02/03: hydra: node-129: Expose the SSDs as a new RAID 10 Btrfs array.

[Maxim Cournoyer]

apteryx pushed a commit to branch master
in repository maintenance.

commit 3c8c7e5af0d259d659f20f2156e73d66b7ef4091
Author: Maxim Cournoyer <maxim.cournoyer@gmail.com>
AuthorDate: Wed May 17 16:07:31 2023 -0400

    hydra: node-129: Expose the SSDs as a new RAID 10 Btrfs array.
    
    * hydra/deploy-node-129.scm (%btrfs-ssd-raid10-uuid): New variable.
    (%btrfs-pool-san): Relocate mount point to /mnt/btrfs-pool-san.
    (%btrfs-pool-ssd): New variable.
    (btrfs-subvolume-mount): Support a #:device-uuid argument.
    (node-129-os) [file-systems]: Add %btrfs-pool-ssd. Mount the
    @publish-mirror subvolume to /srv/publish/substitutes.
---
 hydra/deploy-node-129.scm | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/hydra/deploy-node-129.scm b/hydra/deploy-node-129.scm
index 2122e66..77f574c 100644
--- a/hydra/deploy-node-129.scm
+++ b/hydra/deploy-node-129.scm
@@ -47,20 +47,35 @@
 (define %common-btrfs-options '(("compress" . "zstd")
                                 ("space_cache" . "v2")))
 
+(define %btrfs-ssd-uuid "43c70fb3-c587-49b7-9c8d-23356d656fae")
+
 (define %btrfs-pool-san
   (file-system
     (device (uuid %btrfs-san-uuid))
-    (mount-point "/mnt/btrfs-pool")
+    (mount-point "/mnt/btrfs-pool-san")
     (create-mount-point? #t)
     (type "btrfs")
     (options (alist->file-system-options
               (cons '("subvolid" . "5")
                     %common-btrfs-options)))))
 
-(define (btrfs-subvolume-mount name mount-point)
-  "Return a file system to mount the Btrfs subvolume NAME at MOUNT-POINT."
+(define %btrfs-pool-ssd
   (file-system
-    (device (uuid %btrfs-san-uuid))
+    (device (uuid %btrfs-ssd-uuid))
+    (mount-point "/mnt/btrfs-pool-ssd")
+    (create-mount-point? #t)
+    (type "btrfs")
+    (options (alist->file-system-options
+              (cons '("subvolid" . "5")
+                    %common-btrfs-options)))))
+
+(define* (btrfs-subvolume-mount name mount-point
+                                #:key (device-uuid %btrfs-san-uuid))
+  "Return a file system to mount the Btrfs subvolume NAME at
+MOUNT-POINT.  DEVICE-UUID can be provided to use a different Btrfs file
+system than the default one hosted on the SAN storage."
+  (file-system
+    (device (uuid device-uuid))
     (mount-point mount-point)
     (create-mount-point? #t)
     (type "btrfs")
@@ -172,10 +187,20 @@ devices {
                       (mount-point "/boot/efi2")
                       (device (uuid "FCDB-FA3A" 'fat)) ;/dev/sdb2
                       (type "vfat"))
+
                      %btrfs-pool-san   ;for convenience
                      (btrfs-subvolume-mount "@root"       "/")
                      (btrfs-subvolume-mount "@home"       "/home")
                      (btrfs-subvolume-mount "@cache"      "/var/cache")
+
+                     %btrfs-pool-ssd
+                     ;; The renameat2 trick only works on the parent
+                     ;; of an active mount point, not on the mount
+                     ;; point itself, so introduce a 'publish' parent
+                     ;; directory.
+                     (btrfs-subvolume-mount "@publish-mirror"
+                                            "/srv/publish/substitutes"
+                                            #:device-uuid %btrfs-ssd-uuid)
                      %base-file-systems))
       (services
        (cons* (simple-service 'copy-kernel+initrd-to-/boot