High write latency

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• Satellite A500-1DN - high DPC latency resolved

  Hi all!

  All first of all sorry for the bad English!
  I am writing because this problem drove me crazy in the half of the year. I got cracking audio etc. thanks for the high dpc latency time but finally I managed to understand how to clear my A500 these boring of CPD points. I made these:

  1. update of the BIOS (1.90)
  2 use this VGA nVidia Driver: 257.21. Only this one works. I tried every existing. If you have another type of satellite, but a Geforce 230 M GT in there and you have high latency tell him!
  3. use wlan driver atheros version 8002580
  4. use optimzer wlan. Name: wopt021 (disable background scanning and enable streaming mode)
  If you use WiFi, jumping 3. 4.

  Now my A500 works correctly, I am really satisfied with it :)
  I hope that this guide will help all those who have the same problem!

  Good bye

  Hi atibrd,

  I'm happy to hear that you have found a solution to this "problem" but I must say also I never had problems with my Satellite A500 and I put t know what you mean with a DPC latency. I use my Satellite A500 with OS preinstalled Toshiba and the latest version of the BIOS. Everything works fine, even some newer games run great on it.

  In addition, with regard to the nVidia display driver I want to give you a little advice: be careful with 3 third party drivers, even from nVidia. No one from nVidia has tested this driver in particular on the Satellite A500. If the installation goes on your own risk because it doesn t have a protection against overheating.
  That's why I only use the drivers provided on the official website of Toshiba directly. They are tested and working 100% correctly.

  In any case, maybe for some people they have this DPC problem too it s useful. :)

• SNMP values for Volume read/write latency

  I use SNMPWALK to collect the OID for my EqualLogics (I have followed for several clients). I have a lot of success overall, but my biggest problem right now is to determine what SNMP values are available for things like latency playback and Volume write latency. I have settings for latencies of Member below.

  Reading Member latency

  . 1.3.6.1.4.1.12740.2.1.12.1.4.1.

  Latency of writing Member

  . 1.3.6.1.4.1.12740.2.1.12.1.5.1.

  I even have the name of the Volume (below), which suggests, I'm close, but I need to be absolutely sure (since I will charge the exact relationship).

  . 1.3.6.1.4.1.12740.5.1.7.1.1.4.

  Can someone help me? Is there a guide somewhere with any of this information?

  The MIB are considered as "document open" but be careful, some values are the beginning of the table and are cumulative.

  My suggestion is to install SANHQ that will provide this level of information and a whole lot more.

  SANHQ is available on the site Web of Equallogic.

  Kind regards

• Oh, the irony? High DPC latency with idle CPU - gives more stable, more low-latency DPC CPU usage 100%

  Just like in the title,

  I tried everything, disabling components, elimination of most of my RAM, update BIOS and loading failsafe and optimized defaults, etc. - and one thing I noticed is that Prime95 running x 64 on all hearts eliminates the peaks high in 1.2.0 DPC latency checker. Audio stuttering, what original research for corrections me, brought me to DPC latency checker.

  It's really strange that the 100% CPU usage would cause the DPC latency stabilize (mine hovers around 350-450 microseconds in the full use of the CPU, but in use slowed parameters or moderate apparently something causes a DPC peak at ~ 4100us max).

  Let me know if you figured it out!

  Model name : GA-EP45-UD3P(rev. 1.6)
  --------------------------
  M/B Rev : 1.6
  BIOS Ver : FE
  Purchase garage : Newegg.com
  -------------------------------------------------------------------------------
  Brand VGA : ATI model : 5770
  Brand CPU : Intel model : Quad 9400 speed : 2.66
  Operating system : Win 7 64 bit SP :
  Brand memory : G.SKILL Type : DDRII
  Memory size : 4 GB, speed : 800
  Power supply : Antec Neopower 550 W

  Hi Frankie,

  We understand that you too met the same scenario as this 6 year old thread. Some resolutions are always topical, while others are no longer applicable due to constant updates and corrections in the course of the last years.

  However, to resolve your concern, you can view article utilization of the processor for Windows 7 .

  Let us know how it goes.

• Periods of high disk latency

  Hello - I just moved to a new company and I am working on virtualization of most of the servers here. It's a small IT shop with 20-30 servers. I bought 3 new HP DL380 G7 servers and I have about half of the 20 converted physical servers. I noticed a problem that appears and it seems random times.

