2
votes
3answers
77 views

How to repair a file system corruption?

Debian on external USB SSD drive. There was some error in dmesg log file: ...[ 3.320718] EXT4-fs (sdb2): INFO: recovery required on readonly filesystem [ 3.320721] EXT4-fs (sdb2): write access ...
0
votes
0answers
24 views

Could I disable ext4's journaling safely in BBWC?

I knew set "nobarrier" flag is safe in BBWC when using ext4,but since "nobarrier" flag couldn't ensure proper order of journal logging and data flushing,then it seems journaling is useless。So is it ...
1
vote
0answers
51 views

What does the 'barrier' mount flag mean in Linux?

The manual for the 'barrier' mount option is: barrier=0 / barrier=1 This disables / enables the use of write barriers in the jbd code.barrier=0 disables, barrier=1 enables (default). ...
1
vote
1answer
38 views

Could I set flag “barrier=0” when using SSD?

I'm using ext4 filesystem in SSD,when mounting SSD,could I use flag "barrier=0"? I knew this flag is safe for BBU(battery backup unit),but is it safe for SSD?
6
votes
2answers
818 views

“Converting” a filesystem from ext3 to ext4

I've read on some Q&A on this website that one can "convert" an ext3 filesystem to ext4 without formatting, by issuing tune2fs -O extents,uninit_bg,dir_index /dev/dev-name And then running ...
5
votes
3answers
187 views

What filesystem metadata operations are actually journaled in ext4 & xfs?

I can't find a simple, straight answer about which filesystem metadata operations are actually persisted to the ext4 & xfs filesystem journals. Note that I am not inquiring about what POSIX ...
1
vote
1answer
176 views

Best parameters for ext4 filesystem to handle virtualbox disk images

I have ext4 partition, which holds disk image files VirtualBox works with. They all are fixed-size images (i.e. files never change their size). They are defragmented as much as possible (with ...
3
votes
1answer
82 views

ext4, why 70k file takes 88 blocks

[root@xx]# cat -n create_extents.sh 1 #!/bin/bash 2 3 if [ $# -ne 2 ] 4 then 5 echo "$0 [filename] [size in kb]" 6 exit 1 7 fi 8 9 ...
1
vote
4answers
53 views

targeting a specific block with e2fsck to shorten wait

Recently had a LVM'd CentOS 6.5 install get accidentally cold-shutdown. On bootup, it says that the home partition need fscking: /dev/mapper/vg_myserver-lv_home: Block bitmap for group 3072 is not ...
0
votes
1answer
108 views

Recovering truncated file

I'm in a peculiar situation. While editing a Perl program I accidentally truncated the file to zero length (using an Emacs lisp code I was developing). I need to recover that program... How do I that ...
0
votes
1answer
58 views

mke2fs difference between -i and -I options

sudo mke2fs Usage: mke2fs [-c|-l filename] [-b block-size] [-C cluster-size] [-i bytes-per-inode] [-I inode-size] [-J journal-options] [-G flex-group-size] [-N number-of-inodes] [-m ...
3
votes
1answer
130 views

Something like VMware “Changed Block Tracking” (CBT) in linux

I'm wondering if is there any possibility to track changed blocks in linux with an ext3/ext4 filesystem (or a specific one supporting it). I mean a feture like the Changed Block Tracking (CBT) ...
3
votes
1answer
534 views

“unknown partition table” - misconfigured kernel

I was compiling a custom linux kernel for a newly installed machine, and after booting into the new kernel (3.12), the init process fails to find a root device, which I traced to the system getting an ...
1
vote
1answer
55 views

Restored VG has shifted volumes

I'm recovering a PV on a mdadm RAID 1 with a single VG containing several LVs. The underlying devices have several bad sectors (one just a few, the other really much) and a silly typo made it ...
2
votes
1answer
87 views

relocate ext4 structures to survive truncation

I have a 6Gb raw disk image with 1 ext4 partition on it. I have only 1Gb worth of data on it Is there a way to reposition/adjust ext4 datastructures such that I can truncate the disk at 1 GB or 1.2Gb ...
1
vote
1answer
112 views

How does my partition (ext4) know its size of used/free space?

I ran df, and the output appears almost instantly: (FS Size Used Avail Use%) /dev/sda1 145G 8.4G 130G 7% sda1 is an ext4 partition. Without summing the size of all files, how can ...
1
vote
1answer
286 views

Linux EXT 4: How to list files that occupy a block group?

Linux EXT 4: How to list files that occupy a block group? I believe a file can span multiple block groups. Given a block group, how do i enumerate the paths of all files contained in it?
6
votes
4answers
329 views

Are short-lived files flushed to disk?

My program creates many small short-lived files. They are typically deleted within a second after creation. The files are in an ext4 file system backed by a real hard disk. I know that Linux ...
3
votes
3answers
2k views

How to determine how many files are within a directory without counting?

