ontape

I need to know if ontape does any compression of data when it writes it to tape. Is there any way to control compression of data written to tape? We are using DLT tape drives on Sun Solaris machines. Thanks for any input. -- BillS Sent via Deja.com http://www.deja.com/ Before you buy.

Bill, AFAIK, there is no compression by ontape. However, the hardware compression on your tape system would be effective. We use DLT4000s and get almost 90Gb/tape. Doug "billybob" <whseverd@yahoo.com> wrote in message news:8nv24k$n9i$1@nnrp1.deja.com... > I need to know if ontape does any compression of data when it writes it > to tape. Is there any way to control compression of data written to > tape? We are using DLT tape drives on Sun Solaris machines. > > Thanks for any input. > > -- > BillS > > > Sent via Deja.com http://www.deja.com/ > Before you buy.

billybob wrote: > > I need to know if ontape does any compression of data when it writes it > to tape. Is there any way to control compression of data written to > tape? We are using DLT tape drives on Sun Solaris machines. Ontape does not compress. If your tape drives are capable of hardware compression and you either turn it on or use the compressing device driver file for the drive then ontape will take advantage of that. If you do use compression remember to set TAPESIZE accordingly and unless ALL of your columns are CHAR, VARCHAR or TEXT do NOT rely on the 50% compression the drive manufacturers advertise, only ASCII text compresses that well. Pure binary comes in at about 30% so estimate the ratio of text to binary and guess an appropriate size. Err on the low side as Informix will abort the archive if it detects the physical end of tape. An alternative is to archive to a pipe and have gzip read the pipe and output to the tape drive. Art S. Kagel