I believe the tape label command is reporting 2 TB not 2PB: 2147483648 <2147483648> x 1k = a 2 followed by 12 digits or Terabytes.
Anyway I did some testing to prove the limit is 2TB's and also to test out my new LTO5 tape under Red Hat 6.4 and compression is working and the performance seems ok. I Created a partitions with 10 volumes each containing one 10GB text file which gives a partition with 100GB of data. The text file contains the same character and is highly compressible. Did repeated appended dumps to the same lto5 tape. The tape did stop at 2TB after 21 full dumps and a partial dump on the 22 dump. Here is the backup command status: backup> stat 3 Task 3023: Dump: 2147483664 Kbytes transferred, volume NB.usr1.backup [operator wait] and as expected butc prompts for a tape: ******* OPERATOR ATTENTION ******* Device : /dev/st0 Please put in tape crow_daily.Full.2 (1369966302) for writing and hit return when done On Tue, May 28, 2013 at 2:39 PM, chas williams - CONTRACTOR < c...@cmf.nrl.navy.mil> wrote: > On Tue, 28 May 2013 13:56:07 -0400 > John Sopko <so...@cs.unc.edu> wrote: > > > According to the docs and the output from butc the max tape size > > in the /usr/afs/backup/tapeconfig file is 2TB. I set to 8TB and labeled > > a tape and it appears to be limited to 2TB as shown below. > > There are a few afs_int32's hanging around in that code that should > probably should be afs_uint32's. This would possibly double tape > capacity to 4TB without too much work I think. A real fix for this > problem would require quite a bit more work. > > > Tape blocks read in 10240 Byte chunks. > > Labelled tape <NULL> size 2147483648 Kbytes > > Cleverly, this is reporting 2PB but I think the programmer meant bytes > here. > -- John W. Sopko Jr. University of North Carolina email: sopko AT cs.unc.edu Computer Science Dept., CB 3175 Phone: 919-962-1844 Fred Brooks Building; Room 140 Fax: 919-962-1799 Chapel Hill, NC 27599-3175
