I just realized that I was in a different situation that you are in. We had multiple Linux users sharing a disk on an LVM R/O, but what you have is one R/W and multiple R/O. If the system with R/W makes change, the R/O system's file system will not have means to sync up. So even if you manage to solve your current problems, you could still end up with IO errors on the Linux that's linking R/O. Is there a particular reason why you need to share Linux data via minidisk links? Could a NFS share do the same job?
Tomas -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Shumate, Scott Sent: Tuesday, November 18, 2014 3:56 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: device-mapper: reload ioctl on failed Thanks for the reply Thomas. I'm going to pass this on to our Linux guys, this is their arena. I'm trying to help them trouble shoot. I'm not keen on making the disk mw. I'm with you on that one. It should work by linking it r/o and mount the volume group r/o on the linux side. Works fine in our QA environment. Just fails on our test environment. Thanks Scott -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Pavelka, Tomas Sent: Tuesday, November 18, 2014 2:27 AM To: LINUX-390@VM.MARIST.EDU Subject: Re: device-mapper: reload ioctl on failed > It works if I attach the mini-disk was multi-write. This is not what we want > but it works. Any ideas? A lot of speculation on my part follows. Again I will point to Red Hat as the more informed party. The bug I dealt with before seems very similar to what you are experiencing. There were functions in the LVM code used for volume initialization that came in two variants: the read write variant would write metadata to the volume during initialization while the read only variant would not try to write anything. The cause of the bug was that someone forgot to call the RO variant when the disk was linked RO and the RW variant tried to write to the disk and failed which in turn caused the whole initialization to fail and the volume was not brought online. If your case is similar, then linking the minidisk MW would allow the initialization logic on the disk that is supposed to read to write to the disk. I assume that you are using an ext type file system and I am also assuming that Linux does not support the RESERVE/RELEASE function there (if there is someone who knows better please correct me). This means that the two Linuxes sharing the disk can write to the disk at the same time. You may get lucky and this will work or you may end up with corrupted LVM metadata or worse. Before you proceed with this check how important the data on those disks are, what are your skills regarding recovery of LVM disks with corrupted metadata and whether you have usable backups. Even if the data on those disks are not valuable, corrupted LVM metadata could make debugging your original problem more complicated. The safe rule of MW is to never use it unless you have a very good idea about what you are doing. HTH, Tomas ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ The information in this transmission may contain proprietary and non-public information of BB&T or its affiliates and may be subject to protection under the law. The message is intended for the sole use of the individual or entity to which it is addressed. If you are not the intended recipient, you are notified that any use, distribution or copying of the message is strictly prohibited. If you received this message in error, please delete the material from your system without reading the content and notify the sender immediately of the inadvertent transmission. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
