similar to: Can open requests be handled asynchronously?

Hi, I have installed Xen on Linux 2.6.11.10 <http://2.6.11.10> and i am trying to do Asynchronous Direct IO on SAS drives. The application which does the asynchronous direct io on SAS drive is running on Domain 0. Actually the IOPs what i get for a 512Bytes IO size is 67, but if i do the same operation on Linux 2.6.11.10 <http://2.6.11.10> native kernel, i get 267 IOPs.Cananyone

Sent from YoMail <bjq1016> 2016-10-01 09:30:16 wrote: Hello everyone,        First, I configured  a smb cluster of 3 nodes  with ctdb .  I found that when smb is killed or stop nomarlly , it cannot be restarted by  ctdb,  but the public ip reallo

Benchmark shows small performance improvement on fusion io device. Before: seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec After: seq-read : io=1,024MB, bw=20,343KB/s,

Benchmark shows small performance improvement on fusion io device. Before: seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec After: seq-read : io=1,024MB, bw=20,343KB/s,

Hello, When approaching hosting providers for services, the first question many of them asked us was about the amount of IOPS the disk system should support. While we stress-tested our service, we recorded between 4000 and 6000 "merged io operations per second" as seen in "iostat -x" and collectd (varies between the different components of the system, we have a few such

Hi, Seeing a drop-off in iops when more vcpu''s are added:- 3.8.2 kernel/xen-4.2.1/single domU/LVM backend/8GB RAM domU/2GB RAM dom0 dom0_max_vcpus=2 dom0_vcpus_pin domU 8 cores fio result 145k iops domU 10 cores fio result 99k iops domU 12 cores fio result 89k iops domU 14 cores fio result 81k iops ioping . -c 3 4096 bytes from . (ext4 /dev/xvda1): request=1 time=0.1 ms 4096 bytes

Holding the vblk->lock across kick causes poor scalability in SMP guests. If one CPU is doing virtqueue kick and another CPU touches the vblk->lock it will have to spin until virtqueue kick completes. This patch reduces system% CPU utilization in SMP guests that are running multithreaded I/O-bound workloads. The improvements are small but show as iops and SMP are increased. Khoa Huynh

Holding the vblk->lock across kick causes poor scalability in SMP guests. If one CPU is doing virtqueue kick and another CPU touches the vblk->lock it will have to spin until virtqueue kick completes. This patch reduces system% CPU utilization in SMP guests that are running multithreaded I/O-bound workloads. The improvements are small but show as iops and SMP are increased. Khoa Huynh

Hi What are the disk IOPS required for Asterisk call recording? I am trying to find out number of disks required in RAID array to record 500 calls. Is there any formula to calculate IOPS required by Asterisk call recording? This will help me to find IOPS for different scale. If I assume that Asterisk will write data on disk every second for each call, I will need disk array to support minimum

I have a pool with a single SLOG device rated at Y iops. If I add a second (non-mirrored) SLOG device also rated at Y iops will my zpool now theoretically be able to handle 2Y iops? Or close to that? Thanks, Ray

Excellent description, thank you. With performance.write-behind-trickling-writes ON (default): ## 4k randwrite # fio --randrepeat=1 --ioengine=libaio --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=32 --size=256MB --readwrite=randwrite test: (g=0): rw=randwrite, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=32 fio-3.1 Starting 1 process Jobs: 1

Cc the QEMU Block Layer mailing list (qemu-block@nongnu.org), who might have more insights here; and wrap long lines. On Mon, May 28, 2018 at 06:07:51PM +0800, Chunguang Li wrote: > Hi, everyone. > > Recently I am doing some tests on the VM storage+memory migration with > KVM/QEMU/libvirt. I use the following migrate command through virsh: > "virsh migrate --live

Here are some more interesting numbers, concentrating on the memory plugin and RAM disks. All are done using 8 threads and multi-conn, on a single unloaded machine with 16 cores, using a Unix domain socket. (1) The memory plugin using the sparse array, as implemented upstream in 1.9.8: read: IOPS=103k, BW=401MiB/s (420MB/s)(46.0GiB/120002msec) write: IOPS=103k, BW=401MiB/s

Hi, These patches try to support multi virtual queues(multi-vq) in one virtio-blk device, and maps each virtual queue(vq) to blk-mq's hardware queue. With this approach, both scalability and performance on virtio-blk device can get improved. For verifying the improvement, I implements virtio-blk multi-vq over qemu's dataplane feature, and both handling host notification from each vq and

Hi, These patches try to support multi virtual queues(multi-vq) in one virtio-blk device, and maps each virtual queue(vq) to blk-mq's hardware queue. With this approach, both scalability and performance on virtio-blk device can get improved. For verifying the improvement, I implements virtio-blk multi-vq over qemu's dataplane feature, and both handling host notification from each vq and

Hi Guys, I've been desperately trying to find some comparative performance information about the different mailbox formats supported by Dovecot in order to make an assessment on which format is right for our environment. This is a brand new build, with customer mailboxes to be migrated in over the course of 3-4 months. Some details on our new environment: * Approximately 1.6M+

Hello everyone, I''m wondering if the following makes sense: To configure a system for high IOPS, I want to have a zpool of 15K RPM SAS drives. For high IOPS, I believe it is best to let ZFS stripe them, instead of doing a raidz1 across them. Therefore, I would like to mirror the drives for reliability. Now, I''m wondering if I can get away with using a large capacity 7200

Gandalf, SIGKILL (killall -9 glusterfsd) did not stop I/O after few minutes. SIGTERM on the other hand causes crash, but this time it is not read-only remount, but around 10 IOPS tops and 2 IOPS on average. -ps On Fri, Sep 8, 2017 at 1:56 PM, Diego Remolina <dijuremo at gmail.com> wrote: > I currently only have a Windows 2012 R2 server VM in testing on top of > the gluster storage,

Firstly, it isn't necessary to hold lock of vblk->vq_lock when notifying hypervisor about queued I/O. Secondly, virtqueue_notify() will cause world switch and it may take long time on some hypervisors(such as, qemu-arm), so it isn't good to hold the lock and block other vCPUs. On arm64 quad core VM(qemu-kvm), the patch can increase I/O performance a lot with VIRTIO_RING_F_EVENT_IDX

Firstly, it isn't necessary to hold lock of vblk->vq_lock when notifying hypervisor about queued I/O. Secondly, virtqueue_notify() will cause world switch and it may take long time on some hypervisors(such as, qemu-arm), so it isn't good to hold the lock and block other vCPUs. On arm64 quad core VM(qemu-kvm), the patch can increase I/O performance a lot with VIRTIO_RING_F_EVENT_IDX