Hi, I hope I am right here, if not, please let me know where would be a better place to ask. I have observed a problem on LVM based partitions when I change the paths through the SAN. Here my setup: I have a 3TB partition, coming from a SAN IBM DS4700, the same but smaller, for the operating system partition. Both presented to a xen host. On the data partition I have a LVM configured. There are four paths through the SAN for each of the disks. The host type on the DS4700 for the server is configured as LNXCLVMWARE, which as for the documentation should be the right one. # multipath -ll Pilot-Project-VMs (3600a0b800048b31000000ffd4a10fd7e) dm-1 IBM,1814 FAStT [size=280G][features=1 queue_if_no_path][hwhandler=1 rdac][rw] \_ round-robin 0 [prio=2][enabled] \_ 4:0:1:0 sdf 8:80 [active][ghost] \_ 3:0:1:0 sdg 8:96 [active][ghost] \_ round-robin 0 [prio=12][active] \_ 3:0:0:0 sdb 8:16 [active][ready] \_ 4:0:0:0 sdc 8:32 [active][ready] Pilot-Project-Data (3600a0b800048b31000000fbe49f962e5) dm-3 IBM,1814 FAStT [size=3.0T][features=1 queue_if_no_path][hwhandler=1 rdac][rw] \_ round-robin 0 [prio=2][enabled] \_ 4:0:1:1 sdh 8:112 [active][ghost] \_ 3:0:1:1 sdi 8:128 [active][ghost] \_ round-robin 0 [prio=12][enabled] \_ 3:0:0:1 sdd 8:48 [active][ready] \_ 4:0:0:1 sde 8:64 [active][ready] When I run a dd copy job, creating a file on the Operating system partition, e.g. dd if=7dev/zero of=/data/file then everything seems to be fine. I change the path through the SAN via the DS4700 management GUI, and the dd job keeps running as expected, so no problem without LVM. When I do the same on the LVM partition, then after some seconds, after I switch the preferred path through the SAN, then the LVM partiton becomes read-only, and the dd job dies. Then on the dom0, a fdisk -l /dev/mapper/3TB-Partion still shows output, but fdisk -l /dev/mapper/3TB--Partion-1 on the LVM device, just shows nothing. When I then shutdown the xen host, and do a: /etc/init.d/boot.lvm restart then fdisk -l /dev/mapper/3TB--Partion-1 on the LVM device, produces output again. However, the startup of the xen domU may still spit out errors, and the mounting of the device in the domU may still not work. I had to reboot the dom0 physical host to get the partition back in a working state. I do not have any kind of special configuration for the LVM device, I created it via yast2. Is there anything what I can do to prevent the LVM based partition to become read-only when a path in the SAN switches? If I need to provide more information let me know whats needed. kind regards Sebastian _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
