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