DDS4 drive on g-class

[radi_1]

hi,
I need to know if i can connect an internal hp dds4 tape unit to a G-class hp-ux(v.11.0) server,is there a driver issue involved?or all i have to do is plug it in and the o.s will take care of all issues?am going to give it a try in 2 hours time but i need to know befor hand,Please advice.
Regards.

[Leif Halvarsson_2]

Hi,
I can see no reason why it not should work. Of course you must have the drivers configured in the kernel. Use SAM and add the "stape" and "tape2" driver to the kernel.

[radi_1]

Hi Leif,the stape driver is allready (IN)because A DDS3 unit is on and running,the customer needs to have 2 simultanuos backups, that's why i need to install the available DDS4.But your suggestion of tape2 driver is helpfull and i will take note of it,thanks

[Bill Hassell]

The G-class is extremely slow and the DDS4 tape drive is 3 times faster than the DDS3. Modern tape drives are streamers, that is, they are designed only to run at full speed. When a slow (or busy) system cannot keep up with the tape drive, the tape is stopped, backed up and restarted, thus severely degrading throughput and increasing wear on the drive and tape. The DDS3 needs 1Mb/sec while the DDS4 needs 3Mb/s. Note that these numbers must be higher (as much as 2x or more) for compressible data.

Today, those data rates are trivial but the G-class is more than 15 years old with CPU speeds between 48 and 96Mhz. Couple the slow processor with relatively slow disks and the G-class will likely create data starvation. This can increase the backup time from 5 to 10 times longer (significantly slower than the DDS3).

If you are using tar or cpio or similar tools for backup, the overhead for locating, opening and closing each file will be significant on the G-class. To keep the DDS4 busy, you'll need to use fbackup with a config file specifying 6 reader processes. There is no simple way to predict success otgher than thousands of small files (less than 1Mb) will really slow down the backup and increase drive wear.

[Torsten.]

AFAIR the tape2 driver is the only possible driver for your server, but this driver is *not* aware of a dds4 drive. so you cannot use this drive with your server.

[TwoProc]

Wow,

sniffle... bawl... cry... wheeze...

...

I learned lvm on a G box...

Bwaaaa auuuuuugh Bwaaaa auuuughhh...

sniffle...

( I miss the old days )

sniffle...

[Bill Hassell]

Hey John, I've got a G30 with 256Mb RAM, a DDS2 drive and a couple of internal 2Gb drives. It runs 10.20 just fine. Want it? I've also got an E35. Sorry, I don't have an 840 (the first HP 9000 server) but it only runs 9.0 and earlier.

[Steven E. Protter]

Shalom,

The tape drive should work, but watching it make tapes would make me want to pull my hair out.

I don't think there will be a driver issue.

SEP

[TwoProc]

Cool offer Bill (actually very generous thank you!), but I've found out over the years, it's often better to reminisce about the old days than it is to actually go there.
I REALLY don't miss having to take that thing down sooo far just to fool with the hard drives. As a contrast, I remember being so happy with D-390/2 boxes with hotswap bays in the front. I liked them so much, I kept them all, and still run & use them. So, as much I loved all the learning on our G30,G50 & I70 servers I don't really want to go back there. I specifically liked the G-class of h/w so much b/c our 720s, 730s and our Apollo systems could only use hard partitioning b/c you couldn't load lvm on them (HPUX 8 & 9).

[radi_1]

Thanks to all your replies,
It did not work,the kernel did see the tape but backup failed because of I/O error

[radi_1]

No I/O to the DDS4 tape unit.