freebsd stable - Dec 2010 - ZFS - moving from a zraid1 to zraid2 pool with 1.5tb disks

Hello list,



I currently have a ZFS zraid1 with 4x 1.5TB drives.
The system is a zfs-only FreeBSD 8.1 with zfs version 14.

I am concerned that in the event a drive fails, I won't be able to
repair the disks in time before another actually fails.




I wish to reinstall the OS on a dedicated drive (possibly SSD, doesn't
matter, likely UFS) and dedicate the 1.5tb disks to storage only.

I have ordered 5x new drives and would like to create a new zraid2
mirrored pool.

Then I plan on moving data from pool1 to pool2, removing drives from
pool1 and adding them to pool2.



My questions are as follows:

With a total of 9x 1.5TB drives, should I be using zraid3 instead of
zraid2 ? I will not be able to add any more drives so unnecessary parity
drives = less storage room.

What are the steps for properly removing my drives from the zraid1 pool
and inserting them in the zraid2 pool ?


Regards,


dfl

Hi,

I think it's enough to have 2 parity drives with raidz2. If a drive fails
another two has to fail for data loss. However, keep in mind that raid (in
any form) is not instead of backups.

I have a setup where a 8TB RAID5 is the main backup and serves as file
server for not important things AND there's a 3TB RAID5 in a different
machine for secondary backups.

Regards,
Andras


On Thu, 30 Dec 2010 12:40:00 +0100, Damien Fleuriot <ml@my.gd>
wrote:
> Hello list,
> 
> 
> 
> I currently have a ZFS zraid1 with 4x 1.5TB drives.
> The system is a zfs-only FreeBSD 8.1 with zfs version 14.
> 
> I am concerned that in the event a drive fails, I won't be able to
> repair the disks in time before another actually fails.
> 
> 
> 
> 
> I wish to reinstall the OS on a dedicated drive (possibly SSD, doesn't
> matter, likely UFS) and dedicate the 1.5tb disks to storage only.
> 
> I have ordered 5x new drives and would like to create a new zraid2
> mirrored pool.
> 
> Then I plan on moving data from pool1 to pool2, removing drives from
> pool1 and adding them to pool2.
> 
> 
> 
> My questions are as follows:
> 
> With a total of 9x 1.5TB drives, should I be using zraid3 instead of
> zraid2 ? I will not be able to add any more drives so unnecessary parity
> drives = less storage room.
> 
> What are the steps for properly removing my drives from the zraid1 pool
> and inserting them in the zraid2 pool ?
> 
> 
> Regards,
> 
> 
> dfl
> 
> _______________________________________________
> freebsd-stable@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to
"freebsd-stable-unsubscribe@freebsd.org"

On Thu, 30 Dec 2010 12:40:00 +0100, Damien Fleuriot <ml@my.gd> wrote:
> Hello list,
>
>
>
> I currently have a ZFS zraid1 with 4x 1.5TB drives.
> The system is a zfs-only FreeBSD 8.1 with zfs version 14.
>
> I am concerned that in the event a drive fails, I won't be able to
> repair the disks in time before another actually fails.
>
>
>
>
> I wish to reinstall the OS on a dedicated drive (possibly SSD, doesn't
> matter, likely UFS) and dedicate the 1.5tb disks to storage only.
>
> I have ordered 5x new drives and would like to create a new zraid2
> mirrored pool.
>
> Then I plan on moving data from pool1 to pool2, removing drives from
> pool1 and adding them to pool2.
>
>
>
> My questions are as follows:
>
> With a total of 9x 1.5TB drives, should I be using zraid3 instead of
> zraid2 ? I will not be able to add any more drives so unnecessary parity
> drives = less storage room.
>
> What are the steps for properly removing my drives from the zraid1 pool
> and inserting them in the zraid2 pool ?
>
>
> Regards,
>
>
> dfl
Make sure you have spare drives so you can swap in a new one quickly and  
have off-line backups in case disaster strikes. Extra backups are always  
nice. Disks are not the only parts which can break and damage your data.

Ronald.

This is a home machine so I am afraid I won't have backups in place, if
only because I just won't have another machine with as much disk space.


The data is nothing critically important anyway, movies, music mostly.


My objective here is getting more used to ZFS and seeing how performance
gets.

I remember getting rather average performance on v14 but Jean-Yves
reported good performance boosts from upgrading to v15.

Will try this out when the disks arrive :)


Thanks for the pointers guys.

On 12/30/10 6:49 PM, Ronald Klop wrote:
> On Thu, 30 Dec 2010 12:40:00 +0100, Damien Fleuriot <ml@my.gd> wrote:
> 
>> Hello list,
>>
>>
>>
>> I currently have a ZFS zraid1 with 4x 1.5TB drives.
>> The system is a zfs-only FreeBSD 8.1 with zfs version 14.
>>
>> I am concerned that in the event a drive fails, I won't be able to
>> repair the disks in time before another actually fails.
>>
>>
>>
>>
>> I wish to reinstall the OS on a dedicated drive (possibly SSD,
doesn't
>> matter, likely UFS) and dedicate the 1.5tb disks to storage only.
>>
>> I have ordered 5x new drives and would like to create a new zraid2
>> mirrored pool.
>>
>> Then I plan on moving data from pool1 to pool2, removing drives from
>> pool1 and adding them to pool2.
>>
>>
>>
>> My questions are as follows:
>>
>> With a total of 9x 1.5TB drives, should I be using zraid3 instead of
>> zraid2 ? I will not be able to add any more drives so unnecessary
parity
>> drives = less storage room.
>>
>> What are the steps for properly removing my drives from the zraid1 pool
>> and inserting them in the zraid2 pool ?
>>
>>
>> Regards,
>>
>>
>> dfl
> 
> Make sure you have spare drives so you can swap in a new one quickly and
> have off-line backups in case disaster strikes. Extra backups are always
> nice. Disks are not the only parts which can break and damage your data.
> 
> Ronald.
> _______________________________________________
> freebsd-stable@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
> To unsubscribe, send any mail to
"freebsd-stable-unsubscribe@freebsd.org"

On 2010-Dec-30 12:40:00 +0100, Damien Fleuriot <ml@my.gd>
wrote:
>What are the steps for properly removing my drives from the zraid1 pool
>and inserting them in the zraid2 pool ?
I've documented my experiences in migrating from a 3-way RAIDZ1 to a
6-way RAIDZ2 at http://bugs.au.freebsd.org/dokuwiki/doku.php/zfsraid

Note that, even for a home system, backups are worthwhile.  In my
case, I backup onto a 2TB disk in an eSATA enclosure.  That's
currently (just) adequate but I'll soon need to identify data that I
can leave off that backup.

-- 
Peter Jeremy
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On 12/30/10 12:40, Damien Fleuriot wrote:
> I am concerned that in the event a drive fails, I won't be able to
> repair the disks in time before another actually fails.
An old trick to avoid that is to buy drives from different series or 
manufacturers (the theory is that identical drives tend to fail at the 
same time), but this may not be applicable if you have 5 drives in a 
volume :) Still, you can try playing with RAIDZ levels and probabilities.