  There are 2 tables (13 6 disks raid, raid 5 disks 5) 2 luns, a VMFS shared LUN between the 3 servers. This is on a HP P2000 G3 FC SAN (already in place before). Every once and a while I notice latency of very high disk it seems that only on the LUNS on the Raid 5 array.

  I've attached a screenshot of ESXTOP running on all servers ESX 3 showing the high latency. I can understand if there was a very high use but is not really yet everything going on at this time, as you can see on the screenshots. The tweak only I made so far is to increase the depth of queue to 64.

  Brocade 8 GB HBA using hanging on the HP (Brocade) switches. Everything works to 8 GB and all readers of the San are 6 GB SAS.

  I'm new on this and HP options without, came from one world IBM DS4xxx, so I do not know that how still to watch the performance on the SAN itself, the web interface does not have all followed what-so-ever.

  Any help is appreciated-

  Thank you

  Well, I agree that it was a question of ownerhip lun.

  The extent of maxing controllers, theres more to the issue than just flow.  Its actually very common on these lowend tables except if you make something trivial like a streaming the CPU controller will not be able to do in the face of a workload of IOPS / s high (or even moderate).  This isn't the bandwidth, it is the CPU on the controller.  His community does even more than you might expect on the bays of large companies (HDS USP, EMC Symm, etc.).

  -Matt

  VCP, VCDX #52, Unix Geek, Nerd of storage

• read/write latency average lun 24 hours a day

  How can I get medium and playback latency of writing for each LUN via PS?  I know how to get the latest version, but does not know how to get a 24 hours on average.  If it's important storage we use iSCSI is shared between three servers essentials ESXi with vCenter running in a virtual machine.

  Thank you...

  Can of course.

  First let's look at the available historical intervals

  Get-StatInterval | select Samplingperiodsecs, name,  storagetimesecs
  

  This will show

    SamplingPeriodSecs Name                                                                                StorageTimeSecs
    ------------------ ----                                                                                ---------------
                   300 Past Day                                                                                86400
                  1800 Past Week                                                                                604800
                  7200 Past Month                                                                                2592000
                 86400 Past Year                                                                                31536000
  

  To only watch the first 2 columns, do you see the historical intervals 1-4

  In minutes/days, what gives

  Historical Interval 1    5 minutes
  Historical Interval 2    30 minutes
  Historical Interval 3    120 minutes
  Historical Interval 4    1 day
  

  In addition to the name in the second column, the third column shows how much time you will have access to statistical data of this interval.

  For example, interval of 1 history with the 5 minute interval is kept for 1 night.

  If we get statistics of 1 day ago, we will liquidate history interval 2, with the interval of 30 minutes.

  Let's get some stats

  $esxName = 
  # Sample instance
  $tgtInstance = "naa.600507680180809ed000000000000179"
  
  $stats = Get-Stat -Entity (Get-VMHost $esxName) `
            -Stat "disk.deviceReadLatency.average" `
            -Start (Get-Date).AddDays(-2) `
            -Finish (Get-Date).AddDays(-1) | `
            where{$_.instance -eq $tgtInstance}
  

  As see you in the settings - Start and - finishing we call statistics data between 48 and 24 hours.

  All sampling intervals will be 30 minutes (interval 2 historical).

  To get the average day you can do

  $dayAvg = ($stats | Measure-Object -Average -Property Value).Average
  

  Now suppose we recover more than 1 day of data and we want that day averages, you could do that

  $esxName = 
  # Sample instance
  $tgtInstance = "naa.600507680180809ed000000000000179"
  
  $stats = Get-Stat -Entity (Get-VMHost $esxName) `
            -Stat "disk.deviceReadLatency.average" `
            -Start (Get-Date).AddDays(-5) `
            -Finish (Get-Date).AddDays(-1) | `
            where{$_.instance -eq $tgtInstance}
  $dayStats = $stats | Group-Object -Property {$_.Timestamp.Day}
  $dayStats | %{
       $dayAvg = ($_.Group | Measure-Object -Average -Property Value).Average
       Write-Host "Day" $_.Name $dayAvg
  }
  

  What about what you are looking for?

• 6735 s his stuttering, high DPC latency

  6735 s aged 8 months.

  A month ago I started to notice the audio stuttering in video to download websites such as youtube. The problem tends to appear after about an hour of computer use / navigation. Recently, however it has started to affect the mpg and mp3 files played locally on my hard drive. The problem is much worse that a download is in progress (i.e. any download, the media files not only). I ran a DPC latency checker that I found on the web and I found that when I'm browsing or downloading files DPC latency goes through the roof.

