UFS2 with 4TB disk _totally absurd_

[Eric Anderson]

Scott Long wrote:
> Ensel Sharon wrote:
>>> The FDISK and bsdlabel schemes simply cannot deal with >2TB.  You'll
>>> need to either put your filesystem directly on the storage device
>>> without and slices/labels, or use GPT to create logical partitions.
>>
>>
>> 2TB filesystems are _not large_.  FreeBSD should expect 2-4TB filesystems
>> to be in common use in peoples _living rooms_, never mind in the 
>> office or
>> datacenter.
>>
>> So 5.x was a total wash in terms of UFS2 and snapshots, largefiles, etc.,
>> 6.0 still doesn't have working filesystem quotas or snapshots, and it
>> seems, doesn't support modern (circa 2004) hard drives.
>>
>> Maybe a little less time working on FreeBSD 23.0 ... ?
>>
> 
> What are you talking about?  UFS2, the filesystem, supports storage
> volumes up to 2^63 blocks in size, and filesystems themselves of
> more than 2^53 blocks in size.  There is no 2TB limit in UFS2, and I've
> personally created filesystems that are indeed much larger than that..
> These sizes were supported in 2004, and they are supported in 2006.
> What is limited is the FDISK and BSDLABEL formats, which were designed
> in the early 80's to handle up to 2^32 blocks.  Neither of these prevent
> you from creating a large filesystem.  Maybe you're looking to have a
> single large volume to hold both your boot filesystem and your data
> filesystem?  That's generally a bad idea since it puts more things into
> the path of a failure.  Try doing what most people do, which is to boot
> off of a 2 disk mirror (go big and get 500GB disks if you want) and have
> your data on a separate array that is more redundant and doesn't need to
> use the above partition formats.
> 
> Alternatively, find a PC that understands how to boot off of GPT
> partitions, and use that format.  It's not FreeBSD's fault that the PC
> BIOS uses the FDISK format.  Go complain to IBM and Microsoft for not
> having the foresight to future-proof their partition format 25 years
> ago.

Now if only fsck could be fixed to actually be able to fsck a full >2TB 
filesystem with a reasonable amount of memory, without swapping forever. 
  Even with journaling, you still need to be able to run fsck in case of 
very hard errors.


Eric



-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
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