🔒 Fast ext4 fsck times, revisited | Unix & Linux Server

Fast ext4 fsck times, revisited

Veröffentlicht: 26.02.2009, 16:04 Uhr

Reagiere als Erste:r — dein Feedback zählt!

Last night I managed to finish up a rather satisfying improvement to ext4’s inode and block allocators. The ext4’s original allocator was actually a bit more simple-minded than ext3’s, in that it didn’t implement the Orlov algorithm to spread out top-level directories for better filesystem aging. It also was buggy in certain ways, where it would return ENOSPC even when there were still plenty of inodes in the file system.

So I had been working on extending ext3’s original Orlov allocator so it would work well with ext4. While I was at it, it occurred to me that one of the tricks I could play with ext4’s flex groups (which are higher-order collection of block groups), was to bias the block allocation algorithms such that the first block group in a flexgroup would be preferred for use by directories, and biased against data blocks for regular files. This meant that directory blocks would get clustered together, which cut a third off the time needed for e2fsck pass2:

  <td colspan="5" align="center">
    ext4 old allocator
  </td>
  
  <td rowspan="9" align="center">
  </td>
  
  <td colspan="5" align="center">
    ext4 new allocator
  </td>
</tr>

<tr>
  <td colspan="3" align="center">
    time (s)
  </td>
  
  <td colspan="2" align="center">
    I/O
  </td>
  
  <td colspan="3" align="center">
    time (s)
  </td>
  
  <td colspan="2" align="center">
    I/O
  </td>
</tr>

<tr>
  <td align="center" valign="middle">
    real
  </td>
  
  <td align="center" valign="middle">
    user
  </td>
  
  <td align="center" valign="middle">
    system
  </td>
  
  <td align="center" valign="middle">
    MB read
  </td>
  
  <td align="center" valign="middle">
    MB/s
  </td>
  
  <td align="center" valign="middle">
    real
  </td>
  
  <td align="center" valign="middle">
    user
  </td>
  
  <td align="center" valign="middle">
    system
  </td>
  
  <td align="center" valign="middle">
    MB read
  </td>
  
  <td align="center" valign="middle">
    MB/s
  </td>
</tr>

<tr>
  <td align="center">
    1
  </td>
  
  <td align="right">
    6.69
  </td>
  
  <td align="right">
    4.06
  </td>
  
  <td align="right">
    0.90
  </td>
  
  <td align="right">
    82
  </td>
  
  <td align="right">
    12.25
  </td>
  
  <td align="right">
    6.70
  </td>
  
  <td align="right">
    3.63
  </td>
  
  <td align="right">
    1.58
  </td>
  
  <td align="right">
    82
  </td>
  
  <td align="right">
    12.23
  </td>
</tr>

<tr>
  <td align="center">
    2
  </td>
  
  <td align="right">
    <b>13.34</b>
  </td>
  
  <td align="right">
    2.30
  </td>
  
  <td align="right">
    3.78
  </td>
  
  <td align="right">
    133
  </td>
  
  <td align="right">
    9.97
  </td>
  
  <td align="right">
    <b>4.24</b>
  </td>
  
  <td align="right">
    1.27
  </td>
  
  <td align="right">
    2.46
  </td>
  
  <td align="right">
    133
  </td>
  
  <td align="right">
    31.36
  </td>
</tr>

<tr>
  <td align="center">
    3
  </td>
  
  <td align="right">
    0.02
  </td>
  
  <td align="right">
    0.01
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
    1
  </td>
  
  <td align="right">
    63.85
  </td>
  
  <td align="right">
    0.01
  </td>
  
  <td align="right">
    0.01
  </td>
  
  <td align="right">
    0.01
  </td>
  
  <td align="right">
    1
  </td>
  
  <td align="right">
    82.69
  </td>
</tr>

<tr>
  <td align="center">
    4
  </td>
  
  <td align="right">
    0.28
  </td>
  
  <td align="right">
    0.27
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
    0.23
  </td>
  
  <td align="right">
    0.22
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
  </td>
  
