I've been testing our backups here at my office. After I write the tar file to the tape drive and remove it, the cksum & md5sum are different. I tried small files at first, with cksum it was different everytime.

If I turned hardware compression off on the st, the md5sum came up the same on a small file. When I tried our 5.5GB tar file, the md5sum came out different. I untar'd the file and pulled everything out of it, as far as I could tell, everything's the same. Should I be alarmed by this?

The only differences are this, the original is named nightly-backup.tar and located in /backups. After it's writen to the tape, it's renamed to lastweek-backup.tar. I pulled the original off the tape and stored in /backups/restore as nightly-backup.tar. Will this cause the differences?

This is what I get from an md5sum of the two:

f9a64b1c9c54e0316141c0f4a85e4ea7 lastweek-backup.tar
3036927f219a752359bf5b005a2e7e99 nightly-backup.tar

This is what I get from a cksum of the two:

251230307 5562952704 lastweek-backup.tar
1523033174 5562952704 nightly-backup.tar

Any help is appreciated.

TIA.

PS
I did a search before posting and couldn't find anything helpful, but I may not know what it is I'm looking for...

**BUMP**

Anyone???

Some one on another forum posted:

"I don't have that much tape drive experience, but I think I know what it is. If I recall correctly, the tape doesn't keep an EOF record, and thus it reads until the last of the stored block. Thus, if the tar file's size isn't a multiple of the tape's block size, the read file will have some trailing garbage. Tar will ignore the trailing garbage, but md5sum naturally won't."

Could this be the cause of my differences?