Re: 3TB disk hassles

From: Jeff V. Merkey
Date: Mon Jan 03 2005 - 12:06:55 EST


H. Peter Anvin wrote:

Andries Brouwer wrote:


Concerning one, it is a somewhat complicated format that takes over
your disk, rather inconvenient. It seems to me that one needs a good
reason (like a BIOS that understands the format and is able to boot
from it) to choose it.


Not really; it's actually a very simple table.


It would be nice to know when this is going to make it in for my Linux projects.
I am running a 3Ware 9500 series with 3.1 TB disks. I am able to use all the
storage at present with dsfs. dsfs can support volumes up to 281 TB at present
but linux readir() can get into some problems when directories get really large.

I am not seeing problems with files that are 1.5 TB in size. Have not tried to
create a 3TB file yet, but in theory, the VFS looks to support it. I am getting around the
partition problem by basically ignoring the table extents (fdisk is broken with these large
partitions and wraps back to 700GB) if I have only created a single partition, I just query
the drive geometry and take the remaining space on the device and I ignore the partition
table. It works fine. If I detect more than one of my partitions I revert back to the actual
partition dimensions.

For Jens edification, I am using the BIO subsystem with this and I am seeing no problems
reading and writing these huge drives, so I think Linux 2.6.9 and 2.6.10 will support this
well, and appears to. I will be testing a combined striped array at around 20TB with multiple
controllers and FC/AL and will update if any problems are encountered.

Other than the partition problem, the base kernel seems to support these huge sizes with
64 bit LBA addressing very well.

Jeff

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