Hello All,
Attached is a conversation I've had with an old friend / colleague /
sysadmin (cc'ed) and it raises three questions for me.
I would like to ask the panel, from the context as described below:
Did Sol9 have a 1Tb limit on addressing IDE
Does S10?
Would ZFS be impacted if using >1Tb IDE devices?
...along with any general constructive commentary/feedback on the
issue described...
Thanks,
- alec
---- snip snip ----
him:
>The terabyte drive is on the way.. I just hope OS writers can keep
>up; it's the underlying disk access layer that has problems.
>Solaris uses a pseudo-SCSI interface for IDE, which runs out of CHS
>at 1TB. This is why our 4.2TB RAIDs had to be split into 5 virtual
>drives. I don't know how the FC interface gets over that problem.
me:
>so you are presenting your raid arrays as C/H/S IDE using a raid
>controller, at sizes > 1Tb ?
him:
>Nope, they are being presented as SCSI devices, but Solaris seems to
>treat IDE drives as pseudo-SCSI devices, at least from the
>programming point of view.
me:
>Can you paste me a uname -a on the pertinent machine? I want to ask
>a few people
him:
>SunOS mariner 5.9 Generic_112233-11 sun4u sparc SUNW,Sun-Blade-100
>
>That's the machine which has a Ultra-3 SCSI host adaptor to which is
>connected a RAID system.
me:
>Any other information that you think is pertinent ?
him:
>[it appears that] format can't handle a drive bigger than
>65535/128/128 (as that's all the sd data structures can handle)
>
>Sorry [make that] cyl 65535 alt 2 hd 256 sec 128
>
>If it could handle 256 sectors per cylinder then it could cope with
>up to 2TB. Not that it's a problem at the moment. It's just a pity
>that the underlying SCSI sub-system can't handle device sizes large
>enough to handle the filesystems which can live on them.
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