How to read a Zombie file?

[keemoot]

Hello,

I was saving data in a ROOT file as a ROOT Tree with several brunches. However for some reason my PC crashed and the root file was not closed properly. See following output as I tried to read the file:

root [1] TFile f(“data.root”)
Warning in TFile::Init: file data.root probably not closed, trying to recover
Warning in TFile::Init: no keys recovered, file has been made a Zombie

Is there any chance to get the data or to repair this file?
Can I maybe recover the needed internal keys?

Thanks in advance!!

I use ROOT 4.00/08

[brun]

see root.cern.ch/root/htmldoc/TTree. … e:AutoSave

If you did not call TTree::AutoSave, no way to recover the keys, since no keys have been written.

Rene

[keemoot]

Ok,

the keys can not be recovered; but what about the data; it is maybe still possible to get them; maybe to extract the data and to convert to another format, e.g. ASCII. I will appreciate any proposal, even if it is a messy work.

Thomas

[brun]

It is theoretically possible to rebuild the Tree by reading the basket buffers from the file if you have another file containing a TTree with
exactly the same structure (number of branches and branch types).

This will require some work (not possible in the coming days), but
it is doable.

Rene