  <td align="right">
  </td>
</tr>

<tr>
  <td align="center">
    5
  </td>
  
  <td align="right">
    2.60
  </td>
  
  <td align="right">
    2.31
  </td>
  
  <td align="right">
    0.03
  </td>
  
  <td align="right">
    1
  </td>
  
  <td align="right">
    0.38
  </td>
  
  <td align="right">
    2.42
  </td>
  
  <td align="right">
    2.15
  </td>
  
  <td align="right">
    0.07
  </td>
  
  <td align="right">
    1
  </td>
  
  <td align="right">
    0.41
  </td>
</tr>

<tr>
  <td align="center">
    Total
  </td>
  
  <td align="right">
    <b>23.06</b>
  </td>
  
  <td align="right">
    9.03
  </td>
  
  <td align="right">
    4.74
  </td>
  
  <td align="right">
    216
  </td>
  
  <td align="right">
    9.37
  </td>
  
  <td align="right">
    <b>13.78</b>
  </td>
  
  <td align="right">
    7.33
  </td>
  
  <td align="right">
    4.19
  </td>
  
  <td align="right">
    216
  </td>
  
  <td align="right">
    15.68
  </td>
</tr>

  <table border="1" cellspacing="1" cellpadding="2">
    <caption> Comparison of e2fsck times on an 32GB partition<br /> </caption> <colgroup align="center"> </colgroup> <colgroup align="right" span="3" width="50"> </colgroup> <colgroup align="right" span="2"> </colgroup> <colgroup> </colgroup> <colgroup align="right" span="3" width="50"> </colgroup> <colgroup align="right" span="2"> </colgroup> <colgroup> </colgroup> <tr>
      <td rowspan="3" align="center">
        Pass
      </td>
      
      <td colspan="5" align="center">
        ext3
      </td>
      
      <td rowspan="9" align="center">
      </td>
      
      <td colspan="5" align="center">
        ext4 old allocator
      </td>
    </tr>
    
    <tr>
      <td colspan="3" align="center">
        time (s)
      </td>
      
      <td colspan="2" align="center">
        I/O
      </td>
      
      <td colspan="3" align="center">
        time (s)
      </td>
      
      <td colspan="2" align="center">
        I/O
      </td>
    </tr>
    
    <tr>
      <td align="center" valign="middle">
        real
      </td>
      
      <td align="center" valign="middle">
        user
      </td>
      
      <td align="center" valign="middle">
        system
      </td>
      
      <td align="center" valign="middle">
        MB read
      </td>
      
      <td align="center" valign="middle">
        MB/s
      </td>
      
      <td align="center" valign="middle">
        real
      </td>
      
      <td align="center" valign="middle">
        user
      </td>
      
      <td align="center" valign="middle">
        system
      </td>
      
      <td align="center" valign="middle">
        MB read
      </td>
      
      <td align="center" valign="middle">
        MB/s
      </td>
    </tr>
    
    <tr>
      <td align="center">
        1
      </td>
      
      <td align="right">
        <b>108.40</b>
      </td>
      
      <td align="right">
        13.74
      </td>
      
      <td align="right">
        11.53
      </td>
      
      <td align="right">
        583
      </td>
      
      <td align="right">
        5.38
      </td>
      
      <td align="right">
        <b>6.69</b>
      </td>
      
      <td align="right">
        4.06
      </td>
      
      <td align="right">
        0.90
      </td>
      
      <td align="right">
        82
      </td>
      
      <td align="right">
        12.25
      </td>
    </tr>
    
    <tr>
      <td align="center">
        2
      </td>
      
      <td align="right">
        5.91
      </td>
      
      <td align="right">
        1.74
      </td>
      
      <td align="right">
        2.56
      </td>
      
      <td align="right">
        133
      </td>
      
      <td align="right">
        22.51
      </td>
      
      <td align="right">
        13.34
      </td>
      
      <td align="right">
        2.30
      </td>
      
      <td align="right">
        3.78
      </td>
      
      <td align="right">
        133
      </td>
      
      <td align="right">
        9.97
      </td>
    </tr>
    
    <tr>
      <td align="center">
        3
      </td>
      
      <td align="right">
        0.03
      </td>
      
      <td align="right">
        0.01
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
        1
      </td>
      
      <td align="right">
        31.21
      </td>
      
      <td align="right">
        0.02
      </td>
      
      <td align="right">
        0.01
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
        1
      </td>
      
      <td align="right">
        63.85
      </td>
    </tr>
    
    <tr>
      <td align="center">
        4
      </td>
      
      <td align="right">
        0.28
      </td>
      
      <td align="right">
        0.27
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
        0.28
      </td>
      
