[CentOS] 2 TB limit on USB drive

Todd Denniston Todd.Denniston at tsb.cranrdte.navy.mil
Tue Nov 17 00:14:47 UTC 2009

Gareth Tupper wrote, On 11/16/2009 03:12 PM:
> Hallo
> I submitted this as a bug several weeks ago, but I wanted to ask around
> & see if anyone else has come across this....
what BZ and #? (mainly out of curiosity, but not enough to override the laziness of not wanting to 
check 2 different BZs)
> 	I have a USB Buffalo Drivestation Quattro, with 4 1TB disks
> configured in raid5 as one 2.8TB (or so) disk, attached to a Cent 5.4 64
> bit server (completely yum'd up to date)
> After this failure, the disk is either a) inaccessible, or b) reports
> only a 2 TB partition.
> [root at myserver ~]# cat /proc/partitions
> major minor #blocks name
>    ...
>    8 32 2147483648 sdc << the disk showing incorrectly with only 2TB of
> storage
> This bug seems very similar to a previous bug:
> https://bugzilla.redhat.com/show_bug.cgi?id=502944 which was reported
> fixed in 5.4 
> Anyone seen this before, or have any ideas how I can get CentOS to see
> the disk?

A1) figure out how much more/less than
needs patched into the kernel source to make >2TB work.
A2) get the CentOS kernel SRPM and patch it in, build, install and use.
[considering the bz you point to points to (in Comment #7) a very small patch for the ipbvscsi 
devices, it is _probably_ just a simple patch from the 24 version of usb.c]

B1) give a kernel dev at that prominent North American Enterprise Linux vendor (who runs Enterprise 
Linux instead of Fedora) a 2.8TB USB disk to play with and
B2) point them at http://www.linuxhq.com/kernel/v2.6/24/drivers/usb/storage/usb.c


Alternatively we could find someone with a 2+TB USB disk and the ability to submit bugs on a 
subscription to that prominent North American Enterprise Linux vendor.
(or see if a proven change could be put in a CentOS plus kernel[module])

Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter

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