We already have this specified. This specific /dev/sdn device is just
receiving half the load compared to others across all our caches.
On Sun, Mar 27, 2016 at 2:01 PM, Schmerge, John (Contractor) <
John_Schmerge@cable.comcast.com> wrote:
> Hi Steve,
>
>
> Try adding a "volume=X" to each line of your storage.config. There's an
> old issue with ATS when you have a single volume and replace a drive, in
> which it (silently) does not use it because because it cannot figure out
> which volume the drive belongs to. Explicitly assigning the volume in
> storage.config sidesteps this condition.
>
>
> -John
>
>
> ------------------------------
> *From:* Steve Malenfant <smalenfant@gmail.com>
> *Sent:* Saturday, March 26, 2016 10:29 PM
> *To:* users@trafficserver.apache.org
> *Subject:* ATS Disk load distribution
>
> Hi,
>
> Our servers have 24 cache disks. On each of them, I'm seing an unusual
> pattern where the 14th cache disk (/dev/sdn here) has half the tps and
> Blk_read of the others while running a simple iostat.
>
> The OS drive is /dev/sdy.
>
> Is there something obvious that could explain this? Anybody else seeing
> similar behaviors?
>
> Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
> sdy 8.50 0.59 412.30 1182292 826749224
> sdb 17.96 5574.30 763.26 11177773390 1530520872
> sda 17.27 5427.78 753.80 10883976079 1511537961
> sdc 16.76 5426.23 752.01 10880866108 1507966007
> sdf 17.40 5415.19 754.99 10858730317 1513930486
> sdd 17.42 5415.10 750.04 10858548347 1504011560
> sdg 17.43 5482.40 757.33 10993500408 1518615277
> sde 16.49 5265.87 740.41 10559295722 1484695034
> sdh 17.38 5492.09 758.66 11012923059 1521284992
> sdj 18.73 5849.73 787.82 11730078650 1579772953
> sdk 16.85 5319.37 742.29 10666574619 1488471133
> sdl 17.53 5608.22 766.14 11245803256 1536281866
> sdn 8.58 2555.06 517.71 5123501157 1038125596
> sdm 17.69 5525.47 757.92 11079862986 1519798735
> sdo 15.75 5039.02 726.77 10104411633 1457343705
> sdi 18.33 5684.66 782.37 11399081848 1568839983
> sdq 17.49 5596.34 760.76 11221981240 1525498204
> sdp 16.31 5143.23 734.07 10313388901 1471978836
> sdr 16.96 5393.52 755.80 10815269418 1515562524
> sdt 16.47 5293.78 740.87 10615265266 1485622464
> sds 15.99 5201.40 732.21 10430031258 1468246477
> sdv 17.92 5684.24 779.27 11398240262 1562614587
> sdu 17.26 5504.14 760.25 11037086102 1524475490
> sdx 17.74 5580.22 762.95 11189655745 1529890237
> sdw 17.17 5308.27 744.56 10644334189 1493013627
>
> Steve
>
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