# zfs , adding a usb hard drive to a zpool



## wonslung (May 31, 2009)

is there any problems adding a usb hard drive to a zpool?

will the system continue to boot properely if you have 2 sata drives and one usb hard drive in a zpool?
i can't find any info on this


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## hedwards (Jun 3, 2009)

Well, probably the big problem would be making sure that the disk was given a consistent dev each time and boot. Other than that, the only thing I can think of is that that interface being slower than what SATA provides would slow the entire process down.

I've been experimenting with the glabel, but so far I've had mixed results, I can label them after boot, but the labels get removed during boot. From what I can tell 7.2 and earlier don't support labels for zfs partitions.


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## phoenix (Jun 3, 2009)

I thought glabel was for labelling *devices* whereas tunefs was for labelling *filessystems*.  Does glabel support labelling of filesystems (or partitions) as well?  Reading of the man page shows glabel to only support creation of device labels.  Filesystem/partition labels can be read by glabel, but can only be created by the fs tools themselves.

There are two ways to call glabel:  one creates a temporary label that is removed during boot; the other creates a permanent label that stored in the last sector(s) of the device.

This creates a temp label that only lasts until the next boot:
`# glabel create mydevice /path/to/device`

This create a permanent label that is stored on the device:
`# glabel label mydevice /path/to/device`


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## abatie (Dec 1, 2009)

Is there a way to tell zfs to look in a particular place other than -d (which is directory only)?  I have a usb sata docking station.  I put in a disk exported from an opensolaris system and do "zpool import offsite" and it says:


```
$ zpool import -d /dev offsite
cannot import 'offsite': no such pool available
```

The drive is seen as da0, though it does complain "GEOM: da0: corrupt of invalid GPT detected." and "GPT rejected".  I'm assuming that's because GEOM doesn't recognize a zfs partition.  

zfs also complains about kernel memory being too small, but all I want to do is copy some backup files off to a file server, won't be stressing it at all...


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## fronclynne (Dec 2, 2009)

phoenix said:
			
		

> I thought glabel was for labelling *devices* whereas tunefs was for labelling *filessystems*.  Does glabel support labelling of filesystems (or partitions) as well?  Reading of the man page shows glabel to only support creation of device labels.  Filesystem/partition labels can be read by glabel, but can only be created by the fs tools themselves.
> 
> There are two ways to call glabel:  one creates a temporary label that is removed during boot; the other creates a permanent label that stored in the last sector(s) of the device.
> 
> ...



It's been a while, but it is my understanding that glabel'd objects (if I may be so bold as to co-opt that term) may be used pretty much as one wishes (newfs'd, bsdlabel'd, added to other geom objects) but glabels are not easily added to extant, newfs'd filesystems, which is what the whole tunefs label is all about.

I know in the past that I have sliced & then partitioned, & *then* used glabel on the partitions (& subsequently used said labels under /etc/fstab) (albeit I use /dev/ufsid/beefbeef0beef stuff right now & all those old systems are dead & gone, like summer breeze or massengill).

Oh, my swap is currently a glabel of /dev/ad4s1b . . . if that matters.

(am I speaking clearly through all this gin?  I honestly can't tell if all of that makes sense or not.  I can stop any time, you know)


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