      <td align="right">
        0.27
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
      </td>
      
      <td align="right">
      </td>
    </tr>
    
    <tr>
      <td align="center">
        5
      </td>
      
      <td align="right">
        3.17
      </td>
      
      <td align="right">
        0.92
      </td>
      
      <td align="right">
        0.13
      </td>
      
      <td align="right">
        2
      </td>
      
      <td align="right">
        0.63
      </td>
      
      <td align="right">
        2.60
      </td>
      
      <td align="right">
        2.31
      </td>
      
      <td align="right">
        0.03
      </td>
      
      <td align="right">
        1
      </td>
      
      <td align="right">
        0.38
      </td>
    </tr>
    
    <tr>
      <td align="center">
        Total
      </td>
      
      <td align="right">
        <b>118.15</b>
      </td>
      
      <td align="right">
        16.75
      </td>
      
      <td align="right">
        14.25
      </td>
      
      <td align="right">
        718
      </td>
      
      <td align="right">
        6.08
      </td>
      
      <td align="right">
        <b>23.06</b>
      </td>
      
      <td align="right">
        9.03
      </td>
      
      <td align="right">
        4.74
      </td>
      
      <td align="right">
        216
      </td>
      
      <td align="right">
        9.37
      </td>
    </tr>
  </table>
  
  <p>
    </center>
  </p>
  
  <p>
  </p>
  
  <p>
    <center>
      </p> 
      
      <table border="1" cellspacing="1" cellpadding="2">
        <caption> Vital Statistics of the 32GB partition<br /> </caption> <colgroup align="right"> </colgroup> <colgroup align="left"></colgroup> <tr>
          <td align="right">
            312214
          </td>
          
          <td align="left">
            inodes used (14.89%)<br /> </tr> 
            
            <tr>
              <td align="right">
                263
              </td>
              
              <td align="left">
                non-contiguous files (0.1%)
              </td>
            </tr>
            
            <tr>
              <td align="right">
                198
              </td>
              
              <td align="left">
                non-contiguous directories (0.1%)
              </td>
            </tr>
            
            <tr>
              <td align="right">
                &nbsp;
              </td>
              
              <td align="left">
                # of inodes with ind/dind/tind blocks: 0/0/0
              </td>
            </tr>
            
            <tr>
              <td align="right">
                &nbsp;
              </td>
              
              <td align="left">
                Extent depth histogram: 292698/40
              </td>
            </tr>
            
            <tr>
              <td align="right">
                4388697
              </td>
              
              <td align="left">
                blocks used (52.32%)
              </td>
            </tr>
            
            <tr>
              <td align="right">
              </td>
              
              <td align="left">
                bad blocks
              </td>
            </tr>
            
            <tr>
              <td align="right">
                1
              </td>
              
              <td align="left">
                large file
              </td>
            </tr>
            
            <tr>
              <td align="right">
                &nbsp;
              </td>
              
              <td align="left">
                &nbsp;
              </td>
            </tr>
            
            <tr>
              <td align="right">
                263549
              </td>
              
              <td align="left">
                regular files
              </td>
            </tr>
            
            <tr>
              <td align="right">
                28022
              </td>
              
              <td align="left">
                directories
              </td>
            </tr>
            
            <tr>
              <td align="right">
                5
              </td>
              
              <td align="left">
                character device files
              </td>
            </tr>
            
            <tr>
              <td align="right">
                1
              </td>
              
              <td align="left">
                block device file
              </td>
            </tr>
            
            <tr>
              <td align="right">
                5
              </td>
              
              <td align="left">
                fifos
              </td>
            </tr>
            
            <tr>
              <td align="right">
                615
              </td>
              
              <td align="left">
                links
              </td>
            </tr>
            
            <tr>
              <td align="right">
                20618
              </td>
              
              <td align="left">
                symbolic links (19450 fast symbolic links)
              </td>
            </tr>
            
            <tr>
              <td align="right">
                5
              </td>
              
              <td align="left">
                sockets
              </td>
            </tr>
            
            <tr>
            </tr>
            
            <tr>
              <td align="right">
                312820
              </td>
              
              <td align="left">
                files
              </td>
            </tr></tbody> </table> 
            
