Managing operation of a data storage system with reservation of metadata space

A computer program product comprising a non-transitory computer-readable storage medium storing a set of instructions, which, when performed by processing circuitry of a data storage apparatus (DSA), causes the processing circuitry to manage operation of the DSA by:

• reserving space within a dedicated metadata storage region (DMSR);
• in response to determining that accommodating a storage request requires use of the reserved space, entering a restricted write mode, wherein determining that accommodating the storage request requires use of the reserved space includes:
• calculating a remaining amount, R, of space in the DMSR;
• determining an amount, N, of new metadata needed to accommodate the storage request;
• and
• given a size, P, of the reserved space, determining that R−N<P;
• while operating in the restricted write mode, using the reserved space in a process that frees space within the DMSR outside the reserved space;
• and
• exiting the restricted write mode in response to freeing space within the DMSR outside the reserved space.

A data storage apparatus (DSA) comprising:

• a plurality of non-transitory persistent storage drives;
• and
• processing circuitry coupled to memory configured to manage operation of the DSA by:
• reserving space within a dedicated metadata storage region (DMSR);
• in response to determining that accommodating a storage request requires use of the reserved space, entering a restricted write mode, wherein determining that accommodating the storage request requires use of the reserved space includes:
• calculating a remaining amount, R, of space in the DMSR;
• determining an amount, N, of new metadata needed to accommodate the storage request;
• and
• given a size, P, of the reserved space, determining that R−N<P;
• while operating in the restricted write mode, using the reserved space in a process that frees space within the DMSR outside the reserved space;
• and
• exiting the restricted write mode in response to freeing space within the DMSR outside the reserved space.