Subject: [linux-lvm] lvm mirror read performance, no load
balance with PV ? - msg#00010

List: linux-lvm

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Hello mailing list,

I currently sensed that LVM2 is not load balancing reads of mirrored
LV's form their corresponding PV.

PV1 PV2
LV LV'
IO=0 IO=90MB/s

[~]# lvm version
LVM version: 2.02.39 (2008-06-27)
Library version: 1.02.27 (2008-06-25)
Driver version: 4.14.0

Distribution is Fedora 10, updated.

Is this normal behaviour, or did a make a big mistake in my configuration?

FYI:

[~]# pvs -o+lv_name,lv_size,lv_attr
PV VG Fmt Attr PSize PFree LV LSize Attr
/dev/sda2 VolGroup00 lvm2 a- 145,22G 4,97G [lvroot_mlog] 32,00M lwi-ao
/dev/sda2 VolGroup00 lvm2 a- 145,22G 4,97G [lvhome_mlog] 32,00M lwi-ao
/dev/sda2 VolGroup00 lvm2 a- 145,22G 4,97G lvdata 285,50G -wi-ao
/dev/sda2 VolGroup00 lvm2 a- 145,22G 4,97G [lvswap_mlog] 32,00M lwi-ao
/dev/sda2 VolGroup00 lvm2 a- 145,22G 4,97G 0
/dev/sda3 VolGroup00 lvm2 a- 553,28G 0 [lvswap_mimage_1] 5,03G iwi-ao
/dev/sda3 VolGroup00 lvm2 a- 553,28G 0 [lvroot_mimage_1] 15,00G iwi-ao
/dev/sda3 VolGroup00 lvm2 a- 553,28G 0 [lvhome_mimage_1] 533,25G iwi-ao
/dev/sdb1 VolGroup00 lvm2 a- 698,62G 0 [lvswap_mimage_0] 5,03G iwi-ao
/dev/sdb1 VolGroup00 lvm2 a- 698,62G 0 [lvroot_mimage_0] 15,00G iwi-ao
/dev/sdb1 VolGroup00 lvm2 a- 698,62G 0 [lvhome_mimage_0] 533,25G iwi-ao
/dev/sdb1 VolGroup00 lvm2 a- 698,62G 0 lvdata 285,50G -wi-ao

--
Mit freundlichen Grüßen, / with kind regards,
Sascha Thomas Spreitzer
http://spreitzer.name/

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Re: [linux-lvm] CLVM Snapshot HOWTO?

Paul Dugas wrote: I apologize if this has been covered already or is written up elsewhere but I can't seem to find it. I've got a couple of AoE volumes that I'm using for LVM VGs. They have GFS filesystems on LVs that are sized to fill 90% of the the VGs; 10% space left over for snapshots. I have 4 CENTOS 5.2 machines clustered and mounting the GFS filesystems. That's working well. Having used LVM snapshots in non-cluster environments before, I figured I'd just use the same logic for backing up the volumes; lvcreate -s, mount, backup, umount, lvremove. This quickly fell apart and I started to think about it more. I ended up wondering how snapshots of the volume could ever really work without coordinating with the other nodes. My question is this. Should I be able to use snapshots on clustered volumes like this? If not, are there plans to support it later? If so, can someone point me to a working example? I think you have to freeze the GFS volume before you create a snapshot, then you unfreeze it. man gfs_tool Vu _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

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Re: [linux-lvm] Signal handling in clvmd

Xinwei Hu wrote: > Hi all, > > I'm running into a problem that clvmd sometimes take a long time to > shutdown. > The clvmd itself is waiting for select to timeout in main_loop. But > since the SIGINT > (or SIGTERM) is handled in other threads, select is not interrupted as > expected. > > The attached patch tries to mask SIGINT and SIGTERM in all other threads, > to make sure the signal is properly handled in the main_loop. This > helps to reduce > the chance that we are waiting meaninglessly. > > Would you please kindly review the patch ? Thank you, That patch looks good and I've committed it into CVS. Chrissie _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Previous Message by Thread:

[linux-lvm] CLVM Snapshot HOWTO?

I apologize if this has been covered already or is written up elsewhere but I can't seem to find it. I've got a couple of AoE volumes that I'm using for LVM VGs. They have GFS filesystems on LVs that are sized to fill 90% of the the VGs; 10% space left over for snapshots. I have 4 CENTOS 5.2 machines clustered and mounting the GFS filesystems. That's working well. Having used LVM snapshots in non-cluster environments before, I figured I'd just use the same logic for backing up the volumes; lvcreate -s, mount, backup, umount, lvremove. This quickly fell apart and I started to think about it more. I ended up wondering how snapshots of the volume could ever really work without coordinating with the other nodes. My question is this. Should I be able to use snapshots on clustered volumes like this? If not, are there plans to support it later? If so, can someone point me to a working example? Thanks in advance, Paul -- Paul Dugas - paul@xxxxxxxx - 404.932.1355 signature.asc Description: This is a digitally signed message part _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Next Message by Thread:

Re: [linux-lvm] lvm mirror read performance, no load balance with PV ?

Sascha Thomas Spreitzer [sascha@xxxxxxxxxxxxxx] wrote: > Hello mailing list, > > I currently sensed that LVM2 is not load balancing reads of mirrored > LV's form their corresponding PV. Yes, it just reads from the default_mirror (i.e. primary mirror leg). There is a read-balancing patch. It is not upstream yet and most likely not there in your kernel either. Thanks, Malahal. _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Subject: [linux-lvm] lvm mirror read performance, no loadbalance with PV ? - msg#00010