Jon,
Jon Lewis wrote:
> I just had someone add a DDS2 DAT to a remote server, and though they
> claim it has a DDS2 tape in it, the drive says it's using DDS1. To see if
> it was reporting bogus info, I made a file of 1mb from /dev/urandom, and
> sent 3139 copies of that file to /dev/nst0 before it told me it was out of
> space.
I've never used /dev/urandom -- do you know just how "random" the data
is? Truly random data will result in expansion if hardware compression
is turned on. Also, when you say 1MB file, do you mean a file of size
1,000,000 bytes, or a files of size 1,048,576 bytes? The DDS2 spec of
4GB is actually 4,000,000,000 bytes, not 4GB bytes where each 1KB is 1024.
> That's better compression than I expeced from /dev/urandom, but
> seems to confirm I'm not getting 4gb native. The drive ids as:
>
> Host: scsi0 Channel: 00 Id: 01 Lun: 00
> Vendor: SONY Model: SDT-7000 Rev: 0300
> Type: Sequential-Access ANSI SCSI revision: 02
> # mt -f /dev/nst0 status
> SCSI 2 tape drive:
> File number=3139, block number=1, partition=0.
> Tape block size 0 bytes. Density code 0x13 (DDS (61000 bpi)).
> Soft error count since last status=0
> General status bits on (1010000):
> ONLINE IM_REP_EN
>
> mt -f /dev/nst0 setdensity 0x24 results in:
>
> /dev/nst0: Input/output error
> st0: Error with sense data: extra data not valid Current error st09:00:
> sense key Illegal Request
> Additional sense indicates Invalid field in parameter list
The above might be due to mt sending a command with a bit set which the
drive doesn't like. I've got a 7000 drive myself so I'll check it out tonight
and send you additional info.
> The tape should be one of several TDK DDS2 cartridges I just sent to the
> remote site.
These are DDS cartridges, not 120m audio DAT tapes, correct?
> Anyone know how to convince the drive to write DDS2?
Trust me, if the tape is DDS2, the drive will write DDS2. I don't care what
density it reports. There are many reasons for not achieving the full
capacity. Putting a DDS2 tape in and having the drive write DDS1 is NOT
one of them.
Pete
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to [EMAIL PROTECTED]
