diff --git a/server/disk_avail.go b/server/disk_avail.go
index b879330e850..e27c1a71cc1 100644
--- a/server/disk_avail.go
+++ b/server/disk_avail.go
@@ -11,7 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build !windows && !openbsd && !netbsd && !wasm
+//go:build !windows && !openbsd && !netbsd && !wasm && !illumos && !solaris
 
 package server
 
diff --git a/server/disk_avail_solaris.go b/server/disk_avail_solaris.go
new file mode 100644
index 00000000000..e0febd1fee3
--- /dev/null
+++ b/server/disk_avail_solaris.go
@@ -0,0 +1,38 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build illumos || solaris
+
+package server
+
+import (
+	"os"
+	"golang.org/x/sys/unix"
+)
+
+func diskAvailable(storeDir string) int64 {
+	var ba int64
+	if _, err := os.Stat(storeDir); os.IsNotExist(err) {
+		os.MkdirAll(storeDir, defaultDirPerms)
+	}
+	var fs unix.Statvfs_t
+	if err := unix.Statvfs(storeDir, &fs); err == nil {
+		// Estimate 75% of available storage.
+		ba = int64(uint64(fs.Frsize) * uint64(fs.Bavail) / 4 * 3)
+	} else {
+		// Used 1TB default as a guess if all else fails.
+		ba = JetStreamMaxStoreDefault
+	}
+	return ba
+}
+
diff --git a/server/pse/pse_solaris.go b/server/pse/pse_solaris.go
index 8e40d2ed306..f812ba487f5 100644
--- a/server/pse/pse_solaris.go
+++ b/server/pse/pse_solaris.go
@@ -1,4 +1,4 @@
-// Copyright 2015-2018 The NATS Authors
+// Copyright 2015-2025 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -10,14 +10,36 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+//
+// Copied from pse_openbsd.go
+
+//go:build illumos || solaris
 
 package pse
 
-// This is a placeholder for now.
-func ProcUsage(pcpu *float64, rss, vss *int64) error {
-	*pcpu = 0.0
-	*rss = 0
-	*vss = 0
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
 
+// ProcUsage returns CPU usage
+func ProcUsage(pcpu *float64, rss, vss *int64) error {
+	pidStr := fmt.Sprintf("%d", os.Getpid())
+	out, err := exec.Command("ps", "-o", "pcpu,rss,vsz", "-p", pidStr).Output()
+	if err != nil {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("ps call failed:%v", err)
+	}
+	lines := strings.Split(string(out), "\n")
+	if len(lines) < 2 {
+		*rss, *vss = -1, -1
+		return fmt.Errorf("no ps output")
+	}
+	output := lines[1]
+	fmt.Sscanf(output, "%f %d %d", pcpu, rss, vss)
+	*rss *= 1024 // 1k blocks, want bytes.
+	*vss *= 1024 // 1k blocks, want bytes.
 	return nil
 }
diff --git a/server/sysmem/mem_solaris.go b/server/sysmem/mem_solaris.go
new file mode 100644
index 00000000000..afba03641e5
--- /dev/null
+++ b/server/sysmem/mem_solaris.go
@@ -0,0 +1,37 @@
+// Copyright 2025 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build illumos || solaris
+
+package sysmem
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+const (
+	_SC_PHYS_PAGES = 500
+	_SC_PAGESIZE   = 11
+)
+
+func Memory() int64 {
+	pages, err := unix.Sysconf(_SC_PHYS_PAGES)
+	if err != nil {
+		return 0
+	}
+	pageSize, err := unix.Sysconf(_SC_PAGESIZE)
+	if err != nil {
+		return 0
+	}
+	return int64(pages) * int64(pageSize)
+}