I've been having a fairly serious issue on a high traffic web server. PHP pages are slowing down considerably, and it only seems to be an issue on pages where sessions are accessed, or a certain table ...
1
vote
0answers
122 views

Disk partition emptied during tar backup

This morning I was doing a routine backup of my development drive, one of 4 primary partitions on my hard-drive. The script I ran was: filename="/home/Backups/Devi_"`eval date +%Y%m%d`".tgz" touch ...
0
votes
2answers
284 views

Recover Linux ext4 partition formatted to hfs+

I have a Linux partition formatted to ext4 and I accidentally formatted it with Mac OS X Disk Utility to HFS+ (Mac OS X Extended Journaled). I tried to recover it with http://www.r-studio.com/ on ...
3
votes
1answer
521 views

Risks involved with lazy_itable_init=1 for ext4 fs on SD card

My setup is the following: Linux kernel 2.6.28 e2fsprogs 1.42.7 64 GB class 10 SD card I am attempting to speed up the time it takes to format the entire card to an ext4 filesystem. My research ...
8
votes
1answer
5k views

How can I mount filesystems with > 4KB block sizes?

I have a 3TB hard disk pulled out of a WD Mybook Live NAS. The partition table is as follows: Model: ATA WDC WD30EZRS-11J (scsi) Disk /dev/sdb: 3001GB Sector size (logical/physical): 512B/4096B ...
14
votes
2answers
2k views

Can the same ext4 disk be mounted from two hosts, one readonly?

I know that mounting the same disk with an ext4 filesystem from two different servers (it's an iSCSI vloume) will likely corrupt data on the disk. My question is will it make any difference if one of ...
5
votes
2answers
6k views

Should a laptop user switch from ext4 to btrfs?

Related to this. I'd like to take advantage of an OS switch to upgrade to BTRFS. BTRFS claims to offer a lot (data-loss resiliency, self-healing if RAID, checksumming of metadata and data, ...
32
votes
6answers
19k views

How do I know if a partition is ext2, ext3, or ext4?

I just formatted stuff. One disk I format as ext2. The other I want to format as ext4. I want to test how they perform. Now, how do I know the kind of file system in a partition?
5
votes
1answer
571 views

What are EXT4 Security Labels?

During Gentoo installation of Gnome keyring, I am told to switch on EXT4 Security Labels, which is described in the kernel documentation by: Security labels support alternative access control ...
1
vote
1answer
82 views

What is a generic way of finding out whether the kernel has ext4 (or other) bugs?

From /. found this worrisome post by Theodore Ts'o. Turns out ext4 has some journalling problems. How can I quickly find out version numbers of susceptible kernels for this and other bugs?
0
votes
0answers
37 views

Recreating EXT4 partition without losing data [duplicate]

Possible Duplicate: Can't mount EXT4 hard drive after mounting it in windows I have a 2TB Western External USB harddisk. I formatted it to EXT4. one time I plugged it to a windows ...
10
votes
2answers
5k views

Is it possible to change Inode count on an ext4 filesystem? [duplicate]

Possible Duplicate: How can I increase the number of inodes in an ext4 filesystem? I have a homemade NAS with Debian Wheezy 64bit. It has three disks - 2x2TB and 1.5TB, pooled together ...
4
votes
1answer
140 views

ext4 directory lists as a file

I'm working with a large (8TB) EXT4 filesystem in linux. After a power outage, the filesystem wouldn't mount. fsck is taking weeks to complete, but i ran testdisk and i'm able to see my partition ...
5
votes
1answer
4k views

Find which files are affected by bad blocks on ext4 filesystem

I have an ext4 filesystem that recently developed some bad sectors. Running fsck.ext4 -c finds and remembers the bad blocks. How can I find which files (if any) included these bad blocks so I can ...
3
votes
2answers
1k views

ext4 used space (not -m option, not deleted files)

I'm a bit puzzled about the way ext4 reports used space. On a new Debian wheezy (testing) installation, I consistently got about 1GB extra space used with a 60GB SSD, when compared to du. I then ...
5
votes
2answers
4k views

Why is (free_space + used_space) != total_size in df? [duplicate]

Possible Duplicate: ext4: How to account for the filesystem space? I have a ~2TB ext4 USB external disk which is about half full: $ df Filesystem 1K-blocks Used Available ...
10
votes
1answer
4k views

What does fsck -p (preen) do on ext4?

I was reading a blog post about filesystem repair and the author posted a good question… fsck -p is supposed to fix minor errors automatically without human intervention. But what exactly will it fix ...
7
votes
6answers
3k views

Sync writes very slow. Ubuntu 10.10, 32 bits, ext4

I am running ActiveMQ on my Macbook Pro that runs Ubuntu 10.10, 32 bits with an ext4 partition. Linux iker-laptop 2.6.35-23-generic-pae #40-Ubuntu SMP Wed Nov 17 22:32:51 UTC 2010 i686 GNU/Linux If ...