similar to: IO Schedulers

Hi, all, I just found out that xen assigns the NOOP disk scheduler for linux guest OSes. Dom0 uses cfq scheduler (it is the linux default). Is there a reason for xen to turn off disk request merging in the quest OS by selecting a NOOP scheduler? Is it because the request optimization will be performed in dom0 or VMM ? Thansk in advance, Jia. _______________________________________________

Hi all, can someone comment on the state of the hifn(4) driver? I've recently upgraded my 6.2-STABLE workstation to RELENG_7, and I'm now experiencing system lockups that seem to be caused by the hifn(4) driver. I've got a Soekris vpn1401 card to help with GELI disk en- cryption. Reading from a GELI volume is causing the system to freeze completely, which does not happen if

Hi, I'm building a test asterisk server and building the latest kernel I got to wonder if there are any specific recommendations about schedulers and so forth for optimum performance. There are a few areas that raise questions in my mind and I wonder if anyone has any opinions/comments on which settings are most suitable for use with asterisk: SLAB Allocator (SLAB or SLUB?) Tickless

This patchset expands traditional CFQ scheduler in order to support cgroups, and improves old version. Improvements are as following. * Modularizing our new CFQ scheduler. The expanded CFQ scheduler is registered/unregistered as new I/O elevator scheduler called "cfq-cgroups". By this, the traditional CFQ scheduler, which does not handle cgroups, and our new CFQ

This patchset expands traditional CFQ scheduler in order to support cgroups, and improves old version. Improvements are as following. * Modularizing our new CFQ scheduler. The expanded CFQ scheduler is registered/unregistered as new I/O elevator scheduler called "cfq-cgroups". By this, the traditional CFQ scheduler, which does not handle cgroups, and our new CFQ

Hello, I found a strange problem with allocationg big files on drive. For example in guestfish I allocate large disk image for example: $ guestfish ><fs> allocate test.img 20G When an image allocating, there is a big slowdown of guest OSes, launched on host machine, and on different drives. For Linux guests with virtio drivers, there is no so big performance penalty, but for FreeBSD

Hello, I found a strange problem with allocationg big files on drive. For example in guestfish I allocate large disk image for example: $ guestfish ><fs> allocate test.img 20G When an image allocating, there is a big slowdown of guest OSes, launched on host machine, and on different drives. For Linux guests with virtio drivers, there is no so big performance penalty, but for FreeBSD

I have been chasing down the way the inode and page caches are structured and handled, but there is a mystery I have not been able to track down yet. How does the I/O queue that dirty inodes and pages are put into when it's time to flush them out to disk get picked up? Also, where are the sources for the I/O schedulers? I haven't been able to locate them yet either. I know this

I understand Oracle currently recommends using the deadline scheduler because of a bug in cfq. In reading a recent thread on nahant- list at redhat.com, using the deadline scheduler on an NFS server reduced IO wait significantly. Also, the description of the deadline scheduler sounds like it would be ideal for databases. Does Oracle have any recommendation wrt. sticking with the deadline

Hi, short question: Which schedulers are recommended on running a samba smb server using > 1000 files but high I/O on reads/writes on those files? - Julian Wichtiger Hinweis: Der Inhalt dieser E-Mail ist vertraulich und ausschlie?lich f?r den bezeichneten Adressaten bestimmt. Wenn Sie nicht der vorgesehene Adressat dieser E-Mail oder dessen Vertreter sein sollten, so beachten Sie bitte,

Hi, If you are not already tired of so many io controller implementations, here is another one. This is a very eary very crude implementation to get early feedback to see if this approach makes any sense or not. This controller is a proportional weight IO controller primarily based on/inspired by dm-ioband. One of the things I personally found little odd about dm-ioband was need of a dm-ioband

Hi, If you are not already tired of so many io controller implementations, here is another one. This is a very eary very crude implementation to get early feedback to see if this approach makes any sense or not. This controller is a proportional weight IO controller primarily based on/inspired by dm-ioband. One of the things I personally found little odd about dm-ioband was need of a dm-ioband

The Wikipedia pages about schedulers are quite informative. I don't know _why_ this makes a difference, but it does seem to make a small one. Even though for a single process (guestfsd) it would seem that the choice of scheduler should make no difference. BTW the default scheduler in the guest is 'cfq'. http://en.wikipedia.org/wiki/Noop_scheduler http://en.wikipedia.org/wiki/CFQ

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

Hello, I have summarized the topics for the IO controller mini-summit and written the ideas seen in the mailing list. - The place where IO controller should be implemented - Block layer in conjunction with the IO scheduler - Common layer right above the IO scheduler - CFQ enhancement. - Both block and common layer, users can select whichever controller they want. - VFS layer -

Hello, I have summarized the topics for the IO controller mini-summit and written the ideas seen in the mailing list. - The place where IO controller should be implemented - Block layer in conjunction with the IO scheduler - Common layer right above the IO scheduler - CFQ enhancement. - Both block and common layer, users can select whichever controller they want. - VFS layer -

Hello, I have summarized the topics for the IO controller mini-summit and written the ideas seen in the mailing list. - The place where IO controller should be implemented - Block layer in conjunction with the IO scheduler - Common layer right above the IO scheduler - CFQ enhancement. - Both block and common layer, users can select whichever controller they want. - VFS layer -

Is there a way to nice the IO on a process such as dd? If not, what could be a way to control the IO level of such a process from bogging down a server to severely. Thanks, jlc

This was an email I sent to xen-devel a while ago without getting a response. I''m reposting it here in case someone knows more. Hello all, I''m able to consistently reproduce lockups in my domU with heavy I/O with the following error: 36841.420662] INFO: task rsyslogd:15014 blocked for more than 120 seconds. [36841.420843] "echo 0>

As long as I'm still awake, I tried to install CentOS 5 (earlier) from a DVD I downloaded via bittorrent about a week or so ago. It boots fine, but once it starts to load the kernel (in graphics mode), it gets to the point where it announces the four i/o schedulers and then stops dead. No disk activity, no DVD activity, nada. Is there a known problem here and if so what, or is this a new