[dm-devel] multipath-tools : A way needless to restart multipathd damon while attaching new device to host which met a path failure

[Gechangwei]

Hi,

I encountered an issue that devmapper disappeared while the multipathd dameon was restarted.

Digging into the root cause of preceding issue, I found storage path failure while restarting the multipathd daemon. It seems unreasonable, because the storage path may recover in the future.

When using multipath-tools to create device mapper, I configured “blacklist section” and “blacklist exception section”, which meets my requirement that only a small part of SCSI disk can be used underneath a device mapper.

After restarting the multipathd daemon, the device mapper of path failure disappears and it won’t comeback even the storage paths recover. So the file system on that devmapper can’t be available.

I wonder that if there is a solution that a device mapper of path failure can come back to active even I restart the multipathd daemon?

If such a solution exists, it will be marvelous

If not, I propose a userland interface to add blacklist exception dynamically. After the blacklist exception is added to “conf”, “multipathd add map $map” and “multipathd add path” can be used to add new map and path.

In a nutshell, we can dynamically add elist, map and paths respectively. And multipathd damon is not necessary to restart due to preceding solution.

Any experts of DM have any comments on my solution and the issue I faced with?


Your reply is very important to me.

Thanks.

BR.

Chauncey Ge
-------------------------------------------------------------------------------------------------------------------------------------
本邮件及其附件含有杭州华三通信技术有限公司的保密信息，仅限于发送给上面地址中列出
的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、
或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本
邮件！
This e-mail and its attachments contain confidential information from H3C, which is
intended only for the person or entity whose address is listed above. Any use of the
information contained herein in any way (including, but not limited to, total or partial
disclosure, reproduction, or dissemination) by persons other than the intended
recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender
by phone or email immediately and delete it!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/dm-devel/attachments/20160523/ab091317/attachment.htm>