<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <style>body { line-height: 1.5; }blockquote { margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em; }p { margin-top: 0px; margin-bottom: 0px; }div.foxdiv20170228200925061453 { }body { font-size: 10.5pt; font-family: 'Times New Roman'; color: rgb(0, 0, 0); line-height: 1.5; }</style> </head> <body> <div> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;">Hi, </pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;"> everyone</pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;"> In my testing in the use of 3Par storage device, when a LUN changes LUN number</pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;"> multipathd can not receive the uevent and can not disable access to the device. </pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;"> but for HP 6300 storage device, it can receive the uevent and disable access to the device. </pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;">So I think 3Par storage device don't support the case.</pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;">Now I don't have a right way to deal with the case. Thanks for your advise.</pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;"> </pre> <pre style="line-height: 32px; margin: 0cm 0cm 0.0001pt;">root@ubuntu98:~# udevadm monitor monitor will print the received events for: UDEV - the event which udev sends out after rule processing KERNEL - the kernel uevent KERNEL[68031.677399] change /devices/virtual/block/dm-1 (block) UDEV [68031.711148] change /devices/virtual/block/dm-1 (block) KERNEL[68032.678563] change /devices/virtual/block/dm-1 (block) UDEV [68032.705265] change /devices/virtual/block/dm-1 (block) KERNEL[68033.681120] change /devices/virtual/block/dm-1 (block) UDEV [68033.709744] change /devices/virtual/block/dm-1 (block) KERNEL[68035.682421] change /devices/virtual/block/dm-1 (block) KERNEL[68051.693362] change /devices/virtual/block/dm-2 (block) UDEV [68051.722144] change /devices/virtual/block/dm-2 (block) KERNEL[68052.694393] change /devices/virtual/block/dm-2 (block) KERNEL[68052.694761] change /devices/virtual/block/dm-2 (block) UDEV [68052.721103] change /devices/virtual/block/dm-2 (block) root@ubuntu98:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04 LTS Release: 16.04 Codename: xenial </pre> </div> <div> </div> <hr style="width: 210px; height: 1px;" color="#b5c4df" size="1" align="left"> <div> <div style="margin: 10px; font-size: 10pt;"> <div style="font-size: 16px;">All the best wishes for you.</div> <div style="font-size: 16px;">zhangguanghui</div> </div> </div> <blockquote style="margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em;"> <div> </div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"> <div style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; FONT-SIZE: 12px;FONT-FAMILY:tahoma;COLOR:#000000; BACKGROUND: #efefef; PADDING-BOTTOM: 8px; PADDING-TOP: 8px"> <div>From: <a href="mailto:dm-devel-bounces@redhat.com">dm-devel-bounces@redhat.com</a></div> <div>Date: 2016-11-04 23:32</div> <div>To: <a href="mailto:hare@suse.de">Hannes Reinecke</a></div> <div>CC: <a href="mailto:dm-devel@redhat.com">dm-devel@redhat.com</a></div> <div>Subject: Re: [dm-devel] [PATCH 09/10] add disable_changed_wwids option</div> </div> </div> <div> <div class="FoxDiv20170228200925061453"> On Sun, Oct 30, 2016 at 02:54:14PM +0100, Hannes Reinecke wrote: > On 10/29/2016 04:55 AM, Benjamin Marzinski wrote: > >If a LUN on a storage device gets remapped while in-use by multipath, > >it's possible that the multipath device will continue writing to this > >new LUN, causing corruption. This is not multipath's fault (users > >should go remapping in-use LUNs), but it's possible for multipath to > >detect this and disable IO to the device. If disable_changed_wwids > >is set to "yes", multipathd will detect when a LUN changes wwids when it > >receives the uevent for this, and will disable access to the device > >until the LUN is mapped back. > > > >Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> > >--- > > libmultipath/config.c | 1 + > > libmultipath/config.h | 1 + > > libmultipath/defaults.h | 1 + > > libmultipath/dict.c | 4 ++++ > > libmultipath/discovery.c | 15 +++++++-------- > > libmultipath/discovery.h | 1 + > > libmultipath/structs.h | 1 + > > multipathd/main.c | 32 ++++++++++++++++++++++++++++++++ > > 8 files changed, 48 insertions(+), 8 deletions(-) > > > Hmm. Not sure if the really buys us anything. By the time we process the > uevent it might already be too late, and I/O might already have been written > to that device. > I do agree on the warning, though. I have taken some pains to try to explain this short-coming to the customer who filed this bugzilla. The good news is that in practice, the device ususally goes down when you are remapping the LUN, and you disable the device before it ever comes back. In my testing, I wasn't able to actually ever write to the wrong device with disable_changed_wwids enabled, but I do agree that you have the potential to race here. -Ben > > Cheers, > > Hannes > -- > Dr. Hannes Reinecke zSeries & Storage > hare@suse.de +49 911 74053 688 > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg > GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) > > -- > dm-devel mailing list > dm-devel@redhat.com > <a href="https://www.redhat.com/mailman/listinfo/dm-devel">https://www.redhat.com/mailman/listinfo/dm-devel</a> -- dm-devel mailing list dm-devel@redhat.com <a href="https://www.redhat.com/mailman/listinfo/dm-devel">https://www.redhat.com/mailman/listinfo/dm-devel</a> </div> </div> </blockquote> ------------------------------------------------------------------------------------------------------------------------------------- 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. 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