file systems

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file systems

Friedrich Locke
Hi folks,

does anybody here run OBSD with a file system bigger than 10TB ?
How much time boot takes to bring the system up (i mean fsck) ?
Are you using ffs2 ? With softdep ?

Thanks.
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Re: file systems

Peter Hessler
On 2017 May 26 (Fri) at 11:35:49 -0300 (-0300), Friedrich Locke wrote:
:Hi folks,
:
:does anybody here run OBSD with a file system bigger than 10TB ?
:How much time boot takes to bring the system up (i mean fsck) ?
:Are you using ffs2 ? With softdep ?
:
:Thanks.

I created a 24T disk with ff2.  I populated 2Tb of it while in async
mode, then pulled the power.  fsck took only 5 minutes.

Later, I repartitioned the machine to the sizes we actually want
(several 5T partitions) and it is running as ftp.hostserver.de.  We
aren't using softdep, and generally run RO on many of the partitions.

Please give it a try on your own hardware, paritition sizes, and
collection of files.

--
Don't say "yes" until I finish talking.
                -- Darryl F. Zanuck

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Re: file systems

quisquous
I've got a 27T drive, single partition, about half full. Combination of
big files and lots of small ones. 32G of ECC RAM. Hardware RAID5 ATM
though I've used software RAID5 on the same array and that was good too.  
I keep offline backups of everything. I think it takes around an hour to
fsck, but I haven't timed it. Not using softdep. Not RO. Not sure what
the file system is, whatever newfs chose...disklabel says fstype is
4.2BSD.

On 05/26, Peter Hessler wrote:

>On 2017 May 26 (Fri) at 11:35:49 -0300 (-0300), Friedrich Locke wrote:
>:Hi folks,
>:
>:does anybody here run OBSD with a file system bigger than 10TB ?
>:How much time boot takes to bring the system up (i mean fsck) ?
>:Are you using ffs2 ? With softdep ?
>:
>:Thanks.
>
>I created a 24T disk with ff2.  I populated 2Tb of it while in async
>mode, then pulled the power.  fsck took only 5 minutes.
>
>Later, I repartitioned the machine to the sizes we actually want
>(several 5T partitions) and it is running as ftp.hostserver.de.  We
>aren't using softdep, and generally run RO on many of the partitions.
>
>Please give it a try on your own hardware, paritition sizes, and
>collection of files.
>
>--
>Don't say "yes" until I finish talking.
> -- Darryl F. Zanuck
>

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Re: file systems

Steven McDonald
In reply to this post by Friedrich Locke
On Fri, 26 May 2017 11:35:49 -0300
Friedrich Locke <[hidden email]> wrote:

> Hi folks,
>
> does anybody here run OBSD with a file system bigger than 10TB ?
> How much time boot takes to bring the system up (i mean fsck) ?
> Are you using ffs2 ? With softdep ?
>
> Thanks.

This depends heavily on how you plan to use the filesystem. I have an 8
TB filesystem (FFS2 with softdep) that takes several hours to fsck,
mostly in phase 2 ("Check Pathnames") because of a very large number of
hard links.

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Re: file systems

Christer Solskogen-3
In reply to this post by quisquous
One 27T drive?!


On May 26, 2017 17:27, "Scott Bonds" <[hidden email]> wrote:

> I've got a 27T drive, single partition, about half full. Combination of
> big files and lots of small ones. 32G of ECC RAM. Hardware RAID5 ATM though
> I've used software RAID5 on the same array and that was good too.  I keep
> offline backups of everything. I think it takes around an hour to fsck, but
> I haven't timed it. Not using softdep. Not RO. Not sure what the file
> system is, whatever newfs chose...disklabel says fstype is 4.2BSD.
>
> On 05/26, Peter Hessler wrote:
>
>> On 2017 May 26 (Fri) at 11:35:49 -0300 (-0300), Friedrich Locke wrote:
>> :Hi folks,
>> :
>> :does anybody here run OBSD with a file system bigger than 10TB ?
>> :How much time boot takes to bring the system up (i mean fsck) ?
>> :Are you using ffs2 ? With softdep ?
>> :
>> :Thanks.
>>
>> I created a 24T disk with ff2.  I populated 2Tb of it while in async
>> mode, then pulled the power.  fsck took only 5 minutes.
>>
>> Later, I repartitioned the machine to the sizes we actually want
>> (several 5T partitions) and it is running as ftp.hostserver.de.  We
>> aren't using softdep, and generally run RO on many of the partitions.
>>
>> Please give it a try on your own hardware, paritition sizes, and
>> collection of files.
>>
>> --
>> Don't say "yes" until I finish talking.
>>                 -- Darryl F. Zanuck
>>
>>
>
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Re: file systems

Nick Holland
In reply to this post by Friedrich Locke
On 05/26/17 10:35, Friedrich Locke wrote:
> Hi folks,
>
> does anybody here run OBSD with a file system bigger than 10TB ?
> How much time boot takes to bring the system up (i mean fsck) ?
> Are you using ffs2 ? With softdep ?
>
> Thanks.

Error #1: assuming someone else's experience will have anything at all
to do with yours.  When doing things like this, you need to just test it
yourself with your data and see what happens.  And as I always preach,
"testing" doesn't stop at "I built it and it works!"  Experiment with
failure modes, look at how you move data to a new machine when you need
to, etc.  Your performance will depend greatly on your hw and your data.

Error #2: When you create a single file system that big, you are usually
Doing it Wrong (or at least, sub-optimally).  You really should be
"chunking" your data into more manageable chunks if at all possible.

Some of the benefits to "chunking" your data:
* If you can RO "full" file systems, your fsck time drops to zero for those.
* You buy storage when you need it instead of in advance.  Since storage
almost always gets bigger and cheaper, delaying storage purchase makes a
lot of sense.
* Even with modern hw, a gigabyte of data takes a while to move.  A
terabyte takes a long time to move.
* Someday, you will need to upgrade/replace the hardware.  Chunking your
data gives lots of options here, which might be the difference in doing
a hw replacement/upgrade in a routine hw maintenance window vs. spending
a very long weekend down.
* When something bad happens, you may spend a lot less time recreating
your data.

Nick.