35 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 0.0 99.1 0.0 378.2 0.1 0.1 0.6 1.2 1 11 c4d0 0.0 98.1 0.0 377.2 0.1 0.1 0.6 1.3 1 12 c5d0 The "mistake" with this "benchmark" is that zfs compresses away all the null bytes; not that the file consumes just a single disk block, although it has a file size of 4.8gbytes: % du -h foobar 0K foobar % du foobar 1 foobar % ls -l foobar -rw------- 1 jk usr 5033164800 Apr 3 11:16 foobar All that zfs has to write are a few file metadata updates (modification time updates, file size updates), and that results in a few hundred kilobytes written to disk per seconds. Note also, that when you compute the number of bytes written per second by mkfile you get a transfer rate at the filesytem level of > 1 gbyte/sec! % bc scale=3 5033164800/4.46 1128512286.995 If you want to measure / verify SATA performace, run the "iostat -cxnz 1 201" command in a window, and at the same time read from the raw disk device, using something like dd if=/dev/rdsk/c1d0p0 of=/dev/null bs=32k When I run such a test on the Asus M2NPV-VM, I see cpu us sy wt id 1 12 0 87 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 2407.0 0.0 77024.6 0.0 0.0 0.8 0.0 0.3 4 84 c4d0 cpu us sy wt id 0 11 0 88 extended device statistics r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device 2427.0 0.0 77664.3 0.0 0.0 0.8 0.0 0.3 4 85 c4d0 This message posted from opensolaris.org _______________________________________________ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org