Thread: Filesystem crash - corupted database
Hi, It's possible to extract data directly from data files ? I have two tablespaces one for data and one for indexes. After filesystem crash I lost my /var/lib/postgresql/data folder :( All data is in /lost+found :(, I found folders with data and index tablespe that looks ok. It's possible to directly access these files and extract data as CSV for example ? Or it's possible "mount" these tablespaces to new database instance ? Thnx for advice Bedy btw: I know - restore from backups, but DB is too big, and I have backups 6days ago.
On 9/26/07, Martin Bednář <bednar@triax.cz> wrote: > Hi, > > It's possible to extract data directly from data files ? > I have two tablespaces one for data and one for indexes. > After filesystem crash I lost my /var/lib/postgresql/data folder :( All > data is in /lost+found :(, I found folders with data and index tablespe > that looks ok. > It's possible to directly access these files and extract data as CSV for > example ? > Or it's possible "mount" these tablespaces to new database instance ? You can read them with a hex dump program, but that's about it. The data may well be too corrupted to use anyway. OTOH, if the files are intact and you can rename them back to what they were you might be able to get your db back up. But I wouldn't count on it. > btw: I know - restore from backups, but DB is too big, and I have > backups 6days ago. That's why there's PITR. If you had been backing up with PITR, then you could roll forward your standby machine and be right back up. Use this to make a case to the powers that be that you need better backup procedures and hardware to handle your data. The cost of your data is much higher than the cost of the hardware it lives on.
On Wed, Sep 26, 2007 at 11:59:28AM +0200, Martin Bedná? wrote: > Hi, > > It's possible to extract data directly from data files ? > I have two tablespaces one for data and one for indexes. > After filesystem crash I lost my /var/lib/postgresql/data folder :( All > data is in /lost+found :(, I found folders with data and index tablespe > that looks ok. > It's possible to directly access these files and extract data as CSV for > example ? > Or it's possible "mount" these tablespaces to new database instance ? In theory if you resurrect the schema exactly as it was, and then copy the old files in place, you *may* be able to read them. However, you're going to have trouble with non-existing XIDs. Yo umight be able to recreate the XLOG/CLOGs but the whether it's going to be consistant is anyones guess... Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.