[LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[Andiry Xu]

Hi,

I would like to attend LSF/MM to present a new file system design for
non-volatile main memories.

The goal of NOVA is to provide high performance and strong consistency
(atomic metadata, data, mmap updates) at the same time.

Although NOVA is a LFS, as it targets a different memory technology,
it looks very different from conventional LFS. Some of the key design
decisions of NOVA include:

Per-inode log: Each inode has a log, with tail pointer points to the
latest committed entry. This allows for high concurrency and parallel
log scanning.

Log is a linked list: Allows for fine-grained, page-size granularity
garbage collection. Also, allocating log space is easy since NOVA does
not need to allocate large, contiguous space for logs.

Cheap atomicity: To atomically append a log, NOVA simply appends the
log entry and then updates the log tail pointer. To coordinate updates
across logs, NOVA appends each log and journal the log tails to update
all logs atomically. This mechanism has lower overhead than journaling
(which doubles writes) and shadow paging (which causes cascade
updates).

Stores file data outside the log: NOVA appends metadata of writes to
the log and handles file data in a copy-on-write way. This results in
a shorter log, and garbage collection is simple and efficient, as NOVA
never copies data in log cleaning.

Highly scalable: NOVA has free list, journal and inode table at each
CPU to avoid global locking and scalability bottlenecks.

NOVA is available on GitHub:

https://github.com/NVSL/NOVA

And the paper of NOVA will appear in FAST 2016. I will also give a
talk in the Vault conference.

I'm also interested in any NVM/DAX related topics. Thank you.

Thanks,
Andiry

Re: [Lsf-pc] [LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[Jan Kara]

  Hi,

On Tue 09-02-16 22:15:00, Andiry Xu wrote:
> I would like to attend LSF/MM to present a new file system design for
> non-volatile main memories.

Well, LSF/MM is based more on discussions than presentations. Also a lot of
people from LSF/MM will go to Vault so I don't think presenting at LSF/MM
would make much sense. But we register your attend request.

								Honza

> The goal of NOVA is to provide high performance and strong consistency
> (atomic metadata, data, mmap updates) at the same time.
> 
> Although NOVA is a LFS, as it targets a different memory technology,
> it looks very different from conventional LFS. Some of the key design
> decisions of NOVA include:
> 
> Per-inode log: Each inode has a log, with tail pointer points to the
> latest committed entry. This allows for high concurrency and parallel
> log scanning.
> 
> Log is a linked list: Allows for fine-grained, page-size granularity
> garbage collection. Also, allocating log space is easy since NOVA does
> not need to allocate large, contiguous space for logs.
> 
> Cheap atomicity: To atomically append a log, NOVA simply appends the
> log entry and then updates the log tail pointer. To coordinate updates
> across logs, NOVA appends each log and journal the log tails to update
> all logs atomically. This mechanism has lower overhead than journaling
> (which doubles writes) and shadow paging (which causes cascade
> updates).
> 
> Stores file data outside the log: NOVA appends metadata of writes to
> the log and handles file data in a copy-on-write way. This results in
> a shorter log, and garbage collection is simple and efficient, as NOVA
> never copies data in log cleaning.
> 
> Highly scalable: NOVA has free list, journal and inode table at each
> CPU to avoid global locking and scalability bottlenecks.
> 
> NOVA is available on GitHub:
> 
> https://github.com/NVSL/NOVA
> 
> And the paper of NOVA will appear in FAST 2016. I will also give a
> talk in the Vault conference.
> 
> I'm also interested in any NVM/DAX related topics. Thank you.
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [Lsf-pc] [LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[Andiry Xu]

On Wed, Feb 10, 2016 at 3:14 AM, Jan Kara <jack@suse.cz> wrote:
>   Hi,
>
> On Tue 09-02-16 22:15:00, Andiry Xu wrote:
>> I would like to attend LSF/MM to present a new file system design for
>> non-volatile main memories.
>
> Well, LSF/MM is based more on discussions than presentations. Also a lot of
> people from LSF/MM will go to Vault so I don't think presenting at LSF/MM
> would make much sense. But we register your attend request.
>
>                                                                 Honza
>

Thank you Jan.


