topic Re: Total size of data backup in Operating System - HP-UX

Total size of data backup

YMJ — Wed, 30 Mar 2005 07:20:36 GMT

Hi all

I want to know if fbackup has the capability of knowing the size of backuped data before the doing the backup?

or any other way to know that?

I have DSS3 drive and it seems that the data can't fit into 24GB compressed disk.

Re: Total size of data backup

harry d brown jr — Wed, 30 Mar 2005 07:50:12 GMT

Nope.

Is the problem having to us two or more tapes? The answer would be: Buy an LTO or DLT.

live free or die
harry d brown jr

Re: Total size of data backup

Florian Heigl (new acc) — Wed, 30 Mar 2005 07:57:05 GMT

Hi,

the problem is that fbackup won't know how well the data is going to be compressed.

with regular data, I usually assume reaching no more than 20% of the uncompressed data capacity.

also, check if You're using data compression on the DDS drive, to my knowledge HP-UX does *not* activate it.

I just read to the man page, and it appears fbackup doesn't compress data by itself either, this is the only time compression is mentioned:
"If sparse files are backed up without using data compression, a very large amount of media can be consumed."

maybe someone can fill in on that, I don't use fbackup more than once a year or so :)

If You want a compressing tape device file, You usually have to add it using mksf.

Florian

Re: Total size of data backup

Leif Halvarsson_2 — Wed, 30 Mar 2005 08:33:07 GMT

Hi,
Check with "du -ks" before starting fbackup.