  About a week before I first noticed this problem I have updated graphics drivers from ATI (Catalyst v9.8, then recently v9.10), so I think it has something to do with it.

  I tried to disable the WIFI / network cards, bluetooth, USB, CDROM drive, ATI drivers uninstall audio drivers, firewall, antivirus, killing all the processes that are unnecessary in the Manager of tasks etc. Only a reboot will solve the problem (for an hour or two before returning)

  Does anyone else have this problem? It drives me nuts having to restart my computer for all hours.

  Update: turns out the culprit being the ZoneAlarm firewall. I had heard of people having problems with the COMODO firewall, so I tried to uninstall ZoneAlarm and all is well again. Note must be a uninstall complete, just disable or turn off ZoneAlarm was not enough.

  See you soon.

• Copy of simple file IO latency?

  A single copy of the file on the disk C: local, from one folder to another on a latency of disk causes of VM (LVAD/wr) to go up to 300 m, if I give the virtual machine to Windows 2008 R2 another drive, D:, that is located on another logical unit number, a copy of the file to C:\ D:\ makes same latency LVAD/wr go up to 1500ms. The high write latency is measurable on the other virtual machines on the same LUN.

  The same file copy activity on a virtual machine to Windows 7 on the same left LUN disk latency (LVAD/wr) less than 20 ms.

  Latency is measured with esxtop on the host and iometer within guests. There is no other virtual machine running in my tests.

  Is the latency of disk * supposed * to go so high a simple file copy? It would make me uncomfortable if someone copies a file to another folder on the file server could explode latency of writing for all other virtual machines too. Or is he not supposed to, and I've misconfigured something?

  Our facility:

  Server is HP Proliant DL165 G7

  SAN is HP MSA P2000i G3

  ESXi 5.0 driver cumulative 2

  The server has 4 cards gigabit ethernet. vmnic0 is connected to a switch, here the networks management and virtual machine are connected. vmnic1 is not used. vmnic2 goes to the port A0 on the SAN. vmnic3 goes to the port A1 on the SAN. Controller B on the MSA was arrested. The SAN has two LUNs. Using 'Manage paths' I disabled path vmnic2-A1 to Lun0 and vmnic3-A0 to Lun1, so each LUN has a dedicated cat6 cable. Both the Windows 2008R2 and Windows 7 virtual machines have been installed at Lun0.

  Thanks and strange that this behavior did not get all the attention. It's a bit it could cause strange results on the shared storage if several virtual machines are competing for the same disk systems.

  It could be that in reality is this kind of wholesale IOs often not possible, should it really be 32 MB of available continuous free disk space.

• Latency of DISK vscsiStats troubleshooting

  Hello forums.

  Could use an expert overview for a problem I have with some VM.  Use of resources is not the ability in some way.  No pretense of CPU but VM are slow - and often its bad or sometimes just slow.  The virtual machine had this, but for some time now, I know that we add more virtual machines in our lab, so that could explain the latency

  I would like someone offer help on using vscsiStats to vmdisk of troubleshooting related problems.  On the virtual machine, as I watched in perfmon, I noticed a somewhat long average disk queue length.  I ran vscsiStats and obtained after 30 minutes.  Please let me know if I understand this right.

  vscsiStats run with string only included latency IOs not in read/write latency.  Both drives are on the same data store.

  VMDISK 1

  Histogram: latency of IOs in microseconds (US) virtual

  machine worldGroupID

  121 min

  Max 14440236

  average 327165

  County 15524

  Histogram of the frequency

  Limit of bucket

  0                            1

  0                            10

  0                            100

  1488 500

  1929 1000

  1453 5000

  1618 15000

  1688 30000

  1070 50000

  1546 100000

  4732 100000

  VMDISK - 2

  Histogram: latency of IOs in microseconds (US) virtual

  machine worldGroupID

  159 min

  Max 14245418

  average 478629

  County 3446

  Histogram of the frequency

  Limit of bucket

  0                                 1

  0                             10

  0                             100

  1722 500

  146 1000

  136 5000

  15000 65

  30000 59

  50000 46

  100000 88

  1184 100000

  I don't really understand our provision of storage very well and I apologize I'm trying to learn it.  We use NetAPP, but I don't think that we all use the NetAPP storage.  These discs are fixed with 4 Gbps HBAS that are a SATA drive.

