[Zope] Backing Up Zope (was: Re: [Zope] Data.fs.lock?)

[Toby Dickenson]

On Thu, 29 Jun 2000 17:19:32 -0400, Shane Hathaway
<shane@digicool.com> wrote:

>Quite simply, Data.fs is appended, not modified, except during a pack
>operation.  Think of it like a binary log file.  Therefore there are
>only two ways a simple, live backup of Data.fs can fail:
>
>1) You do the copy in the middle of a pack operation.  For most,
>packing is a rare operation.  But if this happened, your backup would
>be worthless.

I think its better than that. FileStorage packs itself into a
temporary file, which is renamed to data.fs only when the pack is
complete.

>2) You get a partly truncated record at the very end.  This is actually
>not a big deal, and AFAIK in most cases ZODB is capable of
>automatically rolling back a partially committed transaction.


I think the other exception is during an Undo, where Zope will rewrite
one byte in the middle of the file.


Toby Dickenson
tdickenson@geminidataloggers.com