On Feb 1, 2012, at 8:07 PM, Bob Friesenhahn wrote:
> On Wed, 1 Feb 2012, Jan Hellevik wrote:
>>>
>>> Are all of the disks the same make and model?
>>
>> They are different makes - I try to make pairs of different brands to
>> minimise risk.
>
> Does your pairing maintain the same pattern of disk type across all the
> pairings?
>
Not 100% percent sure I understand what you mean (english is not my first
language).
These are the disks:
mirror-0: wd15ears + hd154ui
mirror-1: wd15ears + hd154ui
mirror-2: wd20ears + hd204ui
Two pairs of 1.5TB and one pair of 2.0TB. I would like to have pairs of the
same size, but these were the disks I had available, and since it is a backup
pool I do not think it matters that much. If the flooding hadn't tripled the
price of disks I would probably buy a few more, but not with the current price
level. :-(
I am waiting for a replacement 1.5TB disk and will replace the 'bad' one as
soon as I get it.
> Some modern disks use 4k sectors while others still use 512 bytes. If the
> slow disk is a 4k sector model but the others are 512 byte models, then that
> would certainly explain a difference.
>
AVAILABLE DISK SELECTIONS:
0. c5d0 <?????xH?????????????0?0"??? cyl 14590 alt 2 hd 255 sec 63>
1. c5d1 <?????xH?????????????0?0"??? cyl 14590 alt 2 hd 255 sec 63>
2. c6t66d0 <ATA-WDC WD15EARS-00Z-0A80-1.36TB>
3. c6t67d0 <ATA-SAMSUNG HD501LJ-0-12-465.76GB>
4. c6t68d0 <ATA-WDC WD6400AAKS-2-3B01-596.17GB>
5. c6t69d0 <ATA-SAMSUNG HD501LJ-0-12-465.76GB>
6. c6t70d0 <ATA-WDC WD15EARS-00Z-0A80-1.36TB>
7. c6t71d0 <ATA-SAMSUNG HD501LJ-0-13-465.76GB>
8. c6t72d0 <ATA -WDC WD6400AAKS--3B01 cyl 38909 alt 2 hd 255 sec 126>
9. c6t73d0 <ATA-SAMSUNG HD501LJ-0-13-465.76GB>
10. c6t74d0 <ATA-SAMSUNG HD154UI-1118-1.36TB>
11. c6t75d0 <ATA-SAMSUNG HD501LJ-0-11-465.76GB>
12. c6t76d0 <ATA-SAMSUNG HD204UI-0001-1.82TB>
13. c6t77d0 <ATA-SAMSUNG HD501LJ-0-11-465.76GB>
14. c6t78d0 <ATA-SAMSUNG HD154UI-1118-1.36TB>
15. c6t79d0 <ATA-SAMSUNG HD501LJ-0-11-465.76GB>
16. c6t80d0 <ATA-WDC WD20EARS-00M-AB51-1.82TB>
17. c6t81d0 <ATA-SAMSUNG HD501LJ-0-11-465.76GB>
mirror-0
2. c6t66d0 <ATA-WDC WD15EARS-00Z-0A80-1.36TB>
14. c6t78d0 <ATA-SAMSUNG HD154UI-1118-1.36TB>
mirror-1
6. c6t70d0 <ATA-WDC WD15EARS-00Z-0A80-1.36TB>
10. c6t74d0 <ATA-SAMSUNG HD154UI-1118-1.36TB>
mirror-2
12. c6t76d0 <ATA-SAMSUNG HD204UI-0001-1.82TB>
16. c6t80d0 <ATA-WDC WD20EARS-00M-AB51-1.82TB>
You can see that mirror-0 and mirror-1 have identical disk pairs.
BTW: Can someone explain why this:
8. c6t72d0 <ATA -WDC WD6400AAKS--3B01 cyl 38909 alt 2 hd 255 sec 126>
is not shown the same way as this:
4. c6t68d0 <ATA-WDC WD6400AAKS-2-3B01-596.17GB>
Why the cylinder/sector in line 8?
> Assuming that a couple of your disks are still unused, you could try
> replacing the suspect drive with an unused drive (via zfs command) to see if
> the slowness goes away. You could also make that vdev a triple-mirror since
> it is very easy to add/remove drives from a mirror vdev. Just make sure that
> your zfs syntax is correct so that you don't accidentally add a single-drive
> vdev to the pool (oops!). These sorts of things can be tested with zfs
> commands without physically moving/removing drives or endangering your data.
>
If I had available disks, I would. As of now, the are all busy. :-)
Thanks for the advice!
> Bob
> --
> Bob Friesenhahn
> bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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