one more load-cycle-count problem

[Gerrit Kühn]

Hi all,

After being disturbed by the firmware issues of the wd drives causing
exceeding load cycles (see thread "immense delayed write to file system
(ZFS and UFS2), performance issues" in January), I have found some more
problematic drives in the following setup:

4 x 2.5" WDC WD4000BEVT-00ZAT0 in RAIDZ1 configuration attached to a
Supermicro SAS controller:

mpt0 at pci0:2:0:0:        class=0x010000 card=0xa38015d9 chip=0x00581000
rev=0x08 hdr=0x00 vendor     = 'LSI Logic (Was: Symbios Logic, NCR)'
    device     = 'SAS 3000 series, 8-port with 1068E -StorPort'
    class      = mass storage
    subclass   = SCSI

luna# camcontrol devlist
<ATA WDC WD4000BEVT-0 1A01>        at scbus0 target 0 lun 0 (pass0,da0)
<ATA WDC WD4000BEVT-0 1A01>        at scbus0 target 1 lun 0 (pass1,da1)
<ATA WDC WD4000BEVT-0 1A01>        at scbus0 target 2 lun 0 (pass2,da2)
<ATA WDC WD4000BEVT-0 1A01>        at scbus0 target 3 lun 0 (pass3,da3)


The disks appear to load/unload every 10s or so if I do not artificially
keep them busy. Does anyone here have a suggestion how to make this
interval longer or even turn off the unload feature completely?

I tried

luna# camcontrol idle da0 -t 600
(pass0:mpt0:0:0:0): CMD: IDLE: e3 00 00 00 00 40 00 00 00 00 78 00
(pass0:mpt0:0:0:0): CAM Status: CCB request was invalid

luna# camcontrol standby da0 -t 600
(pass0:mpt0:0:0:0): CMD: STANDBY: e2 00 00 00 00 40 00 00 00 00 78 00
(pass0:mpt0:0:0:0): CAM Status: CCB request was invalid


>From /usr/share/misc/scsi_modes I gather that page 26 should contain power
control features, but no avail:

luna# camcontrol modepage da0 -m 26
camcontrol: error sending mode sense command


Any further ideas how to get rid of this "feature"?


cu
  Gerrit