Latency of disk queue

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• 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

  -

• The disk queue length

  I have a dell inspiron 3520, windows 8. I had windows update problems, and I can't update to windows 8.1. I can not reset or refresh windows 8. I was checking different things on my laptop and I went into advanced system tools and generated a system health report, and I got this warning: the average disk queue length is 3. The disc may be its maximum transfer due to the flow capacity and disk seeks. What does that mean? I would be very happy any help I can get with that.

  Thank you

  Cheryl Christopherson

  Suggestion in this thread: http://answers.microsoft.com/en-us/windows/forum/windows_7-performance/disk-queue-length-problem/4ee9b15a-0c02-435b-92ab-9d9a41ae84a5

  See also:

  Ref: https://technet.microsoft.com/en-us/library/cc938625.aspx

  AVG. disk queue length. logical disk or physical disk, to determine the number of i/o requests in the queue for the service. Note that this may overestimate the actual length of the queue, because the meter includes requests queued waiting and continuous training. If the average disk queue length is greater than two times the number of batteries, then you are probably developing a bottleneck. With a set of volumes, a queue that is never more short the number of active physical disks that you develop a bottleneck.

  Figure 8.8 shows a bottleneck of disk with high disk usage and a long queue.

  

• Server 2003, Server SQL 2000 gel. maximum disk queue

  Yeh yeh her legacy I know but its still in production.

  Here are the specs;

  • farm of about 30 guests
  • vsphere vcenter 5 servers
  • San iscsi EMC to 24 pins
  • Server is server 2003 32-bit. the memory is about 3.4 GB used of CPU resources available 4 GB is 2 Sockets with 4 cores per socket. P2V has had a number of years
  • all other servers seem to be good and have performance issues.

  I have a question where the 2003 server is suspended and become unresponsive. End users who use the software and the website that communicates with the SQL database also complain of poor performance. the UI Office stops, then crashes at the same time

  I checked the performance of the server vsphere host running this comments and resources are not overloaded. Maximum rate of CPU is around 40%

  I loaded the performance monitor on the comments and added leading % and page of memory/cpu, av/disk queue counters. When the user interface is blocked, users experience performance issues line av/drive hits 100%. Queue drive returns to normal and the responsiveness performance returns.

  I also ran perfmon on another server that resides in the same data store server and vsphere and I don't see any of the questions / crashes or maximums of the disk queue, so it seems to me be associated comments.

  Does anyone have any suggestions?

  Yes you can do for the person who is affected, yes as by EMC to proceed with the restart,

  I always suggest don't do nothing too your storage space for production servers, perform a good capacity analysis and ensure that the load across storage are well balanced.

  All the best and hope you will fix the problem...

• high avg disk queue length

  Hello..

  I just installed a VMware ESXI 4.0 on my IBM M2 Server (7947-ZGA).

  on this machine, I have 2 comments to a single server running SBS 2008 and the other Server 2008 STD x 64 with SQL 2008 installed

  I have a problem with my SQL 2008 X 64 STD performance. He works a small base SQL (4 GB) for a saving program.

  When I run a test of READING/WRITING in the saving program is slow compared to the server that was running in the database before

  If look at the performance monitor on the high SQL im expering avg disk queue length.

  the server is installed with 16 GB of ram, 8Gbg is committed to each guest.

  the server is installed with 2 the 4 physical CPU cores are committed to each guest

  the server is installed with 8 disks SAS

  system disk 2 disk (RAID1) (two comments are installed on the)

  sharing data on disk (RAID5) 3, Exchange database on the SBS server and SQL for SQL server database.

  share data on disk (RAID5) 3, NEWSPAPER Exchange on the SBS server and log SQL for SQL server.

  There is that 30-35 users on the net, so Exchange DB and DB SQL on the same disks should not be a problem, I think.

  enyone who has an idea to set the avg disk queue length?

  Is this the same physical disk configuration that you used for the physical versions of these installs?

  If you find this information useful, please give points to "correct" or "useful".

• Latency of disk metrics

  Latency of disk metrics

  Can only be recovered through the SDK?

  Thank you

  Jan

  Yes, take a glance performanceManager and specifically disk i/o counters where you will be able to retrieve the parameters of disk latency

  =========================================================================

  William Lam

  VMware vExpert 2009

  Scripts for VMware ESX/ESXi and resources at: http://engineering.ucsb.edu/~duonglt/vmware/

  Twitter: @lamw

  repository scripts vGhetto

  Introduction to the vMA (tips/tricks)

  Getting started with vSphere SDK for Perl

  VMware Code Central - Scripts/code samples for developers and administrators

  150 VMware developer

  If you find this information useful, please give points to "correct" or "useful".

• 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

• Latency of disk windsurf ESXi 4.1

  I have a new installation of ESXi 4.1 on a HP Proliant DL180 G6.  I gave a few VM, but I see a latency absurd in the disks, read latency is about 30 ms, and writing remains about 60 ms with spikes in the 400-500 + range whenever one of these virtual machines do anything associated with write or read something other than the smaller amount of data.

  The storage is local and it is the 7200 RPM SATA drives, and to make it worse, they are, in a RAID 5, I expected to see a latency, but I believe that what I feel is average higher than it should be.  Is what I feel to be expected considering the disks I use or is there something I need to look?

  Welcome to the communities.

  Your disk controller has the supported battery write cache module installed? Without it and write caching enabled performance will be poor. How many drives in your RAID 5?

