18.18 ¸ß¿ÉÓÃÐÔ´æ´¢ (HAST)

Contributed by Daniel Gerzo. With inputs from Freddie Cash¡¢ Pawel Jakub Dawidek¡¢ Michael W. Lucas ºÍ Viktor Petersson.

18.18.1 ¸ÅÊö

¡¡¡¡¸ß¿ÉÓÃÐÔÊǵ£¸º¹Ø¼üÒµÎñµÄÓ¦ÓõÄÒ»ÏîÖ÷ÒªÐèÇó£¬ ¶ø¸ß¿ÉÓô洢ÔòÊÇÕâÀà»·¾³ÖеÄÒ»Ïî¹Ø¼ü×é¼þ¡£ ¸ß¿ÉÓô洢 Highly Available STorage£¬ »ò HAST£¬ ÊÇÓÉ Pawel Jakub Dawidek ¿ª·¢µÄÒ»ÖÖÓÃÓÚÌṩÔÚÁ½Ì¨ÎïÀíÉϸôÀëµÄϵͳ֮¼äÒÔ͸Ã÷µÄ·½Ê½£¬ ͨ¹ý TCP/IP ÍøÂç´«ÊäÊý¾ÝµÄ¸ß¿ÉÓÃÐÔ¿ò¼Ü¡£ HAST ¿ÉÒÔ¿´×÷ͨ¹ýÍøÂç½øÐÐµÄ RAID1 (¾µÏñ)£¬ ÀàËÆÓÚ GNU/Linux® ƽ̨É쵀 DRBD® ´æ´¢ÏµÍ³¡£ ÅäºÏ FreeBSD ÌṩµÄÆäËû¸ß¿ÉÓÃÐÔ»ù´¡ÉèÊ©£¬ Èç CARP£¬ HAST ¿ÉÒÔÓÃÀ´¹¹½¨¿ÉÒÔ¿¹ÓùÓ²¼þ¹ÊÕϵĸ߿ÉÓô洢¼¯Èº¡£

¡¡¡¡¶ÁÍêÕâ½Ú£¬ Äú½«Á˽⣺

¡¡¡¡ÔÚÔĶÁÕâ½Ú֮ǰ£¬ ÄúÓ¦£º

¡¡¡¡HAST ÏîÄ¿ÊÇÓÉ FreeBSD »ù½ð»á×ÊÖúÍê³ÉµÄ£¬ ²¢µÃµ½ÁËÀ´×Ô OMCnet Internet Service GmbH ºÍ TransIP BV µÄÖ§³Ö¡£

18.18.2 HAST µÄ¹¦ÄÜ

¡¡¡¡HAST ϵͳÌṩµÄ¹¦ÄÜÖ÷Òª°üÀ¨£º

18.18.3 HAST µÄÔËÐлúÖÆ

¡¡¡¡ÓÉÓÚ HAST ±¾ÖÊÉÏÊÇÔÚ¶à¸ö»úÆ÷¼äͬ²½µØ½øÐп鼶¸´ÖÆ£¬ Òò´ËËüÐèÒªÖÁÉÙÁ½¸ö½Úµã (ÎïÀíµÄ»úÆ÷) ©¤©¤ ÆäÒ»×÷Ϊ Ö÷ (Ò²³Æ×÷ master) ½Úµã£¬ ÁíÒ»¸ö×÷Ϊ ´Ó (slave) ½Úµã¡£ ÕâÁ½Ì¨»úÆ÷»á¹²Í¬¹¹³ÉÒ»¸ö¼¯Èº¡£

×¢Òâ: Ŀǰ HAST Ö»ÄÜʹÓÃ×î¶àÁ½¸ö¼¯Èº½Úµã¡£

¡¡¡¡ÓÉÓÚ HAST ÊÇÅäÖóÉÒÔÖ÷´Ó½ÚµãµÄ·½Ê½ÔËÐУ¬ ÔÚÈκÎʱ¿Ì¶¼Ö»ÄÜÓÐΨһµÄÒ»¸ö½ÚµãÊÇÖ÷½Úµã¡£ Ö÷ ½Úµã£¬ Ò²³Æ×÷ »îÔ¾ ½Úµã£¬ ¸ºÔð´¦ÀíÓÉ HAST ¹ÜÀíµÄÉ豸µÄÈ«²¿ I/O ÇëÇó¡£ ¶ø ´Ó ½ÚµãÔò»á×Ô¶¯´Ó Ö÷ ½Úµãͬ²½Êý¾ÝµÄ±ä¸ü²Ù×÷¡£

