Re: [Xen-devel] blkback disk I/O limit patch

[Vasiliy Tolstov <v.tolstov@xxxxxxxxx>]

Sorry forget to send patch
https://bitbucket.org/go2clouds/patches/raw/master/xen_blkback_limit/3.6.9-1.patch
Patch for kernel 3.6.9, but if that needed i can rebase it to current
git Linus tree.

2013/1/31 Vasiliy Tolstov <v.tolstov@xxxxxxxxx>:
> Hello. For own needs i'm write simple blkback disk i/o limit patch,
> that can limit disk i/o based on iops. I need xen based iops shaper
> because of own storage architecture.
> Our storages node provide disks via scst over infiniband network.
> On xen nodes we via srp attach this disks. Each xen connects to 2
> storages in same time and multipath provide failover.
>
> Each disk contains LVM (not CLVM), for each virtual machine we create
> PV disk. And via device mapper raid1 we create disk, used for domU. In
> this case if one node failed VM works fine with one disk in raid1.
>
> All works greate, but in this setup we can't use cgroups and dm-ioband.
> Some times ago CFQ disk scheduler top working with BIO devices and
> provide control only on buttom layer. (In our case we can use CFQ only
> on srp disk, and shape i/o only for all clients on xen node).
> dm-ioband work's unstable when the some domU have massive i/o (our
> tests says that if domU have ext4 and have 20000 iops sometimes dom0
> crashed, or disk coccupted. And with dm-ioband if one storage node
> down sometimes we miss some data from disk. And dm-ioband can't
> provide on the fly control of iops.
>
> This patch tryes to solve own problems. May someone from xen team look
> at it and says how code looks? What i need to change/rewrite? May be
> sometime this can be used in main linux xen tree... (i hope).
> This patch is only for phy devices. For blktap devices i speak with
> Thanos Makatos (author of blktap3) and may be in future this
> functionality may be added to blktap3..
>
> Thank You.
>
> --
> Vasiliy Tolstov,
> Clodo.ru
> e-mail: v.tolstov@xxxxxxxxx
> jabber: vase@xxxxxxxxx



-- 
Vasiliy Tolstov,
Clodo.ru
e-mail: v.tolstov@xxxxxxxxx
jabber: vase@xxxxxxxxx

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