SSA FENCE

农哥，这啥意思啊。。。农哥是让我看ssa的分册吗？我看了，时间比较紧，上面的一堆东西，看得晕晕乎乎的

[ 本帖最后由 fengyan 于 2008-5-8 23:37 编辑 ]

exportvg后，在importvg，试试。

本来是想着这样干的，后来觉得此举要停双机，先这样干了一把：
1，        首先确定是由于cache_error操作引起的问题：
   ssaraid -l ssa0 -Iz –a state=wrong_cache；这个时候系统输出损坏的raid组信息，如下：
   81BA000D6E934CO 81BA000D6E934CO   wrong_cache 36.4GB Raid-5 array
2，        强制禁止fastwrite属性关闭，如下命令：
   ssaraid -l ssa0 -H -n 81BA000D6E934CO -a fastwrite=off -a force=yes -u
3，        重新创建丢失的磁盘
   ssaraid -l ssa0 -H -n 81BA000D6E934CO -a use=syestem -k hdisk2 -d
   此时输出hdisk2 available的信息，表明hdisk2磁盘恢复成功。hdisk3也做同样的操作
结果就发现主节点不行了，业务起不来了

前面做过什么不重要.
# varyonvg vgdata
0516-013 varyonvg: The volume group cannot be varied on because
        there are no good copies of the descriptor area.
这个提示一出现,那就是vgdata被别的节点varyonvg了

不完全同意楼上，我遇到的情况，A，B两机共享VGabc，因要求停双机后varyonvg vgabc，就出现这样的情况（报错信息都一样），确定的是两边vg被ha带varyoff了的。当时我就exportvg,在importvg后，就没这样的报错了。


回LZ，VG有问题，你双机怎么还在运行呀？你在主机手工varyon报错，但你说现在也不能停HA，那就是说你HA能带VG起来！！！

业务不能起来了！！！
在不知道操作的后果，你就进行操作，看来你是没看过，并没有深深理解过本论坛“《亲历惊心动魄48小时！》-要命的数据丢失”的帖子！


考虑好后果在下手，小心小心在小心。

[ 本帖最后由 飞刀刀 于 2008-5-9 00:39 编辑 ]

varyonvg和varyoffvg几下不会出太大的问题。
两边都varyoffvg后再说。都重起一下，然后一个个节点去挂载看看。

没说是共享vg，如何在两边都varyoffvg.

急不解决问题。
急的话，就应该找真的明白的人去解决，而不是自己瞎试。
你连ssa disk fence都不知道，做啥SSA的HACMP啊？

你有体会，但还没明白

SSA Disk Fencing
SSA disk fencing is a facility which is provided in the SSA subsystem to allow multiple hosts to control access to a common set of disks.

Using the fencing commands provided by the hardware it is possible to exclude individual hosts from accessing a particular disk. The access list for different disks are independent of one another.

Fencing is essentially a function provided by the hardware and manipulated using the hardware commands, but the device driver does have some involvement.

The SSA disk device driver supports fencing by allowing the FN_ISAL_FENCE command, which is defined in the SSA Adapter Technical Reference, to be issued to SSA logical disks using the SSADISK_ISALCMD ioctl operation.

In order to use fencing, the node_number attribute of the ssar router must be set to a different value on each host which is participating in fencing. Note that after setting node_number the host must be rebooted for the new value to take effect.

By default, the value of node_number is 0. This value has particular significance because it is not possible to exclude a host with node number 0 from access to the disk. Thus if a disk is moved from a machine which has been using fencing to a machine which is not involved in fencing, the new machine will be able to communicate with the disk.

If a host attempts to open a disk from which it has been denied access using the open subroutine, the return code will be -1 and the global variable errno will be set to the value ENOCONNECT. Likewise, if an application already has a SSA Logical disk open but since the open, it has been fenced out then calls to the read or write subroutine will fail, with errno set to ENOCONNECT.

The hardware fencing commands provide for a facility, to forcibly break through a fence. This command can be issued using the SSADISK_ISALCMD ioctl operation but it is necessary first to open the disk. A disk from which the host has been excluded can be opened by using the openx subroutine and specifying the SSADISK_FENCEMODE extension flag as described in SSA disk device driver device-dependant subroutines. While open in this mode no read or write operations will be permitted.

If a host has been excluded from access to a disk using fencing but that disk is also reserved to another host the reservation takes precedence. The return code from the open subroutine will be -1 and the global variable errno will be set to EBUSY. If the host attempts to break through the reservation by passing the ext parameter SSADISK_FORCED_OPEN to the openx subroutine, the reservation will be broken but the open will fail with errno set to ENOCONNECT. In order to break through the fence, the SSA logical disk must be opened in SSADISK_FENCEMODE and the SSADISK_ISALCMD ioctl operation used to issue the appropriate hardware command to break the fence condition.