>> The goal of NOVA is to provide high performance and strong consistency
>> (atomic metadata, data, mmap updates) at the same time.
>>
>> Although NOVA is a LFS, as it targets a different memory technology,
>> it looks very different from conventional LFS. Some of the key design
>> decisions of NOVA include:
>>
>> Per-inode log: Each inode has a log, with tail pointer points to the
>> latest committed entry. This allows for high concurrency and parallel
>> log scanning.
>>
>> Log is a linked list: Allows for fine-grained, page-size granularity
>> garbage collection. Also, allocating log space is easy since NOVA does
>> not need to allocate large, contiguous space for logs.
>>
>> Cheap atomicity: To atomically append a log, NOVA simply appends the
>> log entry and then updates the log tail pointer. To coordinate updates
>> across logs, NOVA appends each log and journal the log tails to update
>> all logs atomically. This mechanism has lower overhead than journaling
>> (which doubles writes) and shadow paging (which causes cascade
>> updates).
>>
>> Stores file data outside the log: NOVA appends metadata of writes to
>> the log and handles file data in a copy-on-write way. This results in
>> a shorter log, and garbage collection is simple and efficient, as NOVA
>> never copies data in log cleaning.
>>
>> Highly scalable: NOVA has free list, journal and inode table at each
>> CPU to avoid global locking and scalability bottlenecks.
>>
>> NOVA is available on GitHub:
>>
>> https://github.com/NVSL/NOVA
>>
>> And the paper of NOVA will appear in FAST 2016. I will also give a
>> talk in the Vault conference.
>>
>> I'm also interested in any NVM/DAX related topics. Thank you.
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR

Re: [Lsf-pc] [LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[James Bottomley]

[cc list cut to pc only]
On Wed, 2016-02-10 at 12:14 +0100, Jan Kara wrote:
>   Hi,
> 
> On Tue 09-02-16 22:15:00, Andiry Xu wrote:
> > I would like to attend LSF/MM to present a new file system design 
> > for non-volatile main memories.
> 
> Well, LSF/MM is based more on discussions than presentations. Also a 
> lot of people from LSF/MM will go to Vault so I don't think 
> presenting at LSF/MM would make much sense. But we register your
> attend request.

What's this "we" business?  Hannes added one name (Vladimir Davydov)
since I went off to do some patent litigation assistance on 4 Feb.  It
looks like we've quite a big backlog that I'm just adding now. 
 However, someone else doing it while I was away would have been
appreciated.  Even if I add the rest, we still need people to go over
the list and check I didn't miss anything.  People reply in strange
ways and our audience is apt not to kick up a fuss until they don't get
their invitation...

Thanks,

James

Re: [Lsf-pc] [LSF/MM ATTEND] [LSF/MM TOPIC] NOVA: A log-structured file system for NVM

[Jan Kara]

On Wed 10-02-16 08:19:56, James Bottomley wrote:
> [cc list cut to pc only]
> On Wed, 2016-02-10 at 12:14 +0100, Jan Kara wrote:
> >   Hi,
> > 
> > On Tue 09-02-16 22:15:00, Andiry Xu wrote:
> > > I would like to attend LSF/MM to present a new file system design 
> > > for non-volatile main memories.
> > 
> > Well, LSF/MM is based more on discussions than presentations. Also a 
> > lot of people from LSF/MM will go to Vault so I don't think 
> > presenting at LSF/MM would make much sense. But we register your
> > attend request.
> 
> What's this "we" business?  Hannes added one name (Vladimir Davydov)
> since I went off to do some patent litigation assistance on 4 Feb.  It
> looks like we've quite a big backlog that I'm just adding now. 
>  However, someone else doing it while I was away would have been
> appreciated.  Even if I add the rest, we still need people to go over
> the list and check I didn't miss anything.  People reply in strange
> ways and our audience is apt not to kick up a fuss until they don't get
> their invitation...

I went through my LSF mailbox and filled in two missing people (Eric Sandeen
and Coly Li). I've pinged David Woodhouse whether he wants to attend or not
since he stated he wants but never sent an official request.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR