Zmeny v GEOM / UFS - opozdeny zapis

[Miroslav Lachman]

Nesledujete nekdo podrobneji zmeny v kodu, nebo aspon chovani GEOM / UFS?
Zkousel jsem ted na novem stroji 9.1-RC3. Zkousel jsem ruzna nastaveni 
filesystemu / rozdeleni disku a testoval rychlost zapisu - rozbaleni 
ports.tgz

K memu prekvapeni dochazi k tomu, ze `tar xf ports.tgz` dobehne a jeste 
dalsi dve minuty probihaji zapisy na disk.

Vim, ze normalne takhle probihaji Soft Updates, ale tam byval myslim 
limit do 30 sekund a tak se to chova na 8.3. Rozbalim ports.tgz na 8.3 a 
zhruba do 20 sekund jeste probehnou nejake zapisy na disky a vic nic.

Na obou testovanych strojich je pouzity gmirror a UFS2 + SU - bez journalu.

Co vim, ze se rozhodne zmenilo, je vychozi velikost fragmentu ze 2k na 
4k a k tomu i velikost bloku z 16k na 32k. To by ale nemelo mit na tohle 
vliv.

Aby toho nebylo malo, tak na starem stroji s 8.3 a disky Samsung F1 1TB 
to rozbaleni ports.tgz trva mene nez minutu, cca 0:55.
Na novem Cisco UCS C200 se SATA III radicem a disky Seagate 
Constellation ES 1TB to trva dvojnasobek casu, cca 1:52

Oboje disky pouzivaji 512B, takze to ani neni problem se 4k sektory a 
nezarovnanymi partitions.
S tim jsem se potykal u jinych disku, kde pri nezarovnanych partitions a 
2k fragmentech namisto 4k fragmentu trva rozbaleni ports.tgz az 7 minut!

Jeste teda dalsi zmena 9.1 oproti 8.3 je ta, ze se pouziva AHCI a disky 
jsou jako ada0 a ada1. To uz jsem drive cetl, ze nekdo ma s touhle 
"novinkou" pomalejsi praci disku, nez se starsim rezimem.


Pro ilustraci jeste jak vypada ten opozdeny zapis na 9.1-RC3 z pohledu 
iostat (co zaznam, to 10 sekund)

root na ksdtm-s2 ~/# iostat -x -w 10 ada0 ada1
...
...
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 1193.6     0.0  7146.1 2545 1711.7  93
ada1       0.4 1196.5     1.6  7129.3 2596 1806.6  98
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 1180.9     0.0  7850.4 2851 1790.3  99
ada1       0.6 1168.5     2.4  7832.8 3026 1769.6  93
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 1210.1     0.0  7616.8 2124 1665.4  98
ada1       0.5 1210.2     2.0  7610.4 2298 1803.1  98
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 1076.2     0.0  5654.2 2167 1799.6  98
ada1       0.5 1072.1    10.4  5634.6 2382 1872.7  99
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 1338.6     0.0  7700.0  707 1985.2 100
ada1       0.0 1304.8     0.0  7536.0 1260 2264.7 100
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.9 1514.6     3.6  8796.3 2589 951.3  91
ada1       0.0 1563.7     0.0  9037.1 2651 1104.9  97
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.7 1186.7     2.8  5936.4 2605 1838.4  98
ada1       0.0 1191.0     0.0  5943.2 2624 1841.2  96  <-- konec 
rozbaleni tar
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 656.6     0.0  5893.4    0 1382.8  39
ada1       0.0 658.5     0.0  5910.2    0 1390.0  41
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 165.3     0.0   676.3    0 217.2  11
ada1       0.0 165.3     0.0   676.3    0 194.4  10
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 653.8     0.0  2870.1 1215 891.1  46
ada1       0.0 653.1     0.0  2867.3 1222 869.4  46
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 176.6     0.0  2148.2    0 2242.7  17
ada1       0.0 177.3     0.0  2151.0    0 2275.2  17
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 524.9     0.0  2106.2    0 346.9  22
ada1       0.0 524.9     0.0  2106.2    0 346.3  21
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 107.6     0.0  1073.0    0 126.0   8
ada1       0.0 107.6     0.0  1073.0    0 144.2   8
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 126.9     0.0   511.9    0 113.6   9
ada1       0.0 126.9     0.0   511.9    0 114.9   8
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0  35.8     0.0   142.9    0  69.3   2
ada1       0.0  35.8     0.0   142.9    0  67.1   2
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0  44.8     0.0   189.7    0 101.1   3
ada1       0.0  44.8     0.0   189.7    0 102.1   3
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0   0.2     0.0     0.4    0   0.2   0
ada1       0.0   0.2     0.0     0.4    0   0.3   0
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0 168.9     0.0   679.2    6 138.2  10
ada1       0.0 168.9     0.0   679.2    6 140.9  10
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0  17.7     0.0    70.1    0  49.5   2
ada1       0.0  17.7     0.0    70.1    0  50.6   2
                         extended device statistics
device     r/s   w/s    kr/s    kw/s qlen svc_t  %b
ada0       0.0   0.1     0.0     0.0    0   0.2   0
ada1       0.0   0.1     0.0     0.0    0   0.5   0

A jeste dodavam, ze nic jineho na ty disky nesaha, protoze system bezi z 
USB flashdisku a na tomhle mirroru nejsou zadna data, oddil byl pred 
rozbalenim ports.tgz cerstve naformatovan.

root na ksdtm-s2 ~/# dumpfs -m /dev/mirror/gm0s1e
# newfs command for /dev/mirror/gm0s1e (/dev/mirror/gm0s1e)
newfs -L test -O 2 -U -a 4 -b 32768 -d 32768 -e 4096 -f 4096 -g 16384 -h 
64 -m 8 -o time -s 20971520 /dev/mirror/gm0s1e

root na ksdtm-s2 ~/# tunefs -p /mnt/
tunefs: POSIX.1e ACLs: (-a)                                disabled
tunefs: NFSv4 ACLs: (-N)                                   disabled
tunefs: MAC multilabel: (-l)                               disabled
tunefs: soft updates: (-n)                                 enabled
tunefs: soft update journaling: (-j)                       disabled
tunefs: gjournal: (-J)                                     disabled
tunefs: trim: (-t)                                         disabled
tunefs: maximum blocks per file in a cylinder group: (-e)  4096
tunefs: average file size: (-f)                            16384
tunefs: average number of files in a directory: (-s)       64
tunefs: minimum percentage of free space: (-m)             8%
tunefs: optimization preference: (-o)                      time
tunefs: volume label: (-L)                                 test


Mirek