[LEDE-DEV] [RFC 3/3] config: ext4: use 1K blocks by default to support online resize2fs

Jo-Philipp Wich jo at mein.io
Sat Oct 15 16:59:44 PDT 2016

Commit fe20272ab16068765a191f3a846f30f977bc7669 (SVN r40924) introduced
support for specifying ext4 blocksizes but silently switched the implicit
1K value to 4K by default without also adjusting the default partition size.

The current default size of 256MB in conjunction with 4K blocks produces an
ext4 filesystem which lacks the appropriate amount of backup GDT entries to
support online-resizing.

Revert the 4K blocksize to 1K but keep the 256MB default size - this will
allow online resizing to a maximum of 256GB which should be sufficient
for now.

To support online resizing beyond 256GB we would need to enlarge the default
size to something like 2GB which would allow the FS to grow up to 2TB which
is the current theoretical LEDE limit due to the lack of GPT support on the
boot disk.

Signed-off-by: Jo-Philipp Wich <jo at mein.io>
 config/Config-images.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config/Config-images.in b/config/Config-images.in
index 7d38341..6dfb3d1 100644
--- a/config/Config-images.in
+++ b/config/Config-images.in
@@ -88,7 +88,7 @@ menu "Target Images"
 			prompt "Root filesystem block size"
 			depends on TARGET_ROOTFS_EXT4FS
 			  Select the block size of the root filesystem.

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