How to check file system(Data) consistency in case of NFS i/o ?

[zorba]

Hi,

How to check file system(Data) consistency in case of NFS i/o ?

thanks & regards
Parinay

[bcwalrus]

Post by zorba
Hi,
How to check file system(Data) consistency in case of NFS i/o ?
thanks & regards
Parinay

The question is quite unclear. Consistency is a relation between two
things. Can you tell me what the two things in your question are? It
could be consistency between what the server receives and what's in
the file system, or what the server receives and what appears on disk,
or what the client sends and that the server receives, and so on.

Cheers,
bc

[zorba]

Post by bcwalrus

Post by zorba
Hi,
How to check file system(Data) consistency in case of NFS i/o ?
thanks & regards
Parinay

The question is quite unclear. Consistency is a relation between two
things. Can you tell me what the two things in your question are? It
could be consistency between what the server receives and what's in
the file system, or what the server receives and what appears on disk,
or what the client sends and that the server receives, and so on.
Cheers,
bc

What the client sends and that the server receives ...

[bcwalrus]

Post by zorba

Post by bcwalrus

Post by zorba
Hi,
How to check file system(Data) consistency in case of NFS i/o ?
thanks & regards
Parinay

The question is quite unclear. Consistency is a relation between two
things. Can you tell me what the two things in your question are? It
could be consistency between what the server receives and what's in
the file system, or what the server receives and what appears on disk,
or what the client sends and that the server receives, and so on.
Cheers,
bc

What the client sends and that the server receives ...

The only cause of inconsistency there (that I can think of) is data
corruption when the packets are in the network. The transport layer is
supposed to prevent that. Are you using TCP or UDP? Both have "good
enough" checksum for most people. If you're paranoid, you can use
Kerberos signing with NFS.

Cheers,
bc

[zorba]

Post by bcwalrus

Post by zorba

Post by bcwalrus

Post by zorba
Hi,
How to check file system(Data) consistency in case of NFS i/o ?
thanks & regards
Parinay

The question is quite unclear. Consistency is a relation between two
things. Can you tell me what the two things in your question are? It
could be consistency between what the server receives and what's in
the file system, or what the server receives and what appears on disk,
or what the client sends and that the server receives, and so on.
Cheers,
bc

What the client sends and that the server receives ...

The only cause of inconsistency there (that I can think of) is data
corruption when the packets are in the network. The transport layer is
supposed to prevent that. Are you using TCP or UDP? Both have "good
enough" checksum for most people. If you're paranoid, you can use
Kerberos signing with NFS.
Cheers,
bc

I am using TCP but no kerberos.
Can you explain( if you have time ) the other 2-relations that you
mentioned w.r.t. consistency (i.e.consistency between what the server
receives and what's in the file system, or what the server receives
and what appears on disk ) ?

[bcwalrus]

Post by zorba
I am using TCP but no kerberos.
Can you explain( if you have time ) the other 2-relations that you
mentioned w.r.t. consistency (i.e.consistency between what the server
receives and what's in the file system, or what the server receives
and what appears on disk ) ?

The data typically travels through this path:

user program --> client VFS/NFS --> network --> server NFS/VFS -->
server underlying FS (ext3, reiser, xfs, etc.) --> disk

If you're using a stable OS, the NFS/VFS layers are unlikely to
corrupt your data. If you're using an experimental file system, or
have a faulty disk, then you should check there first. What kind of
data inconsistency have you observed?

Cheers,
bc