  My understanding of the above is the following:

  4732 written = & gt; 1 tenth of a second

  1546 written & lt; =.1 tenth of a second

  1070 written & lt; =.05 hundredths of a second

  My math may be a little off but it's a lot of latency for disk i/o? Your help is appreciated.

  See you soon,.

  Chad King

  VCP-410. Server +.

  Twitter: http://twitter.com/cwjking

  If you find this or any other answer useful please consider awarding points marking the answer correct or useful

  You're right, it comes by I/O latency. This means that an important part of your IOs have a greater than 100 milliseconds latency, it is high enough to be honest and I'm not surprised if you would notice general slowness. I wonder if you have for example checked if your disks are aligned or not? This could contribute to this level of latency. I also wonder how many links, you must return to your file server?

  Another thing worth investigating is the use of the processors of the spin.

  Duncan

  VMware communities user moderator | VCDX

  -

• In mode Optimus (W520) high battery drain

  TL; DR version:

  When the BIOS is set to the integrated graphics card, the energy consumption on W520 is 10-14 watts. If you select mode Optimus, it's more than 25 watts (less than 4 hours). What gives?

  ---------------------------

  Hi, I got W520 (2820qm, Quadro 2000 m, 16 GB HyperX) and as I was installing a new SSD drive, I reinstalled Windows 7 from zero (mode UEFI), installed the driver ethernet card and all of the installed update system you need.

  The problem is that when the system is running on battery power, the power consumption is more than 25 watts, resulting in less than 4 hours of autonomy, unlike the reports + hours mode Optimus 7 comments. I suspect it is a problem with the drivers/settings/etc. to card technology/nVidia Optimus, since when I switch to the integrated in the BIOS graphics, use of power supply goes from 10 to 14 watts, which seems normal.

  I have already tried:
  -installed system update drivers Lenovo
  -latest Intel drivers and more recent nVidia Verde drivers
  -Latest BIOS
  -activity nVidia icon in the status bar, he said that no programs are running on discrete GPU
  -settings nVidia resetting to default values
  -searching the Internet for several hours (found nothing) solutions
  -juggle with the Manager of power, trying to Stretch Battery settings (got as low as 20 + watts, who is still only 4.5 hours)

  Anyone have any idea what may be wrong or anything to check? Is this a known issue?

  (Also, on an unrelated note: has high DPC latency with audio abandon, had to disable TCP and discharges of IPv4 on Intel wired NIC)

  It works fine for me with a clean install, latest version of the bios, latest intel + nvidia drivers. Manager power shows the nvidia icon or not? The gauge must be 100% for graphics, no icon showing nvidia. The nvidia tray icon should be gray.

• Intrigued by the DPC latencies

  Hello

  I noticed that in my Vista 32 bit, I have strangely high DPC latencies
  (something is often read in DPC latency Checker 1000us)
  My system seems however works smoothly (games and everything). I disabled
  all unecesarry drivers, but
  'problem' remains (even in an emergency mode).

  Xperf indicates the maximum duration of use of the processor of the CPD
  Ntkrnlpa.exe - 69us
  NDIS - 67us
  Usbport.sys - 40us
  nvmimx32.sys - 40us
  nvlddmkm.sys - 30us
  Storport.sys - 30us
  Tcpip.sys - 26us
  nvstor.sys - 19us
  NetBT - 15us
  hdAudBus.sys - 14us
  NETIO.sys - 13
  and so on.

  If I have summarized all these latencies max is not 1000us on DCP latency
  Checker.
  Games, music video is fine without glitches, but strange is Windows Photo
  Viewer, I my class presentation dxgkrnlg.sys is 1.3ms max. There is problem
  what I have run the presentation for awhile (presentation does not
  en_douceur, but the picture of the changes are stuttering) something freaks out and fires
  TDR ending with bsod because driver Nvidia can not recover. I do not know
  If it's related or not...

  Another thing is that my Vista 32 bit is high latency and low latency Vista 64
  continuing execution on 40us (as seen in the DPC tester).

  Any suspicion or so?

  OK, so after a while I have the real answer.

  My DPC latency difference was caused by the settings (various in operating systems) energy saving

  Windows is the best and the rules.

