Hi all, I wanted to follow up to a number of threads we've already had about Bacula performance with LTO-3 and LTO-4 drives.
The lowest-level way to test the drive performance is to use a utility provided by the drive manufacturer. For IBM drives, there is a utility called ITDT. Here are my results from ITDT: The machine is an IBM x3650 with 2 x Xeon 5150, 8GB RAM. The controller is a SAS1068E: > 10:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E > PCI-Express Fusion-MPT SAS (rev 02) > Subsystem: LSI Logic / Symbios Logic Unknown device 3100 > Flags: bus master, fast devsel, latency 0, IRQ 106 > I/O ports at 6000 [size=256] > Memory at b7ffc000 (64-bit, non-prefetchable) [size=16K] > Memory at b7fe0000 (64-bit, non-prefetchable) [size=64K] > [virtual] Expansion ROM at b4000000 [disabled] [size=2M] > Capabilities: [50] Power Management version 2 > Capabilities: [68] Express Endpoint IRQ 0 > Capabilities: [98] Message Signalled Interrupts: 64bit+ Queue=0/0 > Enable- > Capabilities: [b0] MSI-X: Enable- Mask- TabSize=1 > Capabilities: [100] Advanced Error Reporting It connects to three LTO-4 SAS drives (in an IBM TS3310) via a 4-to-1 multiplexer dongle. 0.5m SAS cables. With the machine idle, tape drives idle, I load a new tape into a drive and run itdt and the "full write" test, with "compressible" and "incompressible" data: > Block Size Data Size Elapsed Data Rate > > Serial No: (KB) (MB) Time (s) (MB/s) > > +---------------+ +----------+----------+----------+---------+ > > | 1310023210 | | 512 | 83923 | 1106.17 | 75.8684 | > > +---------------+ | 256 | 83923 | 1122.65 | 74.7544 | > > | 128 | 83923 | 1865.06 | 44.9977 | > > C/I: Total KB: Comp.Ratio | 64 | 83923 | 3354.12 | 25.0209 | > > +--+----------+---------+ | 32 | 83923 | 6320.65 | 13.2776 | > > | C| 445732624| 93.65 | | 16 | 15669 | 2288.65 | 6.84673 | > > +--+----------+---------+ | 8 | | | | > > | 4 | | | | > > +---------------+ | 2 | | | | > > Result: | ABORTED | | 1 | | | | > > +---------------+ +----------+----------+----------+---------+ > > Code: Bin Log: Text Log: > > +------------------+ +--------------------++--------------------+ > > | ABORTED BY USER | | 1310023210.blz || 1310023210.txt | > > +------------------+ +--------------------++--------------------+ > > > > [R] Return to device list > > <[Q] Quit | Command > > > Block Size Data Size Elapsed Data Rate > Serial No: (KB) (MB) Time (s) (MB/s) > > +---------------+ +-----------+-----------+-----------+-----------+ > > | 1310023210 | | 512 | 83923 | 1109.09 | 75.6683 | > > +---------------+ | 256 | 83923 | 1141.26 | 73.5357 | > > +-+ | 128 | 83923 | 1873.68 | 44.7906 | > > Comp./Incomp.:|I| | 64 | 83923 | 3369.68 | 24.9054 | > > +-+ | 32 | | | | > > | 16 | | | | > > | 8 | | | | > > Curr. block size: | 4 | | | | > > +----------+ | 2 | | | | > > | 32 |(KB) | 1 | | | | > > +----------+ +-----------+-----------+-----------+-----------+ > > > > Remaining (KB): Progress: Status: > > +---------------+ +--------------------+ +-------------+ > > | 82426120 | | | | FULL WRITE | [A] Abort > > +---------------+ +--------------------+ +-------------+ > Doing something like "dd if=/dev/urandom of=/tmp/test_file_10G bs=1M count=10000" then "dd if=/tmp/test_file_10G of=/dev/nst0 bs=X" gives me almost exactly the same results. If the formatting is all screwed up, trying viewing the message as text. Regards, Alex ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