            <p>
              </center>
            </p>

Auch interessante Nachrichten Fast ext4 fsck times, revisited

Thematisch verwandte Begriffe: Fast, ext4, fsck, times · 6 Treffer

IT Nachrichten ComputerBase

DLSS 5 auf Intel Arc: Neural Rendering wird zur Diashow

vor 12 Std. 📆 20.09.2026 um 08:26 Uhr

Weiterlesen ↗

Sichere Programmierung DEV Community

Your GDScript arrays are slower than you think — I built a CLI that detects the pitfalls and benchmarks them

vor 16 Std. 📆 20.09.2026 um 04:33 Uhr

Weiterlesen ↗

IT Security Downloads GitHub · openclaw/openclaw

GitHub Release: openclaw/openclaw vrelease-publish/91926f9b61a5-1789871489 (20.09.2026)

Release release-publish/91926f9b61a5-1789871489 von openclaw/openclaw auf GitHub: fix(release): repair 7.34 validation gates (#153190)

vor 16 Std. 📆 20.09.2026 um 00:26 Uhr

Weiterlesen ↗

Sichere Programmierung DEV Community

Qwen3.8-Flash-Next vs Qwen3.8-27B: 125B Parameters, 6B Active — What the Qwen4 Preview Changes

vor 15 Std. 📆 20.09.2026 um 05:44 Uhr

Weiterlesen ↗

Sichere Programmierung DEV Community

2 Pitfalls in Priority Probes: Letting One Real Request Through an Open Circuit Breaker

vor 18 Std. 📆 20.09.2026 um 02:00 Uhr

Weiterlesen ↗

Sicherheitslücken (CVE) KitPloit - PenTest Tools!

xalgorix v4.6.78

vor 21 Std. 📆 19.09.2026 um 21:27 Uhr

Weiterlesen ↗

Videos werden geladen ...

Beiträge werden geladen ...

Videos werden geladen ...

Beiträge werden geladen ...

Videos werden geladen ...

Beiträge werden geladen ...

Videos werden geladen ...

Beiträge werden geladen ...

Videos werden geladen ...

🚀 Auf tsecurity.de entdecken

tsecurity.de LIVE

Echtzeit-Radar & Feeds

👥 Community & Social

🕒 tsecurity.de Such-Trends & Chronologie

Fast ext4 fsck times, revisited

Auch interessante Nachrichten Fast ext4 fsck times, revisited

DLSS 5 auf Intel Arc: Neural Rendering wird zur Diashow

Your GDScript arrays are slower than you think — I built a CLI that detects the pitfalls and benchmarks them

GitHub Release: openclaw/openclaw vrelease-publish/91926f9b61a5-1789871489 (20.09.2026)

Qwen3.8-Flash-Next vs Qwen3.8-27B: 125B Parameters, 6B Active — What the Qwen4 Preview Changes

2 Pitfalls in Priority Probes: Letting One Real Request Through an Open Circuit Breaker

xalgorix v4.6.78

tsecurity.de App

tsecurity.de Live Threat Radar

Community-Puls — was gerade passiert

Aktivitäten deiner Analysten

Neues Thema oder Eilmeldung einreichen

Heiß diskutierte Einreichungen

🔖 Gespeicherte Artikel

tsecurity.de LIVE

Echtzeit-Radar & Feeds

👥 Community & Social

Fast ext4 fsck times, revisited

Mehr aus dieser Kategorie

Auch interessante Nachrichten Fast ext4 fsck times, revisited

DLSS 5 auf Intel Arc: Neural Rendering wird zur Diashow

Your GDScript arrays are slower than you think — I built a CLI that detects the pitfalls and benchmarks them

GitHub Release: openclaw/openclaw vrelease-publish/91926f9b61a5-1789871489 (20.09.2026)

Qwen3.8-Flash-Next vs Qwen3.8-27B: 125B Parameters, 6B Active — What the Qwen4 Preview Changes

2 Pitfalls in Priority Probes: Letting One Real Request Through an Open Circuit Breaker

xalgorix v4.6.78

tsecurity.de App

Themen-Radar & Intelligence Matrix

tsecurity.de Live Threat Radar

Community Radar & Live Chat

Community-Puls — was gerade passiert

Aktivitäten deiner Analysten

Neues Thema oder Eilmeldung einreichen

Heiß diskutierte Einreichungen Aktualisieren

🔖 Gespeicherte Artikel

Heiß diskutierte Einreichungen