RE: IDE0 /dev/hda performance hit in 2217 on my HW - more info - maybe extended partitions

LA Walsh
2000-11-14T00:19:17Z

Some further information in response to a private email, I did hdparm -ti
under both
2216 and 2217 -- they are identical -- this may be something weird
w/extended
partitions...

/dev/hda:
multcount = 0 (off)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 3278/240/63, sectors = 49577472, start = 0

Model=IBM-DARA-225000, FwRev=SHAOA50A, SerialNo=SQASQ023976
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=3(DualPortCache), BuffSize=418kB, MaxMultSect=16, MultSect=off
DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2
CurCHS=17475/15/63, CurSects=16513875, LBA=yes, LBAsects=49577472
tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2
IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4
UDMA modes: mode0 mode1 *mode2 mode3 mode4
Drive Supports : ATA/ATAPI-4 T13 1153D revision 17 : ATA-1 ATA-2 ATA-3
ATA-4
---
Speed comparisons, 2216:
Timing buffered disk reads: 64 MB in 4.61 seconds = 13.88 MB/sec
Timing buffered disk reads: 64 MB in 4.65 seconds = 13.76 MB/sec
Timing buffered disk reads: 64 MB in 4.69 seconds = 13.65 MB/sec
2217:
Timing buffered disk reads: 64 MB in 4.59 seconds = 13.94 MB/sec
Timing buffered disk reads: 64 MB in 4.63 seconds = 13.82 MB/sec
Timing buffered disk reads: 64 MB in 4.56 seconds = 14.04 MB/sec

-------------

After rebooting several times, I can get equally bad performance on both.
:-(

Here's the key. I read from /dev/hda, hda1, {hda4, hda5, hda6, hda7} hda3.

The performance in reading from a, a1 and a3 is near or above 10M/s -- but
in the "Extended" partition, rates from 4-7 are all under 3M/s. So what's
the
deal? Why do extended partitions drop performance? Here's the log. Did
dd's if=device of=/dev/null, bs=128k count=1k. Timings are interwoven with
vmstat
output:
procs memory swap io system
cpu
r b w swpd free buff cache si so bi bo in cs us sy
id
1 0 0 1928 3188 432352 10976 1 3 3111 3 183 424 3 6
91
0 0 0 1928 3448 432352 10984 0 0 1 0 125 352 1 1
98
0 0 0 1928 3356 432352 11016 0 0 1 3 107 180 0 0
99
/dev/hda
1 0 0 1928 2068 433716 10984 0 0 12597 3 302 598 0 11
89
1 0 0 1928 2196 433600 10972 0 0 6810 0 208 388 0 6
94
0 1 0 1928 2132 433668 10968 0 0 8806 0 239 454 0 12
88
0 1 0 1928 2132 433668 10968 0 0 5914 0 193 357 0 4
96
2 0 0 1928 2100 430184 10484 0 0 12365 0 295 558 0 12
88
1024+0 records in
1024+0 records out
0.01user 2.31system 0:27.43elapsed 8%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda1
0 2 0 2572 2120 426948 10268 0 129 11805 33 292 544 0 14
86
0 1 0 2572 2940 422320 10268 0 0 10972 0 275 511 0 11
89
1 0 0 2572 2660 419024 10268 0 0 10266 2 264 485 0 9
91
0 1 0 2572 2052 418192 10268 0 0 11789 0 285 554 0 13
87
2 0 0 2572 2176 418044 10296 0 0 13045 0 307 608 0 17
83
1024+0 records in
1024+0 records out
0.01user 2.83system 0:22.71elapsed 12%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda3
1 0 0 2572 2048 418168 10296 0 0 14220 0 324 655 0 11
89
0 1 0 2572 2180 418040 10296 0 0 7027 3 213 398 0 7
93
0 1 0 2700 2116 418104 10424 0 26 8858 7 240 460 0 10
90
1 0 0 2956 2112 418464 10288 0 51 9651 13 253 488 0 17
83
1024+0 records in
1024+0 records out
0.03user 2.65system 0:24.70elapsed 10%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda4
2 1 0 2952 2736 417752 10424 26 0 13216 0 310 577 0 14
86
1 0 0 2952 2192 419716 10544 26 0 2159 0 237 428 0 9
91
1 0 0 2952 2808 419488 10484 0 0 2304 2 247 456 0 9
91
1 0 0 2948 3092 420260 10476 0 0 2406 1 252 461 0 9
91
procs memory swap io system
cpu
r b w swpd free buff cache si so bi bo in cs us sy
id
1 0 0 2948 2304 421540 10476 0 0 2355 0 249 459 0 7
93
2 0 0 2948 2588 421604 10476 0 0 2496 0 257 480 0 9
91
1024+0 records in
1024+0 records out
0.01user 2.12system 0:28.64elapsed 7%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda5
1 0 0 2948 2340 423172 10476 0 0 2394 1 251 471 0 8
92
1 0 0 3460 2596 425420 9988 0 102 2752 28 282 512 0 12
88
1 0 0 3460 2868 427536 9988 0 0 3162 0 299 559 0 12
88
1 0 0 3460 3088 428432 9988 0 0 3021 0 290 550 0 10
90
2 0 0 3460 2192 430288 9988 0 0 3059 0 293 550 0 12
88
1024+0 records in
1024+0 records out
0.02user 2.27system 0:21.96elapsed 10%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda6
0 1 0 3460 2192 430560 9988 0 0 2410 3 257 485 0 9
91
1 0 0 3460 2180 431232 9988 0 0 3085 0 295 560 0 11
89
1 0 0 3460 3068 430812 9988 0 0 2573 1 262 498 0 7
93
1 0 0 3460 2068 432412 9988 0 0 3162 0 299 577 0 10
90
1024+0 records in
1024+0 records out
0.00user 2.01system 0:24.25elapsed 8%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
/dev/hda7
2 0 0 3460 2176 432488 9988 0 0 2292 1 246 464 0 9
91
1 0 0 3460 2196 432584 9988 0 0 2637 3 268 502 0 11
89
1 0 0 3460 3100 431980 9992 0 0 2662 1 268 508 0 10
90
0 1 0 3460 2192 433284 9992 0 0 2380 0 249 462 0 8
92
1 0 0 3460 2184 433572 9992 11 0 1334 0 185 324 0 6
94
2 0 0 3452 2176 434184 10044 2 0 2970 0 287 543 0 12
88
1024+0 records in
1024+0 records out
0.00user 2.32system 0:27.18elapsed 8%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (104major+76minor)pagefaults 0swaps
1 0 0 3452 3028 433744 10044 0 0 794 0 151 256 0 3
97
0 0 0 3452 3156 433616 10044 0 0 0 0 102 143 0 0
100
0 0 0 3452 3132 433616 10044 0 0 0 0 114 241 1 0
99
0 0 0 3452 3132 433616 10044 0 0 0 0 114 182 0 0
100