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Date: Tue, 05 Jun 2012 05:08:03 +0400
From: George Shuklin <george.shuklin@gmail.com>
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To: "H. Peter Anvin" <hpa@zytor.com>
CC: Casey Schaufler <casey@schaufler-ca.com>,
        Al Viro <viro@ZenIV.linux.org.uk>,
        linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Why minor is still 8 bit?
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On 05.06.2012 04:52, H. Peter Anvin wrote:
> On 06/04/2012 11:59 AM, George Shuklin wrote:
>> Very simple sample: I'd like to create shared storage to publish volumes
>> via ISCSI. ~60Tb of drives, ~2Gb average disk size = 30k disk images.
>> Can I just create a bunch of LV and export them by iet or scst? Nope:
>> There is a serious limit for amount of active LV per host. Yes, I can
>> create filesystem, put images (as file) to that filesystem and publish
>> them back, but why FS is needed to do such simple task?
> You realize that with that many volumes, a logical volume manager *is* a
> filesystem, right?
>
> 	-hpa

Well, I have nothing against filesystem with very small 'db-like' 
footprint: no directories, no attributes, extra-large allocation block, 
very fast initialization, no random file growth (very calm metadata 
without constant updating). If someone do have that type of FS (for disk 
images storage) - why not?

Anyway, using LVM to provide logical volumes to customers seems be fine 
(at least by name). But that limitation for minor is breaking whole idea.

I don't ask 'please fix', I'm just curious why so small?