¡¡¡¡ÔÚ HAST ϵͳÖеÄÎïÀíÉ豸°üÀ¨£º

¡¡¡¡HAST ÔÚ¿éµÄ¼¶±ðÉÏͬ²½ÔËÐУ¬ ÕâʹÆä¶ÔÎļþϵͳºÍÓ¦ÓóÌÐò͸Ã÷¡£ HAST ÔÚ /dev/hast/ Ŀ¼ÖÐÌṩ±ê×¼µÄ GEOM É豸¹©ÆäËû¹¤¾ß»òÓ¦ÓóÌÐòʹÓ㬠Òò´Ë£¬ ÔÚʹÓÃÉÏ£¬ ¶ÔÓ¦ÓóÌÐò»òÎļþϵͳ¶øÑÔ£¬ HAST ÌṩµÄÉ豸ÓëÆÕͨµÄÂãÅÌ»ò·ÖÇøµÈûÓÐÈκÎÇø±ð¡£

¡¡¡¡·¢µ½±¾µØ´ÅÅ̵Äÿ´Îд¡¢ ɾ³ý»ò»º´æË¢Ð´²Ù×÷£¬ ¶¼»áͬʱͨ¹ý TCP/IP ·¢µ½Ô¶³Ì´ÅÅÌÉÏ¡£ ¶Á²Ù×÷ÊÇÓɱ¾µØ´ÅÅÌÍê³É£¬ ³ý·Ç±¾µØ´ÅÅÌÉϵÄÊý¾Ý²»ÊÇ×îÐµģ¬ »ò·¢ÉúÁË I/O ´íÎó¡£ ÔÚÕâÖÖÇé¿öÏ£¬ ¶Á²Ù×÷»áÔÚ´Ó½ÚµãÉÏÍê³É¡£

18.18.3.1 ͬ²½¼°¸´ÖÆÄ£Ê½

¡¡¡¡HAST Ï£ÍûÌṩ¿ìËٵĹÊÕϻָ´ÄÜÁ¦¡£ »ùÓÚÕâÒ»¿¼Á¿£¬ ¼õÉÙÔÚij¸ö½ÚµãÍ£»úºóÐèÒªµÄͬ²½Ê±¼ä¾ÍÊ®·ÖÖØÒª¡£ ΪÁËÌṩ¿ìËÙµÄͬ²½ÄÜÁ¦£¬ HAST »áά»¤Ò»·Ý±£´æÔÚ´ÅÅÌÉϵÄÔàÇø¶ÎλӳÉä±í (bitmap of dirty extents)£¬ ÔÚÆÕͨµÄͬ²½Ä£Ê½ÖУ¬ Ëüֻͬ²½ÕâЩ²¿·ÖµÄÊý¾Ý (³õʼµÄͬ²½³ýÍâ)¡£

¡¡¡¡´¦Àíͬ²½ÓжàÖÖ²»Í¬µÄ·½Ê½£¬ HAST ¼Æ»®ÊµÏÖÒÔϼ¸ÖÖͬ²½·½Ê½£º

  • memsync£º µ±±¾µØµÄд²Ù×÷ÒѾ­Íê³É£¬ ²¢ÇÒÔ¶³Ì½Úµã»ã±¨ÒѾ­ÊÕµ½Êý¾Ýʱ£¬ ±ãÈÏΪÊý¾ÝµÄд²Ù×÷ÒѾ­Íê³É£¬ ¶ø²»ÊǵȴýÔ¶³Ì½ÚµãÍê³ÉÊý¾ÝµÄд²Ù×÷¡£ Ô¶³Ì½ÚµãÔÚ·¢³ö»ØÓ¦Ö®ºó£¬ »áÁ¢¼´¿ªÊ¼Ö´ÐÐд²Ù×÷¡£ ÕâÖÖģʽµÄÄ¿±êÊǼõÉÙÏìӦʱ¼ä£¬ µ«ÔÚͬʱÈÔÈ»±£³ÖºÜºÃµÄ¿É¿¿ÐÔ¡£ Ŀǰ memsync ¸´ÖÆÄ£Ê½ÉÐδʵÏÖ¡£

