[PATCH 2/4] README: Adjust and add btrfs testing information

[Gabriel Niebler <gniebler@suse.com>]

The system preparation info for btrfs specific tests was a little outdated,
as many tests require at least 5 indepedent scratch disks, which should be
of the same size and at least 10GB each. This patch fixes that.

There are also a few places in the README that assume the FS under test is XFS.
This changes these lines to extend to other filesystems,
to clarify this is an option.

Signed-off-by: Gabriel Niebler <gniebler@suse.com>
---
 README | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/README b/README
index 7e36905e..65e7ed7b 100644
--- a/README
+++ b/README
@@ -34,7 +34,8 @@ ______________________
 
 Preparing system for tests:
 
-    - compile XFS into your kernel or load XFS modules
+    - If you wish to test XFS, compile XFS into your kernel or load XFS modules,
+      same for btrfs.
     - install administrative tools specific to the filesystem you wish to test
     - If you wish to run the udf components of the suite install
       mkudffs. Also download and build the Philips UDF Verification Software
@@ -42,9 +43,9 @@ Preparing system for tests:
       binary to xfstests/src/. If you wish to disable UDF verification test
       set the environment variable DISABLE_UDF_TEST to 1.
 
-    - create one or two partitions to use for testing
+    - create one or more partitions to use for testing
         - one TEST partition
-            - format as XFS, mount & optionally populate with
+            - format as XFS (or FS of choice), mount & optionally populate with
               NON-IMPORTANT stuff
         - one SCRATCH partition (optional)
             - leave empty and expect this partition to be clobbered
@@ -52,12 +53,13 @@ Preparing system for tests:
               not be run.
               (SCRATCH and TEST must be two DIFFERENT partitions)
               OR
-        - for btrfs only: some btrfs test cases will need 3 or more independent
-              SCRATCH disks which should be set using SCRATCH_DEV_POOL (for eg:
-              SCRATCH_DEV_POOL="/dev/sda /dev/sdb /dev/sdc") with which
-              SCRATCH_DEV should be unused by the tester, and for the legacy
-              support SCRATCH_DEV will be set to the first disk of the
-              SCRATCH_DEV_POOL by xfstests script.
+        - for btrfs only: some btrfs test cases will need up to 5 independent,
+              equally sized SCRATCH disks of at least 10GB each, which should be
+              set using SCRATCH_DEV_POOL
+              (e.g.: SCRATCH_DEV_POOL="/dev/sda /dev/sdb /dev/sdc …"),
+              in which case SCRATCH_DEV should be unset by the tester, and for
+              legacy support SCRATCH_DEV will be set to the first disk of the
+              SCRATCH_DEV_POOL by the xfstests scripts.
 
     - setup your environment
 	Quick start:
@@ -69,7 +71,8 @@ Preparing system for tests:
         - setenv TEST_DIR "mount point of TEST PARTITION"
 	- optionally:
              - setenv SCRATCH_DEV "device containing SCRATCH PARTITION" OR
-               (btrfs only) setenv SCRATCH_DEV_POOL "to 3 or more SCRATCH disks for
+               (btrfs only) setenv SCRATCH_DEV_POOL "3 or more (ideally 5)
+               SCRATCH disks (ideally of equal size and at least 10GB each) for
                testing btrfs raid concepts"
              - setenv SCRATCH_MNT "mount point for SCRATCH PARTITION"
              - setenv TAPE_DEV "tape device for testing xfsdump"
@@ -143,7 +146,7 @@ Preparing system for tests:
     - if testing xfsdump, make sure the tape devices have a
       tape which can be overwritten.
 
-    - make sure $TEST_DEV is a mounted XFS partition
+    - make sure $TEST_DEV is a mounted XFS (or FS of choice) partition
     - make sure that $SCRATCH_DEV or $SCRATCH_DEV_POOL contains nothing useful
 
 Running tests:
-- 
2.35.1