Re: [Iscsitarget-devel] Re: [ANNOUNCE] iSCSI enterprise target software

[Libor Vanek <lvanek@terra.cz>]

Arjan van de Ven wrote:

>On Tue, 2005-03-01 at 19:22 +0900, FUJITA Tomonori wrote:
>  
>
>>From: Arjan van de Ven <arjan@infradead.org>
>>Subject: [Iscsitarget-devel] Re: [ANNOUNCE] iSCSI enterprise target software
>>Date: Tue, 01 Mar 2005 10:46:03 +0100
>>
>>    
>>
>>>fsync or msync() ? I would imagine the target mmaping it's backend in
>>>userspace and using msync() to kick off IO. At which point it's not that
>>>much different from the control you do of the pagecache from inside the
>>>kernel...
>>>      
>>>
>>Can we avoid calling mmap() and munmap() repeatedly with large disk?
>>    
>>
>
>my server has 512Gb address space with 2.6.9/2.6.10, and a lot more than
>that with the 2.6.11 kernel (4 level page tables rock). So the answer
>would be yes.
>
>(and on old servers without 64 bit, you indeed need to mmap/munmap
>lazily to create a window, but I suspect that the 3 Gb of address space
>you have there can be managed smart to minimize the number of unmaps if
>you really try)
>  
>
I don't know in detail what are you talking about (if whole disk must 
fit address space) but please consider we're speaking about TBs (10-20 
TB RAID is quite cheap nowadays with 400 GB SATA disks).

-- 
Best regards,
Libor Vanek