I am currently kind of having trouble to understand between NAS and SAN.
As far as I figured out, NAS and SAN are kind of defined as below.
NAS(Network attached storage)
- Usually used as file storage and use Ethernet Infrastructure to communicate
- As file storage, support protocols like NFS, CIFS, SMB, HTTP(S)
SAN(Storage Area Network)
- Network Protocol to communicate with block storage for data access.
- Configured with separated network system
- Commonly based on Fibre Channel(FC) technology.
- Could use iSCSI(in small and medium sized business) or FCoE for less expensive alternative to FC
So, below is my questions.
1. Is File Storage and Block Storage are the solutions? I researched and found that NAS is File Storage Solution and SAN Storage is Block Storage Solution.
- In that case, are their base infrastructure(storage device) same? Only different with protocols, network devices, may be storage os something that controls underline device and way of usage?
2. I found there are NAS Solutions that support iSCSI. But I found that iSCSI is SCSI Protocol that use TCP/IP Network system and SCSI is for block level storage communication protocols.
- And Now I am confused. NAS is a file storage solution and how could that support iSCSI Protocol?
3. Are AWS root disk and EBS storage SAN Storage?
- I read that SAN Storage configuration could be expensive so iSCSI or FCoE are less expensive way to configure.
- With what technology AWS storage Infrastructure is configured??
I am kind of newly studying of these storage part computer science and got some questions.
Is there anyone can explain those questions clearly?
Thank you.
It depends on what you call a "Solution". The basic infrastructure is the same it's a some kind of a "storage server" (storage system) with physical disk(s), but it very much dependent of technologies, vendors and various options. Typically, a storage system provides access to its physical disks with different protocols of 2 main groups: block-level protocols like SCSI or rarely ATA on one hand, or file-level protocols like NFS, CIFS, etc on the other. It doesn't mean, a storage system can't work in both, block and file modes.
Storage network - SAN can be build over FC, FCoE, converged infrastructure, pure TCP/IP for iSCSI, Infiniband or any other infrastructure. Typically, when people say "SAN" they mean Block storage devices and FC protocol, but it doesn't mean, that a file storage - NAS can't be connected with SAN and vice verse.