search for: nr_request

...ing climbed considerably (up to >12) with 'ls' taking up to 30 seconds to give any output. I've tried CentOS 4.4, 4.5, RHEL AS 4 update 5 (just in case) and openSUSE 10.2 and they all show the same symptoms. Googling around makes me think that this may be related to queue depth, nr_requests and possibly VM params (the latter from https://bugzilla.redhat.com/show_bug.cgi?id=121434#c275). These are the default settings: /sys/block/sda/device/queue_depth = 254 /sys/block/sda/queue/nr_requests = 8192 /proc/sys/vm/dirty_expire_centisecs = 3000 /proc/sys/vm/dirty_ratio = 30 3Ware menti...

Greetings all- I'm on a quest to do some serious tuning to some of my production systems. All are on CentOS 5.x ranging from 5.0 to 5.4. I've been reading up on the various IO schedulers available in the kernel and I'm hoping some of you can lend some insightful suggestions. I typically have three classes of system in production: 1. Storage/DB - Backend nodes for the application

...ed the default 64K block size and am trying various filesystems in tandem with it. I stumbled across the following recommendations on 3Ware's site: echo "64" > /sys/block/sda/queue/max_sectors_kb blockdev --setra 16384 /dev/sda echo "512" > /sys/block/sda/queue/nr_requests But am wondering if there are other things I should be looking at, including changing the IO scheduler. Any particular options I should use with filesystem creation to match up with my RAID block size? I also noted that there is a newer 3Ware driver (2.26.08.004) available than the one that com...

Hi, I'm looking for some recommendations for a "fast" fileserver regarding the hardware you use. We have different fileservers as our requirements changed over time. The "main" problem we are faced with is, that with smb (windows 7 and OS X) clients we never get really close to GBit speed on reads or writes. Using the same servers/storages with ftp, ssh, rsync, nfs we

Hello everyone, Btrfs v0.16 is available for download, please see http://btrfs.wiki.kernel.org/ for download links and project information. v0.16 has a shiny new disk format, and is not compatible with filesystems created by older Btrfs releases. But, it should be the fastest Btrfs yet, with a wide variety of scalability fixes and new features. There were quite a few contributors this time

...ed command. Command timeouts are retried by the kernel six times, so without adjusting the SCSI command timeout rsync (or anything in userspace) will be waiting three minutes after each error. Five seconds is long enough to exceed the USB bus reset cycle. Additionally, it is probably wise to set nr_requests to 1, readahead_kb to 0 and nomerges to 1 for the affected drive. Feedback on the patch is appreciated. Sincerely, Steve Thompson

Hi everyone, This is dm-ioband version 1.0.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 0.0.4 (24th April): - Performance tuning - A new bandwidth control policy is added. This policy controls

Hi everyone, This is dm-ioband version 1.0.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 0.0.4 (24th April): - Performance tuning - A new bandwidth control policy is added. This policy controls

Hi everyone, This is dm-ioband version 1.0.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 0.0.4 (24th April): - Performance tuning - A new bandwidth control policy is added. This policy controls

I was wondering if anyone''s compiled a list of places to look to reduce Disk IO Latency for Xen PV DomUs. I''ve gotten reasonably acceptable performance from my setup (Dom0 as a iSCSI initiator, providing phy volumes to DomUs), at about 45MB/sec writes, and 80MB/sec reads (this is to a IET target running in blockio mode). As always, reducing latency for small disk operations

Hi everyone, This is dm-ioband version 1.1.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 1.0.0 (posted on May 19, 2008): - Measures against high memory pressure. I/O requests to reclaim pages won't

Hi everyone, This is dm-ioband version 1.1.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 1.0.0 (posted on May 19, 2008): - Measures against high memory pressure. I/O requests to reclaim pages won't

Hi everyone, This is dm-ioband version 1.1.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc2-mm1. - Changes from 1.0.0 (posted on May 19, 2008): - Measures against high memory pressure. I/O requests to reclaim pages won't

Hi everyone, This is the dm-ioband version 1.2.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc5-mm3. - Changes from 1.1.0 (posted on June 2, 2008): - Dynamic policy switching A user can change the bandwidth control policy

Hi everyone, This is the dm-ioband version 1.2.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc5-mm3. - Changes from 1.1.0 (posted on June 2, 2008): - Dynamic policy switching A user can change the bandwidth control policy

Hi everyone, This is the dm-ioband version 1.2.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc5-mm3. - Changes from 1.1.0 (posted on June 2, 2008): - Dynamic policy switching A user can change the bandwidth control policy

Hi everyone, These patchsets are the new releases of dm-ioband and bio-cgroup which are ported to 2.6.27-rc5-mm1. dm-ioband Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same block device. A job is a group of processes with the same pid or pgrp or uid or a virtual machine such as KVM or Xen. A

Hi everyone, These patchsets are the new releases of dm-ioband and bio-cgroup which are ported to 2.6.27-rc5-mm1. dm-ioband Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same block device. A job is a group of processes with the same pid or pgrp or uid or a virtual machine such as KVM or Xen. A

Hi everyone, These patchsets are the new releases of dm-ioband and bio-cgroup which are ported to 2.6.27-rc5-mm1. dm-ioband Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same block device. A job is a group of processes with the same pid or pgrp or uid or a virtual machine such as KVM or Xen. A

Hi everyone, This is the dm-ioband version 1.3.0 release. Dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver, which gives specified bandwidth to each job running on the same physical device. - Can be applied to the kernel 2.6.26-rc5-mm3. - Changes from 1.2.0 (posted on Jul 4, 2008): - I/O smoothing take #2 This feature makes I/O requests of each group issued