I've got a Debian Jessie system running Linux kernel 4.4-rc4 on AMD64 Phenom II X4 with 16gb of RAM. I've just replaced a bunch of failing 1Tb drives and my 320Gb boot drives with 2 x 4Tb disks and 2 x 500gb SSDs. Using LVM cache for a couple of areas and it's looking good so far. I've got the following LVM targets: # dmsetup targets cache v1.8.0 thin-pool v1.16.0 thin v1.16.0 raid v1.7.0 zero v1.1.0 mirror v1.14.0 snapshot-merge v1.4.0 snapshot-origin v1.9.0 snapshot v1.15.0 multipath v1.10.0 flakey v1.3.1 delay v1.2.1 crypt v1.14.1 striped v1.5.1 linear v1.2.1 error v1.3.0 And packages installed: libllvm3.5:amd64 1:3.5-10 liblvm2app2.2:amd64 2.02.111-2.2 liblvm2cmd2.02:amd64 2.02.111-2.2 lvm2 2.02.111-2.2 So now I want to monitor performance and cache usage. But I can't because: dmsetup status --target cache Fails with: The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVas2sZsZM8mw0VXDgx03ryaq351RUEL4j-cmeta" should be mangled but it contains blacklisted characters. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVbbcg3pVFZyDngdRLS4aECbc571Lyb5MI" should be mangled but it contains blacklisted characters. Command failed So I've looked at dmsetup man page and tried to run dmsetup mangle But it fails on all the LVM volumes with stuff like this: data-pete: LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVbbcg3pVFZyDngdRLS4aECbc571Lyb5MI: UUID in incorrect form. Unable to change device UUID. The device must be deactivated first. Command failed So when I do: umount /mnt/pete lvchange -an data/pete dmsetup mangle data/pete it bombs out. I've compiled the latest lvm2 tools, but it still dies: # /opt/lvm2/sbin/dmsetup --version Library version: 1.02.114-git (2015-12-05) Driver version: 4.34.0 So I have two questions: 1. How do I mangle the name properly? Do I need to reboot using a LiveCD of some sort? 2. And can we fix the failing of: dmsetup status --target-cache even when there are UUIDs that need de-mangling? I'm happy to test patches, versions, etc. THanks, John -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
