Existem diferentes formas de realizar o espelhamento de disco, via hardware com uma controladora SCSI ou software. Em ambos os casos existem vantagens e desvantagem antes de tomar qualquer decisão é preciso analisar qual seu cenário, pense no futuro quando for necessário mexer nessa estrutura.
Especificações que vamos usar para o exemplo:
c0t361CEB4725D71723d0s0 = disco principal, onde está instalado o sistema operacional
c0t3B7CA031337740CDd0s0 = disco secundário
Dica: A identificação dos disco do exemplo podem parecer um pouco diferentes, isso porque são volumes logicos em vez de discos físicos.
Primeiro localize os discos reconhecidos pelo sitema:
bash-3.2# ls /dev/rdsk/*s0
/dev/rdsk/c0t361CEB4725D71723d0s0 /dev/rdsk/c0t3B7CA031337740CDd0s0 /dev/rdsk/c1t6d0s0 /dev/rdsk/c2t0d0s0
Comando para realizar o espelhanto dos discos:
bash-3.2# zpool attach -f rpool c0t361CEB4725D71723d0s0 c0t3B7CA031337740CDd0s0
Em caso de erro no espelhamento do RAID, será necessário acertar os slices dos disco novo:
bash-3.2# zpool attach -f rpool c0t361CEB4725D71723d0s0 c0t3B7CA031337740CDd0s0
cannot attach c0t3B7CA031337740CDd0s0 to c0t361CEB4725D71723d0s0: device is too small
Verificar os slices do disco 1:
bash-3.2# prtvtoc /dev/rdsk/c0t361CEB4725D71723d0s0
* /dev/rdsk/c0t361CEB4725D71723d0s0 partition map
*
* Dimensions:
* 512 bytes/sector
* 139 sectors/track
* 128 tracks/cylinder
* 17792 sectors/cylinder
* 65535 cylinders
* 65533 accessible cylinders
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 0 1165963136 1165963135
2 5 00 0 1165963136 1165963135
Verificar os slices do disco 2:
bash-3.2# prtvtoc /dev/rdsk/c0t3B7CA031337740CDd0s0
* /dev/rdsk/c0t3B7CA031337740CDd0s0 partition map
*
* Dimensions:
* 512 bytes/sector
* 139 sectors/track
* 128 tracks/cylinder
* 17792 sectors/cylinder
* 65535 cylinders
* 65533 accessible cylinders
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 0 266880 266879
1 3 01 266880 266880 533759
2 5 01 0 1165963136 1165963135
6 4 00 533760 1165429376 1165963135
Veja que os slices estão diferentes, nesse caso é preciso ajustar isso antes de continuar o processo. O jeito mais fácil é criar um modelo baseado no HD principal e aplicá-lo no disco novo. Vamos criar um arquivo de modelo.
Criando um modelo basedo nos slices do disco principal:
bash-3.2# prtvtoc /dev/rdsk/c0t361CEB4725D71723d0s0 > /tmp/volume1.out
Aplicando o modelo no disco secundário:
bash-3.2# fmthard -s /tmp/volume1.out /dev/rdsk/c0t3B7CA031337740CDd0s0
fmthard: New volume table of contents now in place.
Verificar os slices do disco 1 novamente:
bash-3.2# prtvtoc /dev/rdsk/c0t361CEB4725D71723d0s0
* /dev/rdsk/c0t361CEB4725D71723d0s0 partition map
*
* Dimensions:
* 512 bytes/sector
* 139 sectors/track
* 128 tracks/cylinder
* 17792 sectors/cylinder
* 65535 cylinders
* 65533 accessible cylinders
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 0 1165963136 1165963135
2 5 00 0 1165963136 1165963135
Verificar os slices do disco 2 novamente:
bash-3.2# prtvtoc /dev/rdsk/c0t3B7CA031337740CDd0s0
* /dev/rdsk/c0t3B7CA031337740CDd0s0 partition map
*
* Dimensions:
* 512 bytes/sector
* 139 sectors/track
* 128 tracks/cylinder
* 17792 sectors/cylinder
* 65535 cylinders
* 65533 accessible cylinders
*
* Flags:
* 1: unmountable
* 10: read-only
*
* First Sector Last
* Partition Tag Flags Sector Count Sector Mount Directory
0 2 00 0 1165963136 1165963135
2 5 00 0 1165963136 1165963135
Agora é possivel continuar com attach nos discos:
bash-3.2# zpool attach -f rpool c0t361CEB4725D71723d0s0 c0t3B7CA031337740CDd0s0
Make sure to wait until resilver is done before rebooting.
Utilizando o comando zpool status acompanhe o processo de espelhamento.
Aviso: Quanto mais ocupado estiver o disco principal, mais lento e demorado será o processo de sincronismo. Além disso durante o processo de sincronismo a performance do servidor será afetada consideravelmente.
bash-3.2# zpool status
pool: rpool
state: ONLINE
status: One or more devices is currently being resilvered. The pool will
continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
scan: resilver in progress since Mon Apr 16 12:49:37 2012
3.46G scanned out of 6.54G at 111M/s, 0h0m to go
3.46G scanned out of 6.54G at 111M/s, 0h0m to go
3.46G resilvered, 52.95% done
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c0t361CEB4725D71723d0s0 ONLINE 0 0 0
c0t3B7CA031337740CDd0s0 ONLINE 0 0 0 (resilvering)
errors: No known data errors
Antes de fazer qualquer outra coisa aguarde o “resilvering” dos disco:
bash-3.2# zpool status
pool: rpool
state: ONLINE
status: One or more devices is currently being resilvered. The pool will
continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
scan: resilver in progress since Mon Apr 16 12:49:37 2012
6.50G scanned out of 6.54G at 63.4M/s, 0h0m to go
6.50G scanned out of 6.54G at 63.4M/s, 0h0m to go
6.50G resilvered, 99.36% done
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c0t361CEB4725D71723d0s0 ONLINE 0 0 0
c0t3B7CA031337740CDd0s0 ONLINE 0 0 0 (resilvering)
errors: No known data errors
Finalizado o resilvering e com isso o espelhamento do disco está completo:
bash-3.2# zpool status
pool: rpool
state: ONLINE
scan: resilvered 6.54G in 0h1m with 0 errors on Mon Apr 16 12:51:23 2012
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c0t361CEB4725D71723d0s0 ONLINE 0 0 0
c0t3B7CA031337740CDd0s0 ONLINE 0 0 0
errors: No known data errors
