For an new IMGate client, I've sold him an IMGate box with two ATA100,
7200RPM disks, connected to the mobo ATA0 and ATA1:
ad0: 19470MB <IC35L020AVVA07-0> [39560/16/63] at ata0-master UDMA100
ad2: 19470MB <IC35L020AVVA07-0> [39560/16/63] at ata1-master UDMA100
I've setup the second disk as /var2, for a dedicated /var2/spool/postfix
mailqueue, leaving the first disk for /var/log logging.
sending 10k msgs of 25k each through the machine, here's how the i/o is
distributed:
mx1# iostat -c 50
tty ad0 ad2 md0 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
1 317 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 4 0 5 1 91
0 76 0.00 0 0.00 12.82 102 1.28 0.00 0 0.00 14 0 15 2 70
0 76 0.00 0 0.00 12.94 63 0.80 0.00 0 0.00 5 0 15 0 80
0 76 0.00 0 0.00 13.05 44 0.56 0.00 0 0.00 7 0 10 1 82
0 76 0.00 0 0.00 13.11 125 1.60 0.00 0 0.00 12 0 22 3 63
0 76 0.00 0 0.00 12.56 95 1.17 0.00 0 0.00 11 0 16 2 71
0 76 16.00 3 0.05 12.71 55 0.69 0.00 0 0.00 2 0 10 1 87
0 76 16.00 3 0.05 13.32 81 1.06 0.00 0 0.00 12 0 12 2 74
0 76 56.00 2 0.11 11.76 81 0.93 0.00 0 0.00 15 0 10 1 74
0 76 0.00 0 0.00 11.34 168 1.86 0.00 0 0.00 12 0 8 3 77
0 76 0.00 0 0.00 12.87 66 0.83 0.00 0 0.00 10 0 10 4 76
0 76 0.00 0 0.00 12.80 81 1.02 0.00 0 0.00 9 0 12 2 78
0 76 48.00 1 0.05 13.15 145 1.86 0.00 0 0.00 19 0 22 1 59
0 76 0.00 0 0.00 13.11 27 0.34 0.00 0 0.00 2 0 7 1 90
0 76 0.00 0 0.00 12.53 75 0.92 0.00 0 0.00 7 0 12 2 80
0 76 0.00 0 0.00 12.76 135 1.68 0.00 0 0.00 13 0 14 2 71
0 76 0.00 0 0.00 12.67 88 1.09 0.00 0 0.00 7 0 19 2 73
0 76 0.00 0 0.00 12.42 24 0.29 0.00 0 0.00 2 0 7 0 91
0 76 0.00 0 0.00 12.82 104 1.30 0.00 0 0.00 17 0 13 3 67
0 76 0.00 0 0.00 12.96 72 0.91 0.00 0 0.00 9 0 13 4 74
You can see that ad0 log traffic is bursty because syslogd (FreeBSD)
buffers the log lines and then dumps a chunk to disk, rather than writing
one log line at a time.
Len
