diff --git a/src/aks-preview/azext_aks_preview/azurecontainerstorage/_helpers.py b/src/aks-preview/azext_aks_preview/azurecontainerstorage/_helpers.py
index aa2a9a9ccd..e0592e61e5 100644
--- a/src/aks-preview/azext_aks_preview/azurecontainerstorage/_helpers.py
+++ b/src/aks-preview/azext_aks_preview/azurecontainerstorage/_helpers.py
@@ -30,12 +30,13 @@
     delete_role_assignments,
 )
 from azure.cli.core.azclierror import UnknownError
-from cachetools import cached
-from cachetools.keys import hashkey
 from knack.log import get_logger
 
 logger = get_logger(__name__)
 
+# Global cache to store VM SKU information.
+vm_sku_details_cache = {}
+
 
 def validate_storagepool_creation(
     cmd,
@@ -453,15 +454,11 @@ def generate_vm_sku_cache_for_region(cli_ctx, location=None):
             if entry.name == 'NvmeDiskSizeInMiB':
                 nvme_enabled = True
 
-        vm_sku_details(sku_name, cpu_value, nvme_enabled)
+            vm_sku_details_cache[sku_name] = (cpu_value, nvme_enabled)
 
 
-@cached(
-    cache={},
-    key=lambda sku_name, cpu_value=None, nvme_enabled=None: hashkey(sku_name)
-)
-def vm_sku_details(sku_name, cpu_value=None, nvme_enabled=None):  # pylint: disable=unused-argument
-    return cpu_value, nvme_enabled
+def get_vm_sku_details(sku_name):
+    return vm_sku_details_cache.get(sku_name)
 
 
 def _get_ephemeral_nvme_cpu_value_based_on_vm_size_perf_tier(nodepool_skus, perf_tier):
@@ -472,7 +469,11 @@ def _get_ephemeral_nvme_cpu_value_based_on_vm_size_perf_tier(nodepool_skus, perf
     elif perf_tier.lower() == CONST_EPHEMERAL_NVME_PERF_TIER_PREMIUM.lower():
         multiplication_factor = 0.5
     for vm_size in nodepool_skus:
-        number_of_cores, _ = vm_sku_details(vm_size.lower())
+        number_of_cores, _ = get_vm_sku_details(vm_size.lower())
+        if number_of_cores is None:
+            raise UnknownError(
+                f"Unable to find details for virtual machine size {vm_size}."
+            )
         if number_of_cores != -1:
             if cpu_value == -1:
                 cpu_value = number_of_cores * multiplication_factor
diff --git a/src/aks-preview/azext_aks_preview/azurecontainerstorage/_validators.py b/src/aks-preview/azext_aks_preview/azurecontainerstorage/_validators.py
index 66a94ba5eb..29e7433b7d 100644
--- a/src/aks-preview/azext_aks_preview/azurecontainerstorage/_validators.py
+++ b/src/aks-preview/azext_aks_preview/azurecontainerstorage/_validators.py
@@ -22,7 +22,7 @@
     CONST_STORAGE_POOL_TYPE_EPHEMERAL_DISK,
 )
 from azext_aks_preview.azurecontainerstorage._helpers import (
-    vm_sku_details
+    get_vm_sku_details
 )
 from azure.cli.core.azclierror import (
     ArgumentUsageError,
@@ -516,7 +516,11 @@ def _validate_nodepools(  # pylint: disable=too-many-branches,too-many-locals
                     )
             vm_size = agentpool.get("vm_size")
             if vm_size is not None:
-                cpu_value, nvme_enabled = vm_sku_details(vm_size.lower())
+                cpu_value, nvme_enabled = get_vm_sku_details(vm_size.lower())
+                if cpu_value is None or nvme_enabled is None:
+                    raise UnknownError(
+                        f'Unable to find details for virtual machine size {vm_size}.'
+                    )
                 if cpu_value < 0:
                     raise UnknownError(
                         f'Unable to determine number of cores in node pool: {pool_name}, node size: {vm_size}'
diff --git a/src/aks-preview/azext_aks_preview/tests/latest/test_validators.py b/src/aks-preview/azext_aks_preview/tests/latest/test_validators.py
index 9a7cdb6f68..b83b11a7ad 100644
--- a/src/aks-preview/azext_aks_preview/tests/latest/test_validators.py
+++ b/src/aks-preview/azext_aks_preview/tests/latest/test_validators.py
@@ -875,16 +875,7 @@ def test_valid_disable(self):
 class TestValidateEnableAzureContainerStorage(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
-        cls.mock_cache = {
-            ('standard_l8s_v3',): (8, True),
-            ('standard_d2s_v2',): (2, False),
-            ('standard_d2pds_v6',): (2, True),
-            ('standard_ds1_v2',): (1, False),
-            ('standard_m8-2ms',): (2, False),
-            ('standard_b2s',): (2, False),
-        }
-
-        def side_effect_fn(sku_name, cpu_val=None, nvme=None):
+        def side_effect_fn(sku_name):
             if sku_name == "standard_l8s_v3":
                 return 8, True
             elif sku_name == "standard_d2s_v2":
@@ -900,7 +891,7 @@ def side_effect_fn(sku_name, cpu_val=None, nvme=None):
 
             return None, None
 
-        cls.patcher = patch('azext_aks_preview.azurecontainerstorage._validators.vm_sku_details')
+        cls.patcher = patch('azext_aks_preview.azurecontainerstorage._validators.get_vm_sku_details')
         cls.mock_fn = cls.patcher.start()
         cls.mock_fn.side_effect = side_effect_fn