diff options
author | Jasper Ras <jras@hostnet.nl> | 2025-01-19 21:14:51 +0100 |
---|---|---|
committer | Jasper Ras <jras@hostnet.nl> | 2025-01-19 21:14:51 +0100 |
commit | 9642cd7ae24f0ba79ce5647c709b35ae8f06a285 (patch) | |
tree | ae25c3b0db7ae4c23186b294c6d000073f085c2d /3 Resources/Linux/Device mapper.md | |
parent | 969b96c2531fb986f6c7f21fd544391b439defd7 (diff) |
vault backup: 2025-01-19 21:14:51
Diffstat (limited to '3 Resources/Linux/Device mapper.md')
-rw-r--r-- | 3 Resources/Linux/Device mapper.md | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/3 Resources/Linux/Device mapper.md b/3 Resources/Linux/Device mapper.md new file mode 100644 index 0000000..059a0d1 --- /dev/null +++ b/3 Resources/Linux/Device mapper.md @@ -0,0 +1,28 @@ +#linux #device-mapper + +--- +Device mapper is a kernel driver to map physical block devices to virtual ones; this means that for example we can have many physical devices be represented by a single virtual one (linear mapping). + +How does it work? +[[1 projects/Inwerken Mohammed/TODO]] +What is its function in relation to multipath? + +Logical devices using device-mapper can be managed using `man 8 dmsetup` +``` +[jasras@n04.compute.vps2-lej1 ~]$ sudo dmsetup info 3600a098038314d736724566a67346538 +Name: 3600a098038314d736724566a67346538 +State: ACTIVE +Read Ahead: 256 +Tables present: LIVE +Open count: 1 +Event number: 3 +Major, minor: 253, 12 +Number of targets: 1 +UUID: mpath-3600a098038314d736724566a67346538 +``` + +If dmsetup cannot remove a device because a process still has it open, but lsof does not show any processes that open it, use `-f` which replaces the device with a fake that rejects all I/O. + +--- +[device-mapper](https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/logical_volume_manager_administration/device_mapper#device_mapper) +[dmsetup](https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/7/html/logical_volume_manager_administration/dmsetup#dmsetup)
\ No newline at end of file |