  • fullsync£º Ö»ÓÐÔÚ±¾µØÐ´²Ù×÷Íê³É£¬ ²¢ÇÒÔ¶³ÌµÄд²Ù×÷Ò²ÒѾ­Íê³ÉµÄÇé¿öÏ£¬ ²ÅÈÏΪÊý¾ÝµÄд²Ù×÷ÒѾ­Íê³É¡£ ÕâÖÖģʽÊÇ×î±£ÏÕ£¬ ͬʱҲÊÇ×îÂýµÄÒ»ÖÖ¸´ÖÆÄ£Ê½¡£ ÕâÊÇĿǰϵͳԤÉèµÄ¸´ÖÆÄ£Ê½¡£

  • async£º ÔÚ±¾µØÐ´²Ù×÷Íê³Éʱ£¬ ¼´ÈÏΪÊý¾ÝÒѾ­Ð´Íê¡£ ÕâÊÇ×î¿ì£¬ ͬʱҲÊÇ·çÏÕ×î´óµÄ¸´ÖÆÄ£Ê½£¬ Ò»°ã¶øÑÔÖ»ÓÐÔÚÁíÒ»½ÚµãµÄÑӳٽϴóʱ²ÅÓ¦¿¼ÂÇʹÓᣠĿǰ async ¸´ÖÆÄ£Ê½ÉÐδʵÏÖ¡£

¾¯¸æ: Ŀǰ£¬ Ö»Ö§³Ö fullsync ¸´ÖÆÄ£Ê½¡£

18.18.4 HAST µÄÅäÖÃ

¡¡¡¡HAST ÐèÒª GEOM_GATE Ö§³Ö²ÅÄÜÕý³£¹¤×÷¡£ ϵͳ×Ô´øµÄÔ¤Éè GENERIC ÄÚºË ²¢²» °üº¬ GEOM_GATE£¬ µ«Ä¬È쵀 FreeBSD °²×°°üº¬ÁË geom_gate.ko ÄÚºËÄ£¿é¡£ Èç¹û¶Ôϵͳ½øÐÐÁ˲üô£¬ ÔòӦȷÈÏÕâ¸öÄ£¿éÊÇ·ñ¿ÉÓᣠ´ËÍ⣬ GEOM_GATE Ò²¿ÉÒÔ¾²Ì¬Áª±à½øÄںˣ¬ ·½·¨ÊÇÔÚÄں˵ıàÒëÅäÖÃÖÐÌí¼ÓÏÂÃæµÄÉèÖãº

options	GEOM_GATE

¡¡¡¡´Ó²Ù×÷ϵͳµÄ½Ç¶È£¬ HAST ¿ò¼Ü°üº¬ÁËÏÂÃæÕâЩ²¿¼þ£º

¡¡¡¡ÏÂÃæµÄÀý×Ó½«½éÉÜʹÓà HAST ÔÚÁ½¸ö½ÚµãÖ®¼äÒÔ Ö÷-´Ó ģʽ¸´ÖÆÊý¾ÝµÄ·½·¨¡£ Á½¸ö½ÚµãµÄÃû×Ö·Ö±ðÊÇ hasta Æä IP£¬ µØÖ·Îª 172.16.0.1£¬ ÒÔ¼° hastb£¬ Æä IP µØÖ·Îª 172.16.0.2¡£ ÕâÁ½Ì¨»úÆ÷¶¼Ê¹ÓóߴçÏàͬµÄ´ÅÅÌ /dev/ad6 À´×¨ÓÃÓÚ HAST µÄÔËÐС£ HAST ´æ´¢³Ø (ÓÐʱҲ³ÆÎª×ÊÔ´£¬ ÀýÈçλÓÚ /dev/hast/ µÄÉ豸Îļþ) ½«ÃüÃûΪ test¡£

