https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-5127 Lustre <p>We have an OST that is not mountable because a superblock is unreadable from the backend storage. In order to begin repairs, we need to run mke2fs to get the alternate superblocks to then run debugfs. Unfortunately, the current version of e2fsprogs does not handle this by default. Can you advise the correct options to use with mke2fs with -n (very important!). If we run with -O64bit without any other of the original filesystem options, will that do it?</p> <p><span class="error">&#91;root@f1-oss1d5 share&#93;</span># /tmp/e2fsprogs-new/sbin/mke2fs -n /dev/mapper/f1-ddn1d-l30<br/> mke2fs 1.42.9.wc1 (24-Feb-2014)<br/> mke2fs: Size of device (0x151e00000 blocks) /dev/mapper/f1-ddn1d-l30 too big to be expressed<br/> in 32 bits using a blocksize of 4096.</p> <p><span class="error">&#91;root@f1-oss1d5 man8&#93;</span># dumpe2fs /dev/mapper/f1-ddn1d-l30 | grep superblock<br/> dumpe2fs 1.42.7.wc2 (07-Nov-2013)<br/> dumpe2fs: Attempt to read block from filesystem resulted in short read while trying to open /dev/mapper/f1-ddn1d-l30<br/> Couldn't find valid filesystem superblock.<br/> <span class="error">&#91;root@f1-oss1d5 man8&#93;</span># </p> RHEL 6.4<br/> e2fsprogs 1.42.9.wc1 LU-5127

Running mke2fs to get alternate superblocks on >16TB LUN

Question/Request Critical Closed Fixed Jian Yu Blake Caldwell Sat, 31 May 2014 17:06:49 +0000 Tue, 3 Jun 2014 15:01:38 +0000 Tue, 3 Jun 2014 15:00:48 +0000 Lustre 2.4.1 0 5 <p>Yu, Jian</p> <p>Could you please advise here?</p> <p>Thanks</p> <p>Peter</p> <p>Hello,</p> <p>We were able to resolve this issue. The -t ext4 option was critical to get mke2fs to assume the 64bit feature. Here are the full commands that we used.</p> <p><span class="error">&#91;root@f1-oss1d1 ~&#93;</span># mke2fs -n -t ext4 -O has_journal,ext_attr,resize_inode,dir_index,filetype,extent,64bit,mmp,flex_bg,sparse_super,large_file,huge_file,uninit_bg,dir_nlink,quota /dev/mapper/f1-ddn1d-l30<br/> mke2fs 1.42.7.wc2 (07-Nov-2013)<br/> Filesystem label=<br/> OS type: Linux<br/> Block size=4096 (log=2)<br/> Fragment size=4096 (log=2)<br/> Stride=256 blocks, Stripe width=256 blocks<br/> 354287616 inodes, 5668601856 blocks<br/> 283430092 blocks (5.00%) reserved for the super user<br/> First data block=0<br/> Maximum filesystem blocks=7816085504<br/> 172992 block groups<br/> 32768 blocks per group, 32768 fragments per group<br/> 2048 inodes per group<br/> Superblock backups stored on blocks:<br/> 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,<br/> 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,<br/> 102400000, 214990848, 512000000, 550731776, 644972544, 1934917632,<br/> 2560000000, 3855122432</p> <p><span class="error">&#91;root@f1-oss1d1 ~&#93;</span># debugfs -b 4096 -s 32768 -c -R 'icheck 3992983288' /dev/mapper/f1-ddn1d-l30</p> <p>Hi Blake,</p> <p>For -O option, you can only specify the features which are not listed in the [defaults] section and [fs_types] subsectionin in the /etc/mke2fs.conf configuration file.</p> <p>Is there anything else I can help in this ticket?</p> <p>That answers it. Thanks!</p> <p>You're welcome, Blake. May I close this ticket?</p> <p>Yes. Please do.</p> Development Rank 1|hzwnhz: Rank (Obsolete) 14152