zfs discuss - Jul 2006 - ZFS support for USB disks 120GB Western Digital

Hey,

I have a portable harddisk Western Digital 120GB USB. Im running Nevada b42a on
Thinkpad T43. Is this a supported configuration for setting up ZFS on portable
disks ?

Found out some old blogs about this topic:
http://blogs.sun.com/roller/page/artem?entry=zfs_on_the_go and some other info
under: http://www.sun.com/io_technologies/USB-Faq.html

Is this information still valid ? Under ZFS FAQ there is no mention of this
topic, a good idea is to add a section about ZFS on mobile devices.

Thanks,
Stefan

# rmformat
Looking for devices...
     1. Volmgt Node: /vol/dev/aliases/cdrom0
        Logical Node: /dev/rdsk/c1t0d0s2
        Physical Node: /pci at 0,0/pci-ide at 1f,2/ide at 1/sd at 0,0
        Connected Device: MATSHITA UJDA765 DVD/CDRW 1.70
        Device Type: DVD Reader
        Bus: IDE
        Size: <Unknown>
        Label: <Unknown>
        Access permissions: <Unknown>
     2. Volmgt Node: /vol/dev/aliases/rmdisk0
        Logical Node: /dev/rdsk/c2t0d0p0
        Physical Node: /pci at 0,0/pci1014,566 at 1d,7/hub at 1/storage at
4/disk at 0,0
        Connected Device: WDC WD12 00VE-00KWT0      0000
        Device Type: Removable
        Bus: USB
        Size: 114.5 GB
        Label: <None>
        Access permissions: Medium is not write protected.
 
 
This message posted from opensolaris.org

We don''t have a specific supported configuration method for usb  
devices for ZFS.  Most people are using them as mirrors or backups  
for their laptop data.  It''s really up to you. There are a few  
threads from the discuss archives where people have discussed some  
different possible configs for usb storage or ways they''ve used it.   
One is here:

http://www.opensolaris.org/jive/thread.jspa?messageID=25144&#25144

where David Bustos also mentions Artem''s blog as a go to.  Perhaps we  
also should add something to this effect in the FAQ....

Also, depending on how you intend to use the disk, a known issue is  
this:
6424510 usb ignores DKIOCFLUSHWRITECACHE



Noel

On Jul 18, 2006, at 11:53 PM, Stefan Parvu wrote:
> Hey,
>
> I have a portable harddisk Western Digital 120GB USB. Im running  
> Nevada b42a on Thinkpad T43. Is this a supported configuration for  
> setting up ZFS on portable disks ?
>
> Found out some old blogs about this topic:
> http://blogs.sun.com/roller/page/artem?entry=zfs_on_the_go and some  
> other info under: http://www.sun.com/io_technologies/USB-Faq.html
>
> Is this information still valid ? Under ZFS FAQ there is no mention  
> of this topic, a good idea is to add a section about ZFS on mobile  
> devices.
>
> Thanks,
> Stefan
>
> # rmformat
> Looking for devices...
>      1. Volmgt Node: /vol/dev/aliases/cdrom0
>         Logical Node: /dev/rdsk/c1t0d0s2
>         Physical Node: /pci at 0,0/pci-ide at 1f,2/ide at 1/sd at 0,0
>         Connected Device: MATSHITA UJDA765 DVD/CDRW 1.70
>         Device Type: DVD Reader
>         Bus: IDE
>         Size: <Unknown>
>         Label: <Unknown>
>         Access permissions: <Unknown>
>      2. Volmgt Node: /vol/dev/aliases/rmdisk0
>         Logical Node: /dev/rdsk/c2t0d0p0
>         Physical Node: /pci at 0,0/pci1014,566 at 1d,7/hub at 1/storage at
4/
> disk at 0,0
>         Connected Device: WDC WD12 00VE-00KWT0      0000
>         Device Type: Removable
>         Bus: USB
>         Size: 114.5 GB
>         Label: <None>
>         Access permissions: Medium is not write protected.
>
>
> This message posted from opensolaris.org
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

I''ve updated the blog entry, no hacking around is necessary anymore.
''svcadm
disable volfs'' is still recommended (vold/volfs will be completely
removed
soon). USB is just an interface board slapped on the disk, there are disks with 
both USB and SATA interfaces - you can connect with either cable and it
won''t
make a difference to ZFS because it tracks disks by devid, not device name.

