The mdadm program controls Linux md devices (software RAID arrays)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

83 lines
2.6 KiB

From fea026b4849182fc8413014c81456e7215af28d9 Mon Sep 17 00:00:00 2001
From: Mateusz Kusiak <>
Date: Wed, 23 Mar 2022 15:05:19 +0100
Subject: [PATCH 03/12] Grow_reshape: Add r0 grow size error message and update
Grow size on r0 is not supported for imsm and native metadata.
Add proper error message.
Update man for proper use of --size.
Signed-off-by: Mateusz Kusiak <>
Signed-off-by: Jes Sorensen <>
Grow.c | 6 ++++++ | 19 ++++++++++++-------
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/Grow.c b/Grow.c
index 9a947204..aa72490b 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1998,6 +1998,12 @@ int Grow_reshape(char *devname, int fd,
goto release;
+ if (array.level == 0) {
+ pr_err("Component size change is not supported for RAID0\n");
+ rv = 1;
+ goto release;
+ }
if (reshape_super(st, s->size, UnSet, UnSet, 0, 0, UnSet, NULL,
c->verbose > 0)) {
diff --git a/ b/
index be902dba..e2a42425 100644
--- a/
+++ b/
@@ -459,7 +459,8 @@ number of spare devices.
.BR \-z ", " \-\-size=
-Amount (in Kilobytes) of space to use from each drive in RAID levels 1/4/5/6.
+Amount (in Kilobytes) of space to use from each drive in RAID levels 1/4/5/6/10
+and for RAID 0 on external metadata.
This must be a multiple of the chunk size, and must leave about 128Kb
of space at the end of the drive for the RAID superblock.
If this is not specified
@@ -478,10 +479,19 @@ To guard against this it can be useful to set the initial size
slightly smaller than the smaller device with the aim that it will
still be larger than any replacement.
+This option can be used with
+.B \-\-create
+for determining initial size of an array. For external metadata,
+it can be used on a volume, but not on a container itself.
+Setting initial size of
+.B RAID 0
+array is only valid for external metadata.
This value can be set with
.B \-\-grow
-for RAID level 1/4/5/6 though
+for RAID level 1/4/5/6/10 though
DDF arrays may not be able to support this.
+RAID 0 array size cannot be changed.
If the array was created with a size smaller than the currently
active drives, the extra space can be accessed using
.BR \-\-grow .
@@ -501,11 +511,6 @@ problems the array can be made bigger again with no loss with another
.B "\-\-grow \-\-size="
-This value cannot be used when creating a
-such as with DDF and IMSM metadata, though it perfectly valid when
-creating an array inside a container.
.BR \-Z ", " \-\-array\-size=
This is only meaningful with