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Czołem,
tworząc maszynki wirtualne mamy zazwyczaj do wyboru zarówno format dysku, jak i opcje cache.
Do testów uzyłem maszyny z dyskiem twardym 50 G, 4G ram, dysk w formacie RAW:
1) RAW -> cache=none:
root@test:~ # diskinfo -c /dev/vtbd0 /dev/vtbd0 512 # sectorsize 53687091200 # mediasize in bytes (50G) 104857600 # mediasize in sectors 0 # stripesize 0 # stripeoffset 104025 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. # Disk ident. I/O command overhead: time to read 10MB block 0.085699 sec = 0.004 msec/sector time to read 20480 sectors 12.162316 sec = 0.594 msec/sector calculated command overhead = 0.590 msec/sector root@test:~ # diskinfo -t /dev/vtbd0 /dev/vtbd0 512 # sectorsize 53687091200 # mediasize in bytes (50G) 104857600 # mediasize in sectors 0 # stripesize 0 # stripeoffset 104025 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. # Disk ident. Seek times: Full stroke: 250 iter in 0.090048 sec = 0.360 msec Half stroke: 250 iter in 0.103293 sec = 0.413 msec Quarter stroke: 500 iter in 0.970505 sec = 1.941 msec Short forward: 400 iter in 0.549123 sec = 1.373 msec Short backward: 400 iter in 1.195440 sec = 2.989 msec Seq outer: 2048 iter in 0.879379 sec = 0.429 msec Seq inner: 2048 iter in 0.876517 sec = 0.428 msec Transfer rates: outside: 102400 kbytes in 0.794245 sec = 128927 kbytes/sec middle: 102400 kbytes in 0.502954 sec = 203597 kbytes/sec inside: 102400 kbytes in 0.262135 sec = 390638 kbytes/sec
2) RAW -> cache=writethrough:
root@test:~ # diskinfo -c /dev/vtbd0 /dev/vtbd0 512 # sectorsize 53687091200 # mediasize in bytes (50G) 104857600 # mediasize in sectors 0 # stripesize 0 # stripeoffset 104025 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. # Disk ident. I/O command overhead: time to read 10MB block 0.059608 sec = 0.003 msec/sector time to read 20480 sectors 5.189635 sec = 0.253 msec/sector calculated command overhead = 0.250 msec/sector root@test:~ # diskinfo -t /dev/vtbd0 /dev/vtbd0 512 # sectorsize 53687091200 # mediasize in bytes (50G) 104857600 # mediasize in sectors 0 # stripesize 0 # stripeoffset 104025 # Cylinders according to firmware. 16 # Heads according to firmware. 63 # Sectors according to firmware. # Disk ident. Seek times: Full stroke: 250 iter in 0.117120 sec = 0.468 msec Half stroke: 250 iter in 0.038454 sec = 0.154 msec Quarter stroke: 500 iter in 0.270352 sec = 0.541 msec Short forward: 400 iter in 0.411616 sec = 1.029 msec Short backward: 400 iter in 0.737363 sec = 1.843 msec Seq outer: 2048 iter in 0.479056 sec = 0.234 msec Seq inner: 2048 iter in 0.460345 sec = 0.225 msec Transfer rates: outside: 102400 kbytes in 0.252984 sec = 404769 kbytes/sec middle: 102400 kbytes in 0.295906 sec = 346056 kbytes/sec inside: 102400 kbytes in 0.194296 sec = 527031 kbytes/sec
Testowałem jeszcze writeback, ale wypada troszkę gorzej niż writethrough, więc nie wklejałem.
Czy ktoś z Was, robił może podobne testy, ale na QCOW2? Z tego co wiem, jest mniej wydajny, aniżeli RAW ale wg pewnego poradnika, QCOW2 z opcją
-o preallocation=metadata
i wyłączonym cachem, bije na łeb RAW z opcją cache=writethrough
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[offtop]
Skąd można pobrać narzędzie [tt][b]diskinfo[/b][/tt]? W repo tego nie widzę.
[/offtop]
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Testowałem na FreeBSD, tam jest w systemie, nie wiem jak w Debianie
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Time (s) | Query |
---|---|
0.00010 | SET CHARSET latin2 |
0.00007 | SET NAMES latin2 |
0.00061 | SELECT u.*, g.*, o.logged FROM punbb_users AS u INNER JOIN punbb_groups AS g ON u.group_id=g.g_id LEFT JOIN punbb_online AS o ON o.ident='18.117.145.67' WHERE u.id=1 |
0.00153 | REPLACE INTO punbb_online (user_id, ident, logged) VALUES(1, '18.117.145.67', 1733053751) |
0.00024 | SELECT * FROM punbb_online WHERE logged<1733053451 |
0.00049 | SELECT topic_id FROM punbb_posts WHERE id=263423 |
0.00027 | SELECT id FROM punbb_posts WHERE topic_id=25619 ORDER BY posted |
0.00080 | SELECT t.subject, t.closed, t.num_replies, t.sticky, f.id AS forum_id, f.forum_name, f.moderators, fp.post_replies, 0 FROM punbb_topics AS t INNER JOIN punbb_forums AS f ON f.id=t.forum_id LEFT JOIN punbb_forum_perms AS fp ON (fp.forum_id=f.id AND fp.group_id=3) WHERE (fp.read_forum IS NULL OR fp.read_forum=1) AND t.id=25619 AND t.moved_to IS NULL |
0.00030 | SELECT search_for, replace_with FROM punbb_censoring |
0.00048 | SELECT u.email, u.title, u.url, u.location, u.use_avatar, u.signature, u.email_setting, u.num_posts, u.registered, u.admin_note, p.id, p.poster AS username, p.poster_id, p.poster_ip, p.poster_email, p.message, p.hide_smilies, p.posted, p.edited, p.edited_by, g.g_id, g.g_user_title, o.user_id AS is_online FROM punbb_posts AS p INNER JOIN punbb_users AS u ON u.id=p.poster_id INNER JOIN punbb_groups AS g ON g.g_id=u.group_id LEFT JOIN punbb_online AS o ON (o.user_id=u.id AND o.user_id!=1 AND o.idle=0) WHERE p.topic_id=25619 ORDER BY p.id LIMIT 0,25 |
0.00104 | UPDATE punbb_topics SET num_views=num_views+1 WHERE id=25619 |
Total query time: 0.00593 s |