+README/"Linux kernel flaw" and its handling (last sector failed reads)

[badblock-guess.git] / README

diff --git a/README b/README
index fee9795..b02fc61 100644 (file)
--- a/README
+++ b/README
@@ -91,6 +91,21 @@ performance about 90KB/s (approx. 7.5GB/24hours if no badblocks read retrying
 is needed). YMMV.
 
 
+Linux kernel flaw
+-----------------
+
+Linux kernels have internal blocksize 1KB but the partitions can be sized by
+512 sectors and thus the last odd partition sector gets inaccessible.
+This isn't a problem for a the disk devices as AFAIK all the disks have always
+even number of sectors.
+
+This program is aware of this flaw and it will not report last such sector as
+BAD - just the appropriate warning is supplied (to stderr). This may be visible
+for example while recovering NTFS partition with odd cylinder number (=>odd
+sector count) as NTFS uses the last partition sector for its superblock backup.
+Fortunately CHKDSK will fix it back, of course.
+
+
 Compilation
 -----------