Changing number of fs groups

Site Administrators
1

Is there an easy way to change the number of fs groups in use in an EOS instance? I’d like to limit the possibility of both file replicas being inaccessible in the event of a hardware failure. We have some FST nodes where 2 nodes share a disk storage device and each node sees 3 filesystems. We currently have 4 groups and unless I move to 6, there will be cases where a disk storage device will have filesystems in (for example) 0, 1, 2, 3, 0, 1. So if we lose the device there will almost certainly be cases where both replicas are on that device. If I move to 6 groups, this can be avoided.

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Dan Szkola
FNAL

2

Hi Dan,

You can modify the number of allowed groups in a space by using the following command:
eos space define <space_name> <grp_sz> <grp_mod>
Then you will need to create new file systems and add then to the newly available empty groups.

Cheers,
Elvin