• Windows Vista, the network latency got bad

  Yesterday, I changed the network router on my Windows Vista (edition Home premium) and this led me to run some of the internet speed test sites.  I see high network latency on the network speed available test sites.  The download speed is very good, but my network on my Windows Vista system latency time increased from 19 ms to about 500 ms.  It is quite a big change (X 25), so I'm a little worried about it.  I don't think that it is a router problem because I also have a Windows XP system that is connected to the router, and he still sees about 19 ms network latency.  Just to be sure, I changed the system of Windows Vista and Windows XP system router ports, and the latency of each system has not changed, so I don't think that it is a router problem.

  I think so the network on Window Vista system stack has been damaged in some way, and I'm looking for help to repair.  My first thought was the restoration of the system, but I can't go far enough to make it useful.  The only system restore point that I currently have (for some reason any) yesterday, and it shows the same 500 ms of latency of the network on the Windows Vista system.
  Can someone help me to troubleshoot or fix this problem?
  Thank you very much.
  -Roger

  Well, one of those moments of "Doh!" ... found another article on the internet, this time, it gives an idea for my system... I was using Chrome 3.0 as my browser when I ran network speed sites that gave me the time of high latency, with that I was worried.  I found that my time of network latency on Vista, as measured by Firefox 3.5.3 is about 19 million, and for IE8 is about 10 MS, which both are very good.  My conclusion therefore is that Chrome 3.0 marked the beginning of a new era of the network latency that is bad for me.  Or maybe it's Eset Nod32, antivirus, it does not matter (when I turned Nod32 which made no difference to the number of Chrome, well off)...

  I had no idea that Chrome 3.0 was this badly inconsistent with everything that he fights with on my computer Vista, but I don't need because I have a couple of other browsers which are very good.

  Interesting, even when...

  -Roger

• Create IO and latency by group reports

  We have recently upgraded from standard to Enterprise, and I have reported using Business Views. All these points of view contained warehouses of data for a San, or type of disk on the san. I was including a chart with an i/o write latency, latency playback and time of total latency for all data stores as a whole in the last week, etc. See photo.

  

  How can I configure something similar within the company?

  Hi Roger,

  You can do this with an array of dashboard.

  Foglight, 'Services' are a group of assets, similar to the views of the company. You can create a Service of your particular data warehouses. Or drag and drop on all your data warehouses.

  Then go and create a dashboard. Select the Table. 2 columns by default. When you select settings, explore current/Max.

  

• At what level is the store of data latency measured?

  Hello

  I have a question about latency of data store. I see that, generally, 20 to 30 ms latency limit before having the performance issue, but at what level is this limit? It is the seat of the latency of the VM? See vsphere?...

  In Vcops, when I select a data store and access operation - details see read/write latency: see comments AVG or device AVG? (see image below)

  

  When I select a VM in Vcops to see the latency time "of virtual machine", what is the difference between latency vDisk and the VM latency data store?

  

  I know there are a lot of questions in one thread, thank you in advance to those who take the time to answer.

  As esxtop counters, you have different counters to measure different parts of the stack. If you have latency at a disk level your queues will be filled and reflected. Latency of disk order is good enough to pick up underlying storage latency, but it depends what resource you are watching. The attributes derived from 'latency' exist here and there which are calculated based on the type of storage/etc to simplify your life and give you one place to search.

  When you start to look at the latency of the queue, you must keep in mind that focuses only on the queue. Take a look at the Duncan article (ESXTOP - bricks yellow) on it and your questions will probably be kept clear with regard to what are the bits/s and for the disk counters.

• Alarm for the latency of disk esxi-home

  I would like to set a new alarm to monitor all esx host disk latency in our vCenter.

  We found the settings, to set up this point for a virtual machine.

  [vCenter alarm-> add new detector for a virtual machine-> trigger Type: disc Total VM Max (ms) latency]

  So we need the same alarm, but for the esx host. But I can't find the right trigger type neighter events on the right (for which we can configure an alarm).

  The problem is that sometimes the Raid Controller battery is defective and then we notice everything by checking the performance of the disks-esx table:

  

  We need an alarm for exactly this measure: drive higher (ms) latency.

  I also searched for setting up an alarm in the store of data according to, but without success.

  Maybe someone has an idea how to set up such an alarm.

  Hello!

  There isn't any support in Client vSphere or vCenter. You can use esxtop to know but there is a lot of work to get a sort of wake-up call.

  A VMware product for this is vCenter operations, but it might be too depending on your environment.

  There is many products from 3rd party who will do that for you. vKernel VoP (formerly called vFoglight and I think that Veeam One will do this for you.)

  -Martin