So what you do with your disks is really up to you. If you just want a 
single-disk zpool (though ZFS doesn''t favor that), then probably
''zpool export''
before disconnecting and ''zpool import'' after connecting will
do it for you.

-Artem.

Noel Dellofano wrote:
> We don''t have a specific supported configuration method for usb
devices
> for ZFS.  Most people are using them as mirrors or backups for their 
> laptop data.  It''s really up to you. There are a few threads from
the
> discuss archives where people have discussed some different possible 
> configs for usb storage or ways they''ve used it.  One is here:
> 
> http://www.opensolaris.org/jive/thread.jspa?messageID=25144&#25144
> 
> where David Bustos also mentions Artem''s blog as a go to.  Perhaps
we
> also should add something to this effect in the FAQ....
> 
> Also, depending on how you intend to use the disk, a known issue is this:
> 6424510 usb ignores DKIOCFLUSHWRITECACHE
> 
> 
> 
> Noel
> 
> On Jul 18, 2006, at 11:53 PM, Stefan Parvu wrote:
> 
>> Hey,
>>
>> I have a portable harddisk Western Digital 120GB USB. Im running 
>> Nevada b42a on Thinkpad T43. Is this a supported configuration for 
>> setting up ZFS on portable disks ?
>>
>> Found out some old blogs about this topic:
>> http://blogs.sun.com/roller/page/artem?entry=zfs_on_the_go and some 
>> other info under: http://www.sun.com/io_technologies/USB-Faq.html
>>
>> Is this information still valid ? Under ZFS FAQ there is no mention of 
>> this topic, a good idea is to add a section about ZFS on mobile
devices.
>>
>> Thanks,
>> Stefan
>>
>> # rmformat
>> Looking for devices...
>>      1. Volmgt Node: /vol/dev/aliases/cdrom0
>>         Logical Node: /dev/rdsk/c1t0d0s2
>>         Physical Node: /pci at 0,0/pci-ide at 1f,2/ide at 1/sd at 0,0
>>         Connected Device: MATSHITA UJDA765 DVD/CDRW 1.70
>>         Device Type: DVD Reader
>>         Bus: IDE
>>         Size: <Unknown>
>>         Label: <Unknown>
>>         Access permissions: <Unknown>
>>      2. Volmgt Node: /vol/dev/aliases/rmdisk0
>>         Logical Node: /dev/rdsk/c2t0d0p0
>>         Physical Node: /pci at 0,0/pci1014,566 at 1d,7/hub at 1/storage
at 4/disk at 0,0
>>         Connected Device: WDC WD12 00VE-00KWT0      0000
>>         Device Type: Removable
>>         Bus: USB
>>         Size: 114.5 GB
>>         Label: <None>
>>         Access permissions: Medium is not write protected.
>>
>>
>> This message posted from opensolaris.org
>> _______________________________________________
>> zfs-discuss mailing list
>> zfs-discuss at opensolaris.org
>> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
> 
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Hello Artem,

Thursday, July 20, 2006, 12:37:06 AM, you wrote:

AK> I''ve updated the blog entry, no hacking around is necessary
anymore. ''svcadm
AK> disable volfs'' is still recommended (vold/volfs will be
completely removed
AK> soon). USB is just an interface board slapped on the disk, there are
disks with
AK> both USB and SATA interfaces - you can connect with either cable and it
won''t
AK> make a difference to ZFS because it tracks disks by devid, not device
name.

AK> So what you do with your disks is really up to you. If you just want a
AK> single-disk zpool (though ZFS doesn''t favor that), then probably
''zpool export''
AK> before disconnecting and ''zpool import'' after
connecting will do it for you.

If you won''t do it (zpool export) it will end-up probably with a
system panic right now.

-- 
Best regards,
 Robert                            mailto:rmilkowski at task.gda.pl
                                       http://milek.blogspot.com