Why Use SANs?
Originally written by
- In the past - each server had its own internal disks - hard to replace
them or add more.
- Disks were moved outside (up to 7 disks per SCSI controller) - requires
down-time for adding disks, many small disks for many servers cost a lot.
- Disks were moved to NAS servers (that expose CIFS or NFS shares) - not
enough control by the applications (e.g. what if i want raw device access?,
how does it scale to many servers and lots of TB of data? also, Ethernet
performance is limiting)
- Disks were moved to RAIDs that expose block-devices directly, across
a fiber-channel network.