[linux-lvm] huge performance problems 25kb/s write speed
Cristian Livadaru
cristian at livadaru.net
Sun Sep 10 15:14:10 UTC 2006
I just rebooted with kernel 2.4 instead of 2.6
Now I have a slightly better performance. 3.6mb/s but this still
isn't optimal.
On Sep 10, 2006, at 4:25 PM, Cristian Livadaru wrote:
> I have since yesterday huge performance problems on my LVM!
> I have 2x 300GB as 1 unstriped LVM.
>
> dd if=/dev/zero of=dd.txt count=500
> 500+0 records in
> 500+0 records out
> 256000 bytes transferred in 9.999764 seconds (25601 bytes/sec)
>
> dd if=/dev/zero of=dd.txt count=500 bs=4096
> 500+0 records in
> 500+0 records out
> 2048000 bytes transferred in 10.020213 seconds (204387 bytes/sec)
>
> After a reboot it worked normal again for a while, now I have the
> same problem again.
>
> esplendidos:~# pvs
> PV VG Fmt Attr PSize PFree
> /dev/hde1 sharevg lvm2 a- 279.45G 0
> /dev/hdg1 sharevg lvm2 a- 279.45G 4.00M
>
> esplendidos:~# lvs
> LV VG Attr LSize Origin Snap% Move Copy%
> sharelv sharevg -wi-ao 558.90G
>
> esplendidos:~# vgs
> VG #PV #LV #SN Attr VSize VFree
> sharevg 2 1 0 wz--n 558.91G 4.00M
>
>
> --- Volume group ---
> VG Name sharevg
> System ID
> Format lvm2
> Metadata Areas 2
> Metadata Sequence No 2
> VG Access read/write
> VG Status resizable
> MAX LV 0
> Cur LV 1
> Open LV 1
> Max PV 0
> Cur PV 2
> Act PV 2
> VG Size 558.91 GB
> PE Size 4.00 MB
> Total PE 143080
> Alloc PE / Size 143079 / 558.90 GB
> Free PE / Size 1 / 4.00 MB
> VG UUID LaGWNF-9Ace-li4f-h8z2-SJYk-YeyB-joXznp
>
>
> --- Logical volume ---
> LV Name /dev/sharevg/sharelv
> VG Name sharevg
> LV UUID zCe6sI-pglI-7yh1-EnL4-gsKo-FOEb-POyVoL
> LV Write Access read/write
> LV Status available
> # open 1
> LV Size 558.90 GB
> Current LE 143079
> Segments 2
> Allocation inherit
> Read ahead sectors 0
> Block device 253:8
>
> --- Physical volume ---
> PV Name /dev/hde1
> VG Name sharevg
> PV Size 279.45 GB / not usable 0
> Allocatable yes (but full)
> PE Size (KByte) 4096
> Total PE 71540
> Free PE 0
> Allocated PE 71540
> PV UUID g3jfAR-Z2Ka-SCgr-08QB-8WBn-5g4h-jXLrn1
>
> --- Physical volume ---
> PV Name /dev/hdg1
> VG Name sharevg
> PV Size 279.45 GB / not usable 0
> Allocatable yes
> PE Size (KByte) 4096
> Total PE 71540
> Free PE 1
> Allocated PE 71539
> PV UUID kYQB4j-fYV9-3NUa-g0Sg-H4Bk-Kx5F-wRO9G1
>
>
> hdparm -tT /dev/hde
>
> /dev/hde:
> Timing cached reads: 952 MB in 2.00 seconds = 476.00 MB/sec
> Timing buffered disk reads: 130 MB in 3.00 seconds = 43.33 MB/sec
> esplendidos:/shared# hdparm -tT /dev/hdg
>
> /dev/hdg:
> Timing cached reads: 960 MB in 2.00 seconds = 480.00 MB/sec
> Timing buffered disk reads: 154 MB in 3.01 seconds = 51.16 MB/sec
>
>
> I don't have any errors in logfiles ( syslog/messages/lvm2.log )
> Any hints what else I can check or do to improve performance? I
> mean 25kb/s on a local HD is more then just slow!
> Please please help.
>
>
> --
> Cristian Livadaru
> http://livadaru.net
>
>
>
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> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
--
Cristian Livadaru
http://livadaru.net
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