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--- mergerfs:remove_a_data_disk [2025/05/12 21:34] – peter
+++ mergerfs:remove_a_data_disk [2025/05/12 22:02] (current) – peter
@@ Line 1: / Line 1: @@
 ====== MergerFS - Remove a data disk ======
+===== View the current setup =====
+Install the xattr utility tool:
+<code bash>
+apt install python-xattr
+</code>
+Assuming the root of the mergerfs filesystem is /storage, use xattrs to view the pseudo .mergerfs file:
+<code bash>
+cd /storage
+xattr -l .mergerfs
+</code>
+returns:
+<code>
+user.mergerfs.srcmounts: /mnt/data/disk01:/mnt/data/disk02:/mnt/data/disk03:/mnt/data/disk04:/mnt/data/disk05
+user.mergerfs.minfreespace: 21474836480
+user.mergerfs.moveonenospc: true
+user.mergerfs.policies: all,eplfs,eplus,epmfs,erofs,ff,lfs,lus,mfs,newest,rand
+user.mergerfs.version: 2.13.1
+user.mergerfs.pid: 91089
+user.mergerfs.category.action: all
+user.mergerfs.category.create: eplfs
+user.mergerfs.category.search: ff
+user.mergerfs.func.access: ff
+user.mergerfs.func.chmod: all
+user.mergerfs.func.chown: all
+user.mergerfs.func.create: eplfs
+user.mergerfs.func.getattr: ff
+user.mergerfs.func.getxattr: ff
+user.mergerfs.func.link: all
+user.mergerfs.func.listxattr: ff
+user.mergerfs.func.mkdir: eplfs
+user.mergerfs.func.mknod: eplfs
+user.mergerfs.func.open: ff
+user.mergerfs.func.readlink: ff
+user.mergerfs.func.removexattr: all
+user.mergerfs.func.rename: all
+user.mergerfs.func.rmdir: all
+user.mergerfs.func.setxattr: all
+user.mergerfs.func.symlink: eplfs
+user.mergerfs.func.truncate: all
+user.mergerfs.func.unlink: all
+user.mergerfs.func.utimens: all
+</code>
+<WRAP info>
+**NOTE:**  This shows that there are 5 disks in the pool, namely:
+  * /mnt/data/disk01
+  * /mnt/data/disk02
+  * /mnt/data/disk03
+  * /mnt/data/disk04
+  * /mnt/data/disk05
+All of options shown can be set in real time without unmounting and re-mounting the mergerfs pool via the runtime options.
+</WRAP>
+----
+===== Remove a disk =====
+From within the root of the mergerfs filesystem (eg. /storage)
+<code bash>
+xattr -w user.mergerfs.srcmounts '-/mnt/data/disk05' .mergerfs
+or, for removing two disks use:
+xattr -w user.mergerfs.srcmounts '-/mnt/data/disk04:/mnt/data/disk05' .mergerfs
+</code>
+<WRAP info>
+**NOTE:**  This will remove disk04 and disk05 from the current srcmounts.
+  * This modifies the pool in real time - no need to unmount, or stop any services.
+</WRAP>
+====
+----
 From within the root of the mergerfs filesystem (eg. /storage)