Servicing log tip

This section gives information about servicing log.

Re-creating NVRAM disks for IBM Storage Scale System 5000
The Non-Volatile Random-Access Memory (NVRAM) is supported by NVDIMM block devices that are installed on each of the I/O nodes. The NVRAM pdisks are created from NVDIMM block devices that are installed on the Enterprise Storage Server® I/O nodes to hold data for the log tip pdisks. There are two NVDIMM block drives, /dev/pmem0s and /dev/pmem1s, available on each of the IBM Storage Scale System I/O nodes. NVRAM pdisks are used to store the log tip data, which is eventually moved to the log home vdisk. Although IBM Storage Scale System can continue to function without NVRAM pdisks, the performance is impacted without their presence. Therefore, it is important to ensure that the NVRAM pdisks are functioning always.
Replacing the logtip backup solid state drive
The solid state drive (SSD) is used to hold the logtip backup vdisk. In a normal operation, when both the copies of the primary logtip vdisk on the NVDIMM are available, the logtip backup vdisk is not used during the write. However, when a write to the logtip is not able to make copies on every replica of the vdisk, GNR also writes the logtip data to the logtip backup vdisk.

Parent topic: IBM Storage Scale System Problem Determination Guide