¡¡¡¡HAST µÄÅäÖÃÎļþÊÇ /etc/hast.conf¡£ ÔÚÁ½¸ö½ÚµãÉÏ£¬ Õâ¸öÎļþµÄÄÚÈÝÓ¦¸ÃÊÇÍêȫһÑùµÄ¡£ ×î¼òÅäÖÃÈçÏ£º

resource test {
	on hasta {
		local /dev/ad6
		remote 172.16.0.2
	}
	on hastb {
		local /dev/ad6
		remote 172.16.0.1
	}
}

¡¡¡¡Èç¹ûÐèÒª¸ü¸ß¼¶µÄÅäÖ㬠Çë²ÎÔÄÁª»úÊÖ²á hast.conf(5)¡£

Ìáʾ: ÔÚ remote Óï¾äÖÐÒ²¿ÉÒÔʹÓÃÖ÷»úÃû¡£ ÕâÖÖÇé¿öÏÂÐèҪȷ±£ÕâЩÖ÷»úÃûÊÇ¿ÉÒÔ½âÎöµÄ£¬ ÀýÈçÔÚ /etc/hosts ÎļþÖУ¬ »òÔÚ±¾µØ DNS ÖнøÐÐÁ˶¨Òå¡£

¡¡¡¡ÏÖÔÚÔÚÁ½¸ö½ÚµãÉ϶¼ÓÐͬÑùµÄÅäÖÃÁË£¬ ½ÓÏÂÀ´ÎÒÃÇÐèÒª´´½¨ HAST ´æ´¢³Ø¡£ ÔÚÁ½¸ö½ÚµãÉÏ·Ö±ðÔËÐÐÏÂÃæµÄÃüÁîÀ´³õʼ»¯±¾µØ´ËÅ£¬ ²¢Æô¶¯ hastd(8) ·þÎñ£º

# hastctl create test
# /etc/rc.d/hastd onestart

×¢Òâ: ûÓÐ °ì·¨Ê¹ÓÃÒѾ­°üº¬ÎļþϵͳµÄ GEOM É豸À´´´½¨´æ´¢³Ø (»»ÑÔÖ®£¬ ÒѾ­´æÔÚµÄÎļþϵͳÎÞ·¨×ª»»Îª HAST ¹ÜÀíµÄ´æ´¢³Ø)£¬ ÕâÊÇÒòΪ´´½¨´æ´¢³ØµÄ¹ý³ÌÐèÒª±£´æÒ»Ð©ÔªÊý¾Ý£¬ ¶øÒѾ­Ð´ÈëÎļþϵͳµÄÉ豸²»ÔÙÄÜÌṩ±£´æÕâЩԪÊý¾ÝËùÐèµÄ¿Õ¼ä¡£

¡¡¡¡HAST ²¢²»¸ºÔðÑ¡Ôñ½ÚµãµÄ½ÇÉ« (Ö÷ »ò ´Ó)¡£ ½ÚµãµÄ½ÇÉ«ÊÇÓɹÜÀíÔ±ÊÖ¹¤£¬ »òÓÉÀàËÆ Heartbeat ÕâÑùµÄÈí¼þͨ¹ý hastctl(8) À´Íê³ÉÅäÖõġ£ ÔÚÏ£Íû³ÉΪÖ÷½ÚµãµÄϵͳ (hasta) ÉÏÔËÐÐÏÂÃæµÄÃüÁîÁîÆä³ÉΪÖ÷½Úµã£º

# hastctl role primary test

¡¡¡¡ÀàËÆµØ£¬ ÓÃÏÂÃæµÄÃüÁîÀ´Ö¸Ã÷´Ó½Úµã (hastb)£º

# hastctl role secondary test

СÐÄ: ÓпÉÄÜ»á³öÏÖÁ½¸ö½ÚµãÖ®¼äÎÞ·¨Õý³£Í¨Ñ¶£¬ µ«ÓÖ¶¼ÅäÖÃΪÖ÷½ÚµãÕâÑùµÄÇé¿ö£» ÕâÖÖ³Æ×÷ ÄÔ·ÖÁÑ µÄ״̬ÊÇÊ®·ÖΣÏյġ£ ÔÚ µÚ 18.18.5.2 ½Ú ÖнéÉÜÁËÈçºÎ´ÓÕâÖÖ״̬Öлָ´µÄ·½·¨¡£

