Re: questions about TZ88N-VA

From: John Reinhardt (johnhreinhardt_at_yahoo.com)
Date: 08/20/04 

Date: 20 Aug 2004 02:18:54 -0700

>
> I have mostly SCSI-1 (5 Mb/s), some fast narrow SCSI-2 (10 MB/s), mostly
> VA disks internal or in BA350 or BA353 shelves, some VW disks in BA356
> shelves (all of these are on the 10 Mb/s SCSI). When doing a backup to
> the DLT system mentioned above from a) a disk on the same SCSI bus, b) a
> disk with a direct connection to the same machine and c) to an
> MSCP-served disk, what will be the bottleneck: disk speed, SCSI-bus
> speed, tape-drive speed or network speed (only a possibility in the last
> case, obviously)?

  If you find the Systems and Options (SOC) archives on the HP website
and look up the TZ88 in the tape drive section (
http://h18002.www1.hp.com/products/quickspecs/SOC/QB00DPPF.PDF )you
will find that the information given there says the "TZ88 is
read/write compatible with the TZ85, TZ86, TZ87 and TZ88. TZ88 uses
DLT/CompacTape IV media and is read/write compatible with,
DLT/CompacTape III, and DLT/CompacTape IIIXT media."

  When using a DLT IV make sure that it hasn't been previously used on
with a DLT7000 (TZ89) or DLT8000 drive since they also use the same
cartdridge but at a higher density (35/70GB or 40/80GB) than the TZ88
can handle. If this is the case, the TZ88 will give an error when
trying to load the tape. The only way I know of to remedy that is to
use a degauser and erase the tape manually.

The SOC also says the drive's native transfer speed is 1.5MB/sec and
the compressed speed is up to 3.0MB/sec. Ths means that in senarios
(a) and (b) it may be a toss-up as to what is the bottleneck as quite
a few SCSI-1 and some SCSI-2 drives will be hard pressed to sustain a
transfer rate of 3MB/Sec and if both the hard drive and the tape drive
are on the same bus it may be the bus bandwith that is the limit. In
senario (c) the network will be the limiting factor if you have a
10baseT network and probably even if you have a 100baseT although the
throughput of the MSCP server may be a factor also.

  Also in the SOC documents under Storage Enclosures (
http://h18002.www1.hp.com/products/quickspecs/SOC/QB001QPF.PDF ), it
lists the TZ88Z-VA supported for the BA350 (BA356 also) shelf.

Relevant Pages

  • Re: questions about TZ88N-VA
    ... > the DLT system mentioned above from a) a disk on the same SCSI bus, ... will find that the information given there says the "TZ88 is ... a few SCSI-1 and some SCSI-2 drives will be hard pressed to sustain a ... are on the same bus it may be the bus bandwith that is the limit. ...
    (comp.os.vms)
  • Re: Windows Disk Drive Device Names
    ... are 3 drives attached to the 39320 controller, ... Disk Managment ...
    (microsoft.public.windowsxp.hardware)
  • Re: (S)ATA performance in FBSD 6.2/7.0
    ... I never got beyond 33 MB/s transfer rate although bonni/bonni++ told me both drives are capable doing much more. ... Two Hitachi T7K250 250 GB/SATA II drives build up a RAID 0, and additionally there is a SAMSUNG Spinpoitn SP2004C attached to the controller. ... For example, if you have two devices on the same bus, then each byte of data copied has to pass over the bus twice, which may run into performance limits on the bus where moving the data over the bus once won't. ... disk performance varies enourmously by location where the I/O is taking place on the disk. ...
    (freebsd-questions)
  • Re: (S)ATA performance in FBSD 6.2/7.0
    ... I never got beyond 33 MB/s transfer rate although bonni/bonni++ told me both drives are capable doing much more. ... Two Hitachi T7K250 250 GB/SATA II drives build up a RAID 0, and additionally there is a SAMSUNG Spinpoitn SP2004C attached to the controller. ... For example, if you have two devices on the same bus, then each byte of data copied has to pass over the bus twice, which may run into performance limits on the bus where moving the data over the bus once won't. ... disk performance varies enourmously by location where the I/O is taking place on the disk. ...
    (freebsd-performance)
  • Re: can I use flashdrive as page file for enhanced computer perfor
    ... 1.Would the flashdrive bus be the same as the boot hard drive? ... Not likely -- unless your hard-drives are antiques. ... USB 2.0 has a maximum throughput of just 480 Mbits/s, ... connected all four IDE drives to your motherboard's IDE interface, ...
    (microsoft.public.windowsxp.general)