Backup failed ERR_CHILD_PROCESS_STDIO_MAXBUFFER

[balticpenguin]

Hi,

my last backup failed with

saveFsMetadata errored with code ERR_CHILD_PROCESS_STDIO_MAXBUFFER message stdout maxBuffer length exceeded

I tried it again, but it crashes and I still get this error.
Can anyone tell me what is going wrong and how I can fix it?

[nebulon]

I guess one of these buffer settings are not enough in your case: https://git.cloudron.io/cloudron/box/-/blob/master/src/backupformat/rsync.js?ref_type=heads#L113

You could adjust them manually on your server via SSH, carefully and run systemctl restart box then try another backup.

[girish]

Which version of Cloudron are you on? We already bumped the buffer size to 80MB which should be pretty big. Do you think you have a lot of files?

[balticpenguin]

We have version v7.7.2.

Most of the files are probably located within Nextcloud. I counted up the user directories once: We have around 165000 files under /app/data/<user>/files/ with a size of 160GB.

How can I change the buffer size? Is there a command or do I have to change something directly in a file?

[girish]

@balticpenguin yes, correct. Can you edit /home/yellowtent/box/src/backupformat/rsync.js directly ? Change https://git.cloudron.io/cloudron/box/-/blob/master/src/backupformat/rsync.js?ref_type=heads#L113 to 1024 * 1024 * 120 (120MB buffer size) . There is another size couple of lines below. Change that too. You don't need to restart anything for the changes to take effect. Try another backup and let us know if that worked and we will fix the code accordingly.

[balticpenguin]

@girish same problem as before

[girish]

@balticpenguin ok not sure, what is going on then. Are you able to write to us at support@cloudron.io and we have to debug on the server. Thanks!

[girish]

The issue here had to do with something in JupyterHub container creating a massive number of folders recursively. Think 300k folders or something. Nuking all that stuff, made backups work again.