¡¡¡¡½ÓÏÂÀ´£¬ ¿ÉÒÔÔÚÁ½¸ö½ÚµãÉÏ·Ö±ðÓà hastctl(8) ¹¤¾ßÀ´ÑéÖ¤½ÚµãÉí·ÝÊÇ·ñÕýÈ·£º

# hastctl status test

¡¡¡¡ÕâÆäÖбȽÏÖØÒªµÄÊÇ status(״̬) ÕâÐУ¬ ÔÚÁ½¸ö½ÚµãÉÏ£¬ ÆäÊä³ö¾ùӦΪ complete(ÍêºÃ)¡£ Èç¹ûϵͳ¸ø³öµÄÊä³öÊÇ degraded (½µ¼¶)£¬ Ôò±íʾ³öÏÖÁËÎÊÌâ¡£ Õý³£Çé¿öÏ£¬ ½Úµã¼äµÄͬ²½ÒѾ­¿ªÊ¼¡£ µ± hastctl status ÃüÁ¸æµÄ dirty Êý¾Ý¿éÊýÁ¿Îª 0 ×Ö½Úʱ£¬ ±íʾÁ½¸ö½ÚµãµÄÊý¾ÝÒѾ­Íêȫͬ²½¡£

¡¡¡¡×îºóÒ»²½ÊÇÔÚ GEOM É豸 /dev/hast/test ÉÏ´´½¨Îļþϵͳ¡£ ÕâÏ×÷±ØÐëÔÚ Ö÷ ½ÚµãÉϽøÐÐ (ÒòΪ /dev/hast/test Ö»ÔÚ Ö÷ ½ÚµãÉϳöÏÖ)£¬ ËæÓ²Å̳ߴçµÄ²»Í¬£¬ Õâ¿ÉÄÜÐèÒª»¨·ÑÊý·ÖÖÓµÄʱ¼ä£º

# newfs -U /dev/hast/test
# mkdir /hast/test
# mount /dev/hast/test /hast/test

¡¡¡¡Ò»µ©Íê³ÉÁË HAST ¿ò¼ÜµÄÅäÖ㬠×îºóÒ»²½¾ÍÊÇÈ·±£ HAST ÔÚϵͳÒýµ¼¹ý³ÌÖлá×Ô¶¯Æô¶¯ÁË¡£ ΪÁË´ïµ½Õâ¸öÄ¿µÄ£¬ Ó¦ÔÚ /etc/rc.conf ÎļþÖÐÌí¼ÓÕâÐÐÅäÖãº

hastd_enable="YES"

18.18.4.1 ¹ÊÕÏ×ªÒÆÅäÖÃ

¡¡¡¡Õâ¸öÀý×ÓµÄÄ¿µÄÔÚÓÚ½¨Á¢Ò»Ì×½¡×³µÄ´æ´¢ÏµÍ³£¬ ÁîÆäÄܹ»µÖÓùÔÚÈκÎÒ»¸ö½ÚµãÉÏ·¢ÉúµÄ¹ÊÕÏ¡£ ÕâÆäÖеĹؼüÈÎÎñÊǶԼ¯ÈºÖÐµÄ Ö÷ ½Úµã·¢Éú¹ÊÕϵÄÇéÐνøÐм°Ê±µÄ²¹¾È´¦Àí¡£ µ±·¢ÉúÕâÖÖÇé¿öʱ£¬ ´Ó ½Úµã¿ÉÒÔÎÞ·ìµØ½ÓÊÖÖ÷½ÚµãµÄ¹¤×÷£¬ ¶ÔÎļþϵͳ½øÐмì²é²¢¹Ò½Ó£¬ ´Ó¶ø¼ÌÐøÔËÐУ¬ ¶ø²»ËðʧÈκÎÊý¾Ý¡£

