Re: SDD I/O very low < 10% normal
On 21/09/14 07:08 PM, Steve Litt wrote:
>
> Hi KS,
>
> Over time, SSD's get, for want of a better word, fragmented. Especially
> if they endure a lot of writes.
>
> Many times, this "fragmentation" can be corrected. See this:
>
> https://sites.google.com/site/lightrush/random-1/howtoconfigureext4toenabletrimforssdsonubuntu
>
> HTH,
>
> SteveT
>
Thanks for the pointer. I had run fstrim manually during my initial
troubleshooting but it didn't make any noticeable difference.
$> sudo fstrim -v /virtual/
I have rebooted the machine and checked the BIOS - it says that is set
to UDMA6 (same as the Intel drive). Also, checked that the motherboard
(M4A89GTD PRO/USB) has all SATA ports supporting SATA 3.0.
But after reboot the settings seems to have been changed by the BIOS -
(haven't checked VM performance though):
$> sudo hdparm -tT /dev/sdd
/dev/sdd:
Timing cached reads: 8178 MB in 2.00 seconds = 4089.75 MB/sec
Timing buffered disk reads: 930 MB in 3.01 seconds = 309.33 MB/sec
sudo hdparm -i /dev/sdd
/dev/sdd:
Model=KINGSTON SV300S37A240G, FwRev=520ABBF0, SerialNo=
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=468862128
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 *udma2 udma3 udma4 udma5 udma6
AdvancedPM=yes: unknown setting WriteCache=enabled
Drive conforms to: unknown: ATA/ATAPI-2,3,4,5,6,7
* signifies the current active mode
The hdparm shows much normal buffered disk reads (although only 75% of
the Intel) but would this setting stick during reboots?
KS
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