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<== Date ==> <== Thread ==>

Subject: Re: EPICS iocLog file size limitation
From: Steve Lewis <[email protected]>
To: "Brian McAllister" <[email protected]>
Cc: [email protected] (Deb Kerstiens), [email protected]
Date: Thu, 21 Mar 2002 14:28:51 -0800
Actually, the inode contents of the inode are *NOT* modified;
the inode describes the disk sectors, which are not changed by
"mv".
 
"mv" modifies the old and new directories which associate the
hierarchical naming scheme with the in.

(All of the above applies within a single file system.  For
convenience, if the old and new directories are on different
file system, "mv" actually performs a copy and remove...which
will create one new inode and destroy one.)


At 12:56 -0500 2002/03/21, Brian McAllister wrote:
> >>> On 3/21/2002 at 10:39:16 MST, Deb Kerstiens wrote:
>
>  > I'm puzzled that "mv"ing the file results in having the logServer
>  > continue to write to the file in the new location, though. Maybe
>  > there's some system magic that keeps track of the file as long as it
>  > remains open for writing??
>
>Not magic, just standard Unix-style file I/O.  The file descriptor points
>to an "inode", not a physical disk location.  When you "mv" the file, the
>contents of the inode are modified to point to the new location, but it's
>still the same inode.  The "mv" is invisible to anyone who already has the
>file open.
>
>----
>Brian McAllister                    Controls Programmer/Beam Physicist
>[email protected]                        MIT-Bates Linear Accelerator
>(617) 253-9537                                           Middleton, MA


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References:
Re: EPICS iocLog file size limitation Brian McAllister

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