¡¡¡¡ÎªÁË´ï³ÉÕâÒ»ÈÎÎñ£¬ ÐèҪʹÓà FreeBSD ÌṩµÄÁíÒ»ÏÄÜ ©¤©¤ CARP ËùÌṩµÄ IP ²ã×Ô¶¯¹ÊÕÏ×ªÒÆÄÜÁ¦¡£ CARP Êǹ²ÓõØÖ·ÈßÓàЭÒé Common Address Redundancy Protocol µÄËõд£¬ ËüÔÊÐí¶à¸öÍ¬Íø¶ÎµÄÖ÷»ú¹²Ïíͬһ IP µØÖ·¡£ Çë¸ù¾Ý µÚ 31.13 ½Ú µÄ½éÉÜÔÚÁ½¸ö½ÚµãÉ϶¼ÅäÖà CARP¡£ Íê³ÉÕâЩÅäÖÃÖ®ºó£¬ Á½¸ö½Úµã¶¼»áÓÐ×Ô¼ºµÄ carp0 ÍøÂç½Ó¿Ú£¬ ¹²Óà IP µØÖ· 172.16.0.254¡£ ÏÔÈ»£¬ ¼¯ÈºÖÐµÄ HAST Ö÷½ÚµãÒ²±ØÐëÊÇ CARP Ö÷½Úµã¡£

¡¡¡¡Ç°ÃæÒ»½ÚÖд´½¨µÄ HAST ´æ´¢³ØÏÖÔÚ¿ÉÒÔÌṩ¸øÍøÂçÉÏµÄÆäËûÖ÷»úʹÓÃÁË¡£ ÆäÉϵÄÎļþϵͳ¿ÉÒÔͨ¹ý NFS¡¢ Samba µÈµÈ£¬ ÒÔ¹²Óà IP µØÖ· 172.16.0.254 À´·ÃÎÊ¡£ ÏÖÔÚÓàϵÄΨһÎÊÌâÊÇ×Ô¶¯»¯¶ÔÖ÷½Úµã¹ÊÕϵĴ¦Àí¡£

¡¡¡¡µ± CARP ÍøÂç½Ó¿ÚµÄÁ´Â·×´Ì¬·¢Éú±ä»¯Ê±£¬ FreeBSD ²Ù×÷ϵͳ»á²úÉúÒ»¸ö devd(8) ÏûÏ¢£¬ ÕâÑù¾Í¿ÉÒÔ¼àÊÓ CARP ÍøÂç½Ó¿ÚµÄ״̬ÁË¡£ CARP ½Ó¿ÚµÄ״̬±ä»¯±íʾ½Úµã·¢Éú¹ÊÕÏ£¬ »òÖØÐ»ص½ÁËÍøÂçÖС£ ÕâЩÇé¿öÏÂÐèÒªÔËÐÐÌØ¶¨µÄ½Å±¾À´Íê³É¶ÔÓ¦µÄ´¦Àí¡£

¡¡¡¡ÎªÁ˽ػñ CARP ÍøÂç½Ó¿ÚµÄ״̬±ä»¯£¬ ÐèÒªÔÚÁ½¸ö½ÚµãµÄ /etc/devd.conf ÎļþÖÐÌí¼ÓÈçϵÄÉèÖãº

notify 30 {
	match "system" "IFNET";
	match "subsystem" "carp0";
	match "type" "LINK_UP";
	action "/usr/local/sbin/carp-hast-switch master";
};

notify 30 {
	match "system" "IFNET";
	match "subsystem" "carp0";
	match "type" "LINK_DOWN";
	action "/usr/local/sbin/carp-hast-switch slave";
};

