Re: Ontape to Disk

On Mar 12, 1:31 pm, kathy.duch...@state.mn.us wrote: > On Mar 12, 10:36 am, theBP <th...@Usenet-News.Net> wrote: > > > kathy.duch...@state.mn.us wrote: > > > I set the onconfig parameter TAPEDEV to STDIO and backed up a 2 > > > terabyte database to disk.  I have been told that restoring a database > > > over 1 terabyte from disk may not work.  Has anyone encountered or > > > heard of specific issues related to restoring a 2 terabyte database > > > from disk? > > > Version? > > Platform? > > Any limitations on the disk as regards filesystem? > > Informix 11.50FC3, Solaris 10, Intel.  The database is approx. 1.6 > terabytes and the disk space is set up for 2 terabytes Our company does something similar with Informix 11 on an IBM AIX platform. Just three caveats for you to think about, which we encountered: 1) Informix ontape does not seem to complain about the destination, be it a disk location or a tape drive. From our experiences, you are only limited by the maximum filesize you can create at the O/S level. In AIX, we ran into a 2GB limitation on the AIX "standard" file systems, and had to create these using either the AIX "large-file enabled" option, or switch to the Enhanced Journaled file system (jfs2). Make sure on your Solaris that they don't have some similar limitation on the storage directory (file system? logical volume? etc...) 2) Make sure that the "informix" user does not have a limit on the maximum filesize it can make. On the AIX platform, this meant changing a setting in /etc/security/limits (fsize = -1) 3) Are you planning to copy this 2TB ontape file off the disk at some point and onto removable media? Or just use that area as permanent storage for a copy of the instance, replacing it on a desired schedule? If you plan to write that large file to tape, you may encounter problems with commands like tar or cpio. I believe in both cases, the largest single file that can be saved in a tar or cpio archive is 2GB. We found this out the hard way. The ontape was extracting a 16GB instance to a file, then copying the file along with related software and configuration files onto a tape. No errors reported but upon reload, we found it had only saved the first 2GB of the ontape file on the backup tape.