Subject Re: [firebird-support] Embedded Database from server share.
Author Ann W. Harrison
S C wrote:
> The problem is that I cannot setup a server in the work environment to host
> the firebird server. My PC is not always going to be on. So installing the
> server there would not be stable enough. It just seem to me that embedded
> should work on any drive type. Why does it matter if its a network drive.

Because if you happen to open the same database from two different
embedded engines on two different PC's, they'll trash the database.
And, as far as I know, the second PC has no reliable way of knowing
that the file has been opened elsewhere. If we had a reliable way
of identifying conflicts, we would allow connections to files on
shared drives. Without that, there's too much risk. However, if
you really like living on the edge, here's the parameter - and
warning - from the configuration file.

# ----------------------------
# Remove protection against opening databases on NFS mounted volumes
# ***WARNING*** ***WARNING*** ***WARNING*** ***WARNING***
# This option removes an important safety feature of Firebird and can
# cause irrecoverable database corruption. Do not use this option unless
# you understand the risks and are prepared to accept the loss of the
# contents of your database.
# Unless this configuration option is changed from 0 to 1, Firebird can
# open a database only if the database is stored on a drive physically
# attached to the local computer – the computer running that copy of
# Firebird. Requests for connections to databases stored on NFS mounted
# drives are redirected to a Firebird server running on the computer that
# "owns" the disk.
# This restriction prevents two different copies of Firebird from opening
# the same database without coordinating their activities. Uncoordinated
# access by multiple copies of Firebird will corrupt a database. On a local
# system, the system-level file locking prevents uncoordinated access to
# the database file.
# NFS does not provide a reliable way to detect multiple users of a file on
# an NFS mounted disk. If a second copy of Firebird connects to a
database on
# an NFS mounted disk, it will corrupt the database.
# Under some circumstances, running a Firebird server on the computer that
# owns NFS mounted volumes is inconvenient or impossible. Applications that
# use the "embedded" variant of Firebird and never share access to a
# can use this option to permit direct access to databases on NFS mounted
# volumes.
# Type: boolean
#RemoteFileOpenAbility = 0