¡¡¡¡ÎªÊ¹±à¼­µÄÅäÖÃÉúЧ£¬ ÐèÒªÔÚÁ½¸ö½ÚµãÉÏÖ´ÐÐÏÂÃæµÄÃüÁ

# /etc/rc.d/devd restart

¡¡¡¡µ±ÍøÂç½Ó¿Ú carp0 µÄ״̬·¢Éú±ä»¯Ê±£¬ ϵͳ»á²úÉúÒ»¸ö֪ͨÏûÏ¢£¬ ÕâÔÊÐí devd(8) ×ÓϵͳÔËÐйÜÀíÔ±Ö¸¶¨µÄÈÎÒâ½Å±¾£¬ ÔÚÕâ¸öÀý×ÓÖÐÊÇ /usr/local/sbin/carp-hast-switch¡£ Õâ¸ö½Å±¾µÄ×÷ÓÃÊÇ×Ô¶¯»¯¹ÊÕÏ×ªÒÆ¡£ ¹ØÓÚÇ°Ãæ devd(8) ÅäÖõľßÌ庬Ò壬 Çë²ÎÔÄÁª»úÊÖ²á devd.conf(5)¡£

¡¡¡¡ÏÂÃæÊÇÒ»¸öÕâÖֽű¾µÄʾÀý£º

#!/bin/sh

# Original script by Freddie Cash <fjwcash@gmail.com>
# Modified by Michael W. Lucas <mwlucas@BlackHelicopters.org>
# and Viktor Petersson <vpetersson@wireload.net>

# The names of the HAST resources, as listed in /etc/hast.conf
resources="test"

# delay in mounting HAST resource after becoming master
# make your best guess
delay=3

# logging
log="local0.debug"
name="carp-hast"

# end of user configurable stuff

case "$1" in
	master)
		logger -p $log -t $name "Switching to primary provider for ${resources}."
		sleep ${delay}

		# Wait for any "hastd secondary" processes to stop
		for disk in ${resources}; do
			while $( pgrep -lf "hastd: ${disk} \(secondary\)" > /dev/null 2>&1 ); do
				sleep 1
			done

			# Switch role for each disk
			hastctl role primary ${disk}
			if [ $? -ne 0 ]; then
				logger -p $log -t $name "Unable to change role to primary for resource ${disk}."
				exit 1
			fi
		done

		# Wait for the /dev/hast/* devices to appear
		for disk in ${resources}; do
			for I in $( jot 60 ); do
				[ -c "/dev/hast/${disk}" ] && break
				sleep 0.5
			done

			if [ ! -c "/dev/hast/${disk}" ]; then
				logger -p $log -t $name "GEOM provider /dev/hast/${disk} did not appear."
				exit 1
			fi
		done

		logger -p $log -t $name "Role for HAST resources ${resources} switched to primary."


		logger -p $log -t $name "Mounting disks."
		for disk in ${resources}; do
			mkdir -p /hast/${disk}
			fsck -p -y -t ufs /dev/hast/${disk}
			mount /dev/hast/${disk} /hast/${disk}
		done

	;;

	slave)
		logger -p $log -t $name "Switching to secondary provider for ${resources}."

		# Switch roles for the HAST resources
		for disk in ${resources}; do
			if ! mount | grep -q "^/dev/hast/${disk} on "
			then
			else
				umount -f /hast/${disk}
			fi
			sleep $delay
			hastctl role secondary ${disk} 2>&1
			if [ $? -ne 0 ]; then
				logger -p $log -t $name "Unable to switch role to secondary for resource ${disk}."
				exit 1
			fi
			logger -p $log -t $name "Role switched to secondary for resource ${disk}."
		done
	;;
esac

¡¡¡¡¼ò¶øÑÔÖ®£¬ ÔÚ½Úµã³ÉÎªÍøÂçµÄ master / primary ½Úµãʱ£¬ ½Å±¾»á½øÐÐÏÂÃæµÄ²Ù×÷£º

  • ÔÚ±¾½ÚµãÉý¸ñΪ HAST ´æ´¢³ØµÄÖ÷½Úµã¡£

  • ¼ì²é HAST ´æ´¢³ØÉϵÄÎļþϵͳ¡£

  • ¹Ò½Ó´æ´¢³ØÖеÄÎļþϵͳµ½Êʵ±µÄλÖá£

¡¡¡¡µ±½Úµã³ÉΪ backup / secondary ½Úµãʱ£º

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