Backup Central

I have a Linux server (RHEL5 64-bit, Dell R900 4 dual-core, 16GB memory, Quantum LTO-4 tape drive connected to a SAS1068E SAS card) that I am trying to archive data to tape (copy files to tape, remove files from disk).

The files in question are small in size but numerous (daily directories, about 30GB each day, about 150,000 files). I am using GNU tar v1.15.1 to write to the tape. The tape is rated at about 120MB/sec but I am only getting about 8-14 MB/sec. I have done some tests and it appears that throughput to the tape decreases as the number of files in the directory increases.

I have started to look for other solutions and wonder if there is solution that would work better than tar, something that can handle a large number of files.

Any help would be appreciated.

Try setting your tape drive to a variable block size:


mt setblk 0


Then try running tar with -b4096 for a 2MB block size. This may be part of the problem, but backing up a lot of small files will inherently be slow.