diff --git a/crates/ecstore/src/pools.rs b/crates/ecstore/src/pools.rs
index 3e7211895..e81cba0a7 100644
--- a/crates/ecstore/src/pools.rs
+++ b/crates/ecstore/src/pools.rs
@@ -1384,28 +1384,109 @@ impl SetDisks {
     }
 }
 
+fn is_disk_online_state(state: &str) -> bool {
+    // The disk state strings are produced from rustfs_utils::os::get_drive_stats or DiskError::to_string().
+    // Conventionally, online is "ok"/"online" (may evolve). Be conservative:
+    // - Treat empty as unknown -> include it (to avoid dropping capacity).
+    // - Exclude explicit offline-ish states.
+    let s = state.trim().to_lowercase();
+    if s.is_empty() {
+        return true;
+    }
+    if s.contains("offline") {
+        return false;
+    }
+    if s.contains("not found") || s.contains("disk not found") {
+        return false;
+    }
+    true
+}
+
+fn fallback_total_capacity(disks: &[rustfs_madmin::Disk]) -> usize {
+    disks
+        .iter()
+        .filter(|d| is_disk_online_state(&d.state))
+        .map(|d| d.total_space as usize)
+        .sum()
+}
+
+fn fallback_free_capacity(disks: &[rustfs_madmin::Disk]) -> usize {
+    disks
+        .iter()
+        .filter(|d| is_disk_online_state(&d.state))
+        .map(|d| d.available_space as usize)
+        .sum()
+}
+
 pub fn get_total_usable_capacity(disks: &[rustfs_madmin::Disk], info: &rustfs_madmin::StorageInfo) -> usize {
-    let mut capacity = 0;
+    // If backend info is missing or inconsistent, do a safe fallback to avoid reporting nonsense.
+    if info.backend.standard_sc_data.is_empty() {
+        return fallback_total_capacity(disks);
+    }
+
+    let mut capacity = 0usize;
+    let mut matched_any = false;
+
     for disk in disks.iter() {
-        if disk.pool_index < 0 || info.backend.standard_sc_data.len() <= disk.pool_index as usize {
+        if disk.pool_index < 0 {
             continue;
         }
-        if (disk.disk_index as usize) < info.backend.standard_sc_data[disk.pool_index as usize] {
+        let pool_idx = disk.pool_index as usize;
+        if info.backend.standard_sc_data.len() <= pool_idx {
+            continue;
+        }
+
+        let usable_disks_per_set = info.backend.standard_sc_data[pool_idx];
+        if usable_disks_per_set == 0 {
+            continue;
+        }
+
+        if (disk.disk_index as usize) < usable_disks_per_set {
+            matched_any = true;
             capacity += disk.total_space as usize;
         }
     }
-    capacity
+
+    if matched_any {
+        capacity
+    } else {
+        // Even if standard_sc_data exists, it might not match disk indexes due to upstream bugs.
+        // Fallback to summing all online disks to prevent under-reporting.
+        fallback_total_capacity(disks)
+    }
 }
 
 pub fn get_total_usable_capacity_free(disks: &[rustfs_madmin::Disk], info: &rustfs_madmin::StorageInfo) -> usize {
-    let mut capacity = 0;
+    if info.backend.standard_sc_data.is_empty() {
+        return fallback_free_capacity(disks);
+    }
+
+    let mut capacity = 0usize;
+    let mut matched_any = false;
+
     for disk in disks.iter() {
-        if disk.pool_index < 0 || info.backend.standard_sc_data.len() <= disk.pool_index as usize {
+        if disk.pool_index < 0 {
             continue;
         }
-        if (disk.disk_index as usize) < info.backend.standard_sc_data[disk.pool_index as usize] {
+        let pool_idx = disk.pool_index as usize;
+        if info.backend.standard_sc_data.len() <= pool_idx {
+            continue;
+        }
+
+        let usable_disks_per_set = info.backend.standard_sc_data[pool_idx];
+        if usable_disks_per_set == 0 {
+            continue;
+        }
+
+        if (disk.disk_index as usize) < usable_disks_per_set {
+            matched_any = true;
             capacity += disk.available_space as usize;
         }
     }
-    capacity
+
+    if matched_any {
+        capacity
+    } else {
+        fallback_free_capacity(disks)
+    }
 }
diff --git a/crates/ecstore/src/set_disk.rs b/crates/ecstore/src/set_disk.rs
index 52d33c3fe..389e3f16d 100644
--- a/crates/ecstore/src/set_disk.rs
+++ b/crates/ecstore/src/set_disk.rs
@@ -6817,10 +6817,17 @@ async fn get_storage_info(disks: &[Option<DiskStore>], eps: &[Endpoint]) -> rust
     let mut disks = get_disks_info(disks, eps).await;
     disks.sort_by(|a, b| a.total_space.cmp(&b.total_space));
 
+    // Provide minimal backend shape for callers. Do NOT guess parity here since it belongs to higher-level config.
+    // Missing/empty standard_sc_data will be handled by capacity fallback logic.
+    let drives_per_set = vec![eps.len()];
+    let total_sets = vec![1];
+
     rustfs_madmin::StorageInfo {
         disks,
         backend: rustfs_madmin::BackendInfo {
             backend_type: rustfs_madmin::BackendByte::Erasure,
+            drives_per_set,
+            total_sets,
             ..Default::default()
         },
     }