eva leveling and sparing

[ilayy]

hi experts
i need your help i am soo confused about leveling and sparing
sparing is the reconstruction of data using the raid.
leveling is redistribution of data across all disks in disk group.
my question is
1)the protection level is used for sparing only or also to make the leveling
2)if i have an occupancy level of 98% but i have no disk failure just i want to add disks leveling can occur with no problem? if no for what i need free space for redistributing data?

[Uwe Zessin]

'sparing' is not the 'reconstruction' of data...

The "protection level" defines the amount of spaced reserved in the disk group to be able to reconstruct data after a disk drive has failed. Think of it as a set of "virtualized spare disks".

It is important to understand that the "protection level" does NOT provide any data redundancy. That is only done by the VRAID-level (1,5,6) of a virtual disk.

You can create a virtual disk with VRAID-0, define the "protection level" to 'double', but you WILL lose data when a disk drive in that disk group fails.


According to some best practices paper, the EVA should be able to do leveling as long as at least 5 GigaBytes are free in a disk group.