Hi, With e2fsck -b option, we can use an alternative superblock instead of the normal superblock. However it shows some warnings, especially checksum warnings appear when we do e2fsck -b every time. Test environment: - kernel 3.1.0-rc3 - e2fsprogs (commit:d4c0d8e5b858cdf3d3000f2b3fca532787f34a02) # mkfs -t ext4 /dev/sda8 # e2fsck -b 32768 /dev/sda8 e2fsck 1.42-WIP (02-Jul-2011) One or more block group descriptor checksums are invalid. Fix<y>? yes Group descriptor 0 checksum is invalid. FIXED. Group descriptor 1 checksum is invalid. FIXED. Group descriptor 2 checksum is invalid. FIXED. Group descriptor 3 checksum is invalid. FIXED. Group descriptor 4 checksum is invalid. FIXED. Group descriptor 5 checksum is invalid. FIXED. Group descriptor 6 checksum is invalid. FIXED. Group descriptor 7 checksum is invalid. FIXED. Group descriptor 8 checksum is invalid. FIXED. Group descriptor 9 checksum is invalid. FIXED. Group descriptor 10 checksum is invalid. FIXED. Group descriptor 11 checksum is invalid. FIXED. Group descriptor 12 checksum is invalid. FIXED. Group descriptor 13 checksum is invalid. FIXED. Group descriptor 14 checksum is invalid. FIXED. Group descriptor 15 checksum is invalid. FIXED. Group descriptor 16 checksum is invalid. FIXED. Group descriptor 17 checksum is invalid. FIXED. Group descriptor 18 checksum is invalid. FIXED. Group descriptor 19 checksum is invalid. FIXED. Group descriptor 20 checksum is invalid. FIXED. Group descriptor 21 checksum is invalid. FIXED. Group descriptor 22 checksum is invalid. FIXED. Group descriptor 23 checksum is invalid. FIXED. Group descriptor 24 checksum is invalid. FIXED. Group descriptor 25 checksum is invalid. FIXED. Group descriptor 26 checksum is invalid. FIXED. Group descriptor 27 checksum is invalid. FIXED. Group descriptor 28 checksum is invalid. FIXED. Group descriptor 29 checksum is invalid. FIXED. Group descriptor 30 checksum is invalid. FIXED. Group descriptor 31 checksum is invalid. FIXED. /dev/sda8 contains a file system with errors, check forced. Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information Block bitmap differences: -(65600--65602) -(65611--65612) -(65621--65622) -(65625--65627) -65630 -(65632--65634) -(65643--65644) -(65653--65654) -(65657--65659) -65662 -(65664--65666) -(65675--65676) -(65685--65686) -(65689--65691) -65694 -67584 -(67586--67587) -(67589--67592) -67598 -67628 -(67648--67650) -(67659--67660) -(67669--67670) -(67673--67675) -67678 -(67680--67682) -(67691--67692) -(67701--67702) -(67705--67707) -67710 -(67712--67714) -(67723--67724) -(67733--67734) -(67737--67739) -67742 -(67792--67793) -67811 -(67904--67905) -(67912--67913) -(68610--68612) -(68736--68738) -(68747--68748) -(68757--68758) -(68761--68763) -68766 -(77831--77832) -77839 -(77870--77871) -77878 -(77888--77890) -(77899--77900) -(77909--77910) -(77913--77915) -77918 -(77920--77922) -(77931--77932) -(77941--77942) -(77945--77947) -77950 -(77952--77954) -(77963--77964) -(77973--77974) -(77977--77979) -77982 -78032 -78051 -(78054--78061) -78563 -(78568--78569) -78688 -(78850--78852) -(78976--78978) -(78987--78988) -(78997--78998) -(79001--79003) -79006 -(79879--79880) -79887 -79931 -(79936--79938) -(79947--79948) -(79957--79958) -(79961--79963) -79966 -(79968--79970) -(79979--79980) -(79989--79990) -(79993--79995) -79998 -(80000--80002) -(80011--80012) -(80021--80022) -(80025--80027) -80030 -80080 -80099 -80104 -80114 -80193 -80201 -(80207--80210) -(80224--80225) -80233 -(80239--80242) -80258 -80265 -(80271--80274) -80288 -80290 -80297 -(80303--80306) -(80321--80322) -80329 -(80335--80338) -(80352--80354) -80361 -(80367--80370) -80387 -80393 -(80399--80402) -80416 -80419 -80425 -(80431--80434) -80449 -80451 -80457 -(80463--80466) -(80480--80481) -80483 -80489 -(80495--80498) -(80514--80515) -80521 -(80527--80530) -80544 -(80546--80547) -80553 -(80559--80562) -(80577--80579) -80585 -(80591--80594) -(80608--80611) -(80617--80618) -(80623--80626) -(80898--80900) -(81024--81026) -(81035--81036) -(81045--81046) -(81049--81051) -81054 -(86022--86024) -86030 -86062 -(86080--86082) -(86091--86092) -(86101--86102) -(86105--86107) -86110 -(86112--86114) -(86123--86124) -(86133--86134) -(86137--86139) -86142 -(86144--86146) -(86155--86156) -(86165--86166) -(86169--86171) -86174 -86225 -86245 -86338 -(86344--86345) -86368 -86370 -(86376--86377) -(86401--86402) -(86408--86409) -(86432--86434) -(86440--86441) -(87042--87044) -(87168--87170) -(87179--87180) -(87189--87190) -(87193--87195) -87198 -(565248--589823) Fix<y>? yes /dev/sda8: ***** FILE SYSTEM WAS MODIFIED ***** /dev/sda8: 11/262144 files (0.0% non-contiguous), 51278/1048576 blocks Regards, Akira Fujita -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
