ERROR : No more available loop devices, try increasing 'max loop devices' in singularity.con

[sangfengchn]

Hi,
I have some trouble as same as the title when I try to run an image, and try to find salvation by Google, Bing, and Baidu and failed. Have you ever encountered the same problem? If so, how did you solve it?

• singularity version, 2.6.1-dist
• OS version: Ubuntu 20.04.2 LTS in Windows 10 WSL
• pull image: singularity pull --name hello.simg shub://vsoch/hello-world
• run image: singularity shell hello.simg

Thanks so much.

[a-ludi]

I recently encountered the same problem with Singularity 3.7.3 on Arch linux. It used to work for me but no fails with

FATAL:   container creation failed: mount /proc/self/fd/3->/var/singularity/mnt/session/rootfs error: while mounting image /proc/self/fd/3: failed to find loop device: could not attach image file to loop device: no loop devices available

There are certainly enough loop devices available:

$ ls /dev/loop*
/dev/loop0    /dev/loop121  /dev/loop145  /dev/loop169  /dev/loop192  /dev/loop215  /dev/loop239  /dev/loop32  /dev/loop56  /dev/loop8
/dev/loop1    /dev/loop122  /dev/loop146  /dev/loop17   /dev/loop193  /dev/loop216  /dev/loop24   /dev/loop33  /dev/loop57  /dev/loop80
/dev/loop10   /dev/loop123  /dev/loop147  /dev/loop170  /dev/loop194  /dev/loop217  /dev/loop240  /dev/loop34  /dev/loop58  /dev/loop81
/dev/loop100  /dev/loop124  /dev/loop148  /dev/loop171  /dev/loop195  /dev/loop218  /dev/loop241  /dev/loop35  /dev/loop59  /dev/loop82
/dev/loop101  /dev/loop125  /dev/loop149  /dev/loop172  /dev/loop196  /dev/loop219  /dev/loop242  /dev/loop36  /dev/loop6   /dev/loop83
/dev/loop102  /dev/loop126  /dev/loop15   /dev/loop173  /dev/loop197  /dev/loop22   /dev/loop243  /dev/loop37  /dev/loop60  /dev/loop84
/dev/loop103  /dev/loop127  /dev/loop150  /dev/loop174  /dev/loop198  /dev/loop220  /dev/loop244  /dev/loop38  /dev/loop61  /dev/loop85
/dev/loop104  /dev/loop128  /dev/loop151  /dev/loop175  /dev/loop199  /dev/loop221  /dev/loop245  /dev/loop39  /dev/loop62  /dev/loop86
/dev/loop105  /dev/loop129  /dev/loop152  /dev/loop176  /dev/loop2    /dev/loop222  /dev/loop246  /dev/loop4   /dev/loop63  /dev/loop87
/dev/loop106  /dev/loop13   /dev/loop153  /dev/loop177  /dev/loop20   /dev/loop223  /dev/loop247  /dev/loop40  /dev/loop64  /dev/loop88
/dev/loop107  /dev/loop130  /dev/loop154  /dev/loop178  /dev/loop200  /dev/loop224  /dev/loop248  /dev/loop41  /dev/loop65  /dev/loop89
/dev/loop108  /dev/loop131  /dev/loop155  /dev/loop179  /dev/loop201  /dev/loop225  /dev/loop249  /dev/loop42  /dev/loop66  /dev/loop9
/dev/loop109  /dev/loop132  /dev/loop156  /dev/loop18   /dev/loop202  /dev/loop226  /dev/loop25   /dev/loop43  /dev/loop67  /dev/loop90
/dev/loop11   /dev/loop133  /dev/loop157  /dev/loop180  /dev/loop203  /dev/loop227  /dev/loop250  /dev/loop44  /dev/loop68  /dev/loop91
/dev/loop110  /dev/loop134  /dev/loop158  /dev/loop181  /dev/loop204  /dev/loop228  /dev/loop251  /dev/loop45  /dev/loop69  /dev/loop92
/dev/loop111  /dev/loop135  /dev/loop159  /dev/loop182  /dev/loop205  /dev/loop229  /dev/loop252  /dev/loop46  /dev/loop7   /dev/loop93
/dev/loop112  /dev/loop136  /dev/loop16   /dev/loop183  /dev/loop206  /dev/loop23   /dev/loop253  /dev/loop47  /dev/loop70  /dev/loop94
/dev/loop113  /dev/loop137  /dev/loop160  /dev/loop184  /dev/loop207  /dev/loop230  /dev/loop254  /dev/loop48  /dev/loop71  /dev/loop95
/dev/loop114  /dev/loop138  /dev/loop161  /dev/loop185  /dev/loop208  /dev/loop231  /dev/loop255  /dev/loop49  /dev/loop72  /dev/loop96
/dev/loop115  /dev/loop139  /dev/loop162  /dev/loop186  /dev/loop209  /dev/loop232  /dev/loop26   /dev/loop5   /dev/loop73  /dev/loop97
/dev/loop116  /dev/loop14   /dev/loop163  /dev/loop187  /dev/loop21   /dev/loop233  /dev/loop27   /dev/loop50  /dev/loop74  /dev/loop98
/dev/loop117  /dev/loop140  /dev/loop164  /dev/loop188  /dev/loop210  /dev/loop234  /dev/loop28   /dev/loop51  /dev/loop75  /dev/loop99
/dev/loop118  /dev/loop141  /dev/loop165  /dev/loop189  /dev/loop211  /dev/loop235  /dev/loop29   /dev/loop52  /dev/loop76  /dev/loop-control
/dev/loop119  /dev/loop142  /dev/loop166  /dev/loop19   /dev/loop212  /dev/loop236  /dev/loop3    /dev/loop53  /dev/loop77
/dev/loop12   /dev/loop143  /dev/loop167  /dev/loop190  /dev/loop213  /dev/loop237  /dev/loop30   /dev/loop54  /dev/loop78
/dev/loop120  /dev/loop144  /dev/loop168  /dev/loop191  /dev/loop214  /dev/loop238  /dev/loop31   /dev/loop55  /dev/loop79
$ mount | grep loop
(empty output)

[a-ludi]

Oh, not forget I am not running any other singularity processes and the configuration is just fine as well:

# MAX LOOP DEVICES: [INT]
# DEFAULT: 256
# Set the maximum number of loop devices that Singularity should ever attempt
# to utilize.
max loop devices = 256

[sangfengchn]

Thank you so much. The problem is solved by adding the option "--sandbox" when building an image. Maybe you can try it, too.

[dtrudg]

@sangfengchn please note that Singularity 2.x is no longer supported. If you have the issue with the latest SingularityCE release we can look into it, but I will close this report for 2.x

@a-ludi - please could you open this in a separate issue as given you see the problem here on 3.x. It would be useful to see the debug output from singularity -d ... and the output of mountinfo when this occurs. Thank you.