#84 — Formatting output zpool iostat-v

State	Resolved
Version:	0.6.9
Area	User interface
Issue type	Bug
Severity	Medium
Submitted by	Горлов Максим
Submitted on	Sep 03, 2010
Responsible	Seth Heeren
Target release:	—

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Last modified on Sep 19, 2010 by Seth Heeren

If the pool does not use the device /dev/sd*, but uses the device /dev/disk/by-id/..., then the `zpool iostat -v` few careless

<pre>
storage / # zpool iostat -v
                                           capacity operations bandwidth
pool alloc free read write read write
-------------------------------------- ----- ----- ----- ----- ----- -----
storage 924G 2,73T 0 3 49,8K 174K
  disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56176867 231G 700G 0 0 12,6K 32,3K
  disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56216934 231G 700G 0 0 12,4K 32,6K
  disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56438569 231G 700G 0 0 12,5K 32,4K
  disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56670844 231G 700G 0 0 12,4K 32,7K
  disk/by-id/scsi-SATA_FUJITSU_MPC3032_05073571 904K 3,01G 0 0 4 43,9K
cache - - - - - -
  disk/by-id/scsi-SATA_SAMSUNG_SV0411NS01RJ10X980875 7,34G 30,0G 2 0 41,7K 43,8K
  disk/by-id/scsi-SATA_ST340810A_3FB13Y0W 7,36G 29,9G 2 0 38,6K 43,9K
  mtdblock0 7,71M 99,8M 3 1 38,3K 4,77K
-------------------------------------- ----- ----- ----- ----- ----- -----
</pre>

Steps to reproduce:: Just create pool onto /dev/disk/by-id/... links and try `zpool iostat -v`

Added by Горлов Максим on Sep 03, 2010 07:14 PM

sorry, formatting wrong :(
Please see attached file for `zpool iostat -v` output

Attached:

out.txt — Plain Text, 1Kb

Added by Seth Heeren on Sep 04, 2010 05:53 AM

Responsible manager: (UNASSIGNED) → sgheeren

Hi Maxim, Thanks for reporting to the tracker!
I'm not completely sure what it is you are reporting. I think the following FAQ entry may help you:

http://zfs-fuse.net/documentation/upgrading/pool-discovery

So using zpool import -d /dev/ may help you; but please beware of the fact that /dev/disk/by-id is recommended for various reasons mentioned in the FAQ

I can see from the pool layout that you are probably quite experienced with ZFS, so I assume you know that ZFS on Solaris has precisely the same formatting quirks, not only with zpool status, but with zpool and zfs list as well. For zfs list, -H can be used to get machine-readable output. For zpool status, I'm not sure how to make things better, but I'd assume that parsing would never be too difficult, as long as the device names don't have spaces in the names...

If you want to have the best of all worlds, you can perhaps create symlinks somewhere, like

mkdir -pv /zblk
ln -sfv /disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56176867 /zblk/1
ln -sfv /disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56216934 /zblk/2
ln -sfv /disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56438569 /zblk/3
ln -sfv /disk/by-id/scsi-SATA_WDC_WD10EARS-00_WD-WCAV56670844 /zblk/4

and then use zpool import -d /zblk to import your pool

$0.02
PS. How's your experience with the EARS disks? I just dropped 2 WD15EARS in my Solaris NAS and was wondering whether performance is OK when mixing with the EADS variety in one pool :)

Added by Seth Heeren on Sep 19, 2010 06:46 PM

Issue state: unconfirmed → resolved

proposing to close.

for the record, my (consciously, to avoid having mirrors with both disks failing around the same time) mixed EARS+EADS pools both work smoothly without noticable perf issues

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#84 — Formatting output zpool iostat-v