diff --git a/rpmbuild/copr_rpmbuild/builders/mock.py b/rpmbuild/copr_rpmbuild/builders/mock.py
index b3cc31461..4204c1796 100644
--- a/rpmbuild/copr_rpmbuild/builders/mock.py
+++ b/rpmbuild/copr_rpmbuild/builders/mock.py
@@ -42,6 +42,10 @@ def __init__(self, task, sourcedir, resultdir, config):
         self.macros = macros_for_task(task, config)
         self.uniqueext = get_mock_uniqueext()
         self.allow_user_ssh = task.get("allow_user_ssh")
+        self.tags = task.get("tags", [])
+        self.max_fs_size = "140g"
+        if "on_demand_powerful" in self.tags:
+            self.max_fs_size = "280g"
 
     def run(self):
         open(self.logfile, 'w').close() # truncate logfile
@@ -82,6 +86,7 @@ def render_config_template(self):
             copr_build_id=self.build_id,
             isolation=self.isolation,
             macros=self.macros,
+            max_fs_size=self.max_fs_size,
         )
 
     def produce_srpm(self, spec, sources, resultdir):
diff --git a/rpmbuild/copr_rpmbuild/providers/base.py b/rpmbuild/copr_rpmbuild/providers/base.py
index 8250e4036..fdf062eaf 100644
--- a/rpmbuild/copr_rpmbuild/providers/base.py
+++ b/rpmbuild/copr_rpmbuild/providers/base.py
@@ -51,6 +51,10 @@ def __init__(self, source_dict, config, macros=None, task=None):
             if e.errno != errno.EEXIST:
                 raise
 
+        self.max_fs_size = "140g"
+        if task is not None and "on_demand_powerful" in task.get("tags", []):
+            self.max_fs_size = "280g"
+
         # Change home directory to workdir and create .rpmmacros there
         os.environ["HOME"] = self.workdir
         self.create_rpmmacros()
@@ -130,7 +134,7 @@ def render_mock_config_template(self, template_name):
         """
         jinja_env = Environment(loader=FileSystemLoader(CONF_DIRS))
         template = jinja_env.get_template(template_name)
-        return template.render(macros=self.macros)
+        return template.render(macros=self.macros, max_fs_size=self.max_fs_size)
 
     def produce_srpm(self):
         """
diff --git a/rpmbuild/copr_rpmbuild/providers/custom.py b/rpmbuild/copr_rpmbuild/providers/custom.py
index ce5469a62..95673dff2 100644
--- a/rpmbuild/copr_rpmbuild/providers/custom.py
+++ b/rpmbuild/copr_rpmbuild/providers/custom.py
@@ -51,6 +51,7 @@ def render_mock_config_template(self, *_args):
             chroot=self.chroot,
             repos=self.repos,
             macros=self.macros,
+            max_fs_size=self.max_fs_size,
         )
 
     def produce_srpm(self):
diff --git a/rpmbuild/mock-custom-build.cfg.j2 b/rpmbuild/mock-custom-build.cfg.j2
index c71e85609..aa8fb1ec0 100644
--- a/rpmbuild/mock-custom-build.cfg.j2
+++ b/rpmbuild/mock-custom-build.cfg.j2
@@ -15,6 +15,7 @@ config_opts["root"] = "copr-custom-" + config_opts["root"]
 # Important e.g. to keep '/script' file available across several
 # /bin/mock calls (when tmpfs_enable is on).
 config_opts['plugin_conf']['tmpfs_opts']['keep_mounted'] = True
+config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '{{ max_fs_size }}'
 
 {%- for key, value in macros.items() %}
 config_opts['macros']['{{ key }}'] = '{{ value }}'
diff --git a/rpmbuild/mock.cfg.j2 b/rpmbuild/mock.cfg.j2
index 25f3bbf19..f4bb7d9bc 100644
--- a/rpmbuild/mock.cfg.j2
+++ b/rpmbuild/mock.cfg.j2
@@ -3,6 +3,7 @@ include('/etc/mock/{{ chroot }}.cfg')
 config_opts.setdefault('plugin_conf', {})
 config_opts['plugin_conf'].setdefault('tmpfs_opts', {})
 config_opts['plugin_conf']['tmpfs_opts']['keep_mounted'] = True
+config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '{{ max_fs_size }}'
 
 {% if buildroot_pkgs %}
 config_opts['chroot_additional_packages'] = '{{ buildroot_pkgs| join(" ") }}'
diff --git a/rpmbuild/tests/test_mock.py b/rpmbuild/tests/test_mock.py
index fe43e0bda..7c5915176 100644
--- a/rpmbuild/tests/test_mock.py
+++ b/rpmbuild/tests/test_mock.py
@@ -146,6 +146,7 @@ def test_mock_config(self, call, f_mock_calls):
 config_opts.setdefault('plugin_conf', {})
 config_opts['plugin_conf'].setdefault('tmpfs_opts', {})
 config_opts['plugin_conf']['tmpfs_opts']['keep_mounted'] = True
+config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '140g'
 
 
 config_opts['chroot_additional_packages'] = 'pkg1 pkg2 pkg3'
@@ -164,6 +165,21 @@ def test_mock_config(self, call, f_mock_calls):
 
 """  # TODO: make the output nicer
 
+    @mock.patch("copr_rpmbuild.builders.mock.subprocess.call")
+    # pylint: disable-next=unused-argument, redefined-outer-name
+    def test_mock_config_hp_fs_size(self, call, f_mock_calls):
+        """ test that fs_size for performance builders is correctly set """
+        self.task["tags"] = ["blabla_tag", "on_demand_powerful"]
+        MockBuilder(self.task, self.sourcedir, self.resultdir,
+                    self.config).run()
+
+        #config = open(self.child_config, 'r').readlines()
+        with open(self.child_config, "r", encoding="utf-8") as f:
+            config = f.readlines()
+
+        config = ''.join(config)
+        assert "config_opts['plugin_conf']['tmpfs_opts']['max_fs_size'] = '280g'" in config
+
     @mock.patch("copr_rpmbuild.builders.mock.MockBuilder.prepare_configs")
     @mock.patch("copr_rpmbuild.builders.mock.MockBuilder.archive_configs")
     def test_mock_options(self, archive_configs, prep_configs, f_mock_calls):