• "the high latency of disk" on the performance tab appears

  Is it normal to have absolutely no activity on the upper Desk of the default latency '1 day summary' tab in vCenter performance? I have the latest updates on vCenter and ESXi 4.0.0 running on my hosts. Guests show CPU, disk use, and use of memory... but zip on this disk latency. We use a copula of IBM Nseries 6040 boxes I think (same as Netapp 3040) with NFS (no fibre channel).

  Since NFS is the network file system and not a block, file system you get not disk performance statistics, it is normal.

• Windows Oracle disk queue 100%

  Hello

  I use a database of Oracle 9i on Windows Server 2003 Standard.

  When I run a query that runs through about 30 large tables the disk i/o goes up to 100% for a few minutes.

  Are there performance advice you can give me to study?

  I'm guessing that something is configured wrong on the Oracle side, but I don't know where to look.

  Its a Raid 5 disk configuration.

  Thank you.

  Joining tables that much is not exceptional. I'm working on view now po_negotiated_sources_v EBS who joined about 20 tables. There are many points of view with more.

  In General, I discover I/O no excessive disc not as a problem but as a symptom of a problem. The solution is not not to adjust the e/s, but to remove the need for input/output. If you follow the usual SQL tuning cycle, starting with the collection of information on the execution plan, tables, indexes and statistics of the object and system.

  --

  John Watson

  Oracle Certified Master s/n

• ESXi 5.1 SMV degrade slowly with until this only unusable disk latency issues. How do I troubleshoot and resolve?

  Dell R710 servers

  Reference Dell Perc 6 / i raid controllers

  3 500 GB hard disks in a raid 5 configuration

  2 data stores.

  3 Red Hat linux 5.5 VMS servers.  Database intensive applications with e/s running high.

  Symptom: Servers become very slow or does not respond over time. Each VM restarts does not help. A restart of the entire server ESXi provides immediate relief and the process begins again. I can only run the servers about a week before I have to restart again.

  Disk latency may average in the range of 100 to 300 before a restart. After the reboot, the latency average in the range of 5 to 9 and slowly grows as the days pass.

  Use memory and CPU look normal to me. Uniformly flat even when the servers seem to have trouble.

  Any ideas what would cause this or how to fix?

  Please go to esxtop on the server and press D to see the latency of disk.

  FollowESXTOP - yellow bricks

  to troubleshoot latency.

• Data store / latency issues with HP ProLiant DL380 G7 - controller HP Smart Array P410i after disk 2014.09.0 SPP / hpsa - 5.0.0.74 update

  Hello

  We are currently investigating massive data store and the problems of latency of disk (mainly READING) on some of our HP ProLiant DL380 G7 with P410i (BBWC) controller.

  It all started after our half of regularly updated cycle for ESXi 5.1 U2 to:

  ESXi510-201407001 (no problem)

  -hp - esxi5.0uX - bundle - 2.1.1 - 2 (no problem)

  -HP-HPUtil-esxi5.0-bundle-2.1-15 (no problem)

  -hpsa - 5.0.0.74 (pilot) & SPP2014.09.0 (-assigned problems)

  It is not a permanent increase in the latency of reading, but rather meeting points that trigger alerts of Veeam. Store of data read latency increases about 5 MS to 100 ms as soon as this happens, but after a few seconds, everything is back to normal. These data warehouses special are RAID5 (but we have also seen some alerts on RAID1), having read and write cache enabled and the most affected machines are those with the LOWEST its use.

  We have a few WinServer2012R2 RDP for a small number of sessions (less than 5) - there is no noticeable delay on work on these.

  Maybe someone of you knows a similar behavior after you apply the updates of HP ProLiant servers. We don't have any idea on what to try next, a SPP restoration is not possible, maybe the pilot, but we find the correct predecessor, as the old drivers of 2014 HPSA leads the Group on the host computer.

  Best regards

  HZ

  Hello

  most likely, you have already solved the problem... I did some research and was in contact with HP. It is a problem with the driver hpsa - 5.0.0.74. It occasionally crashes when used with P410i. In the papers, you can find "WARNING: LinScsi: SCSILinuxAbortCommands:1843: failure, pilot hpsa to vmhba0. HP knows talking and working on the new driver. As a workaround, you can use hpsa - 5.5.0.60 (at least it works well for us).

  BR

  Maachah

• How to export data from disk latency?

  I want to the latency of disk order data in CSV or XLS format but could not find a way to export.  Its not included in the existing reports.  I can view the data in a nice graph, but I can't go to the numbers.

  Anyone know if this is possible?

  Thank you

  

  Go to the section "all indicators; Locate this same metric and view it (choose the period that interests us).

  There, you have the ability to save data in CSV or PNG.
  I've attached a snapshot.

• Acceptable DELL PS4100xv and SAN HQ disk performance

  Hello

  I have a Dell PS4100xv with 12 x 600 GB 15K SAS drives configured in RAID 6.

  3 three R420 servers are connected via 2 x Power Connect 6224 (bunk).

  I'm under ESXi 5.1 U1 with a mixture of SQL virtual computers, file servers, and Proxy servers.

  What are the acceptable values for a healthy EQL in terms of latency, disk queue, Ops ARE / s and etc?

  Just recently, I transferred a virtual machine to the PS4100XV. The virtual machine has a very slow behavior when using the EQL Dell. This is SQL Server. You have a lot of users complaining about the sluggish behavior.

  I need to determine if I have a problem on my PS4100xv in terms of performance before you start to troubleshoot the VMs and ESXi hosts.

  These are values measured HQ SAN during the last eight hours.

  If I got this right that my own analysis

  • The disk queue is ok, since its constantly @ 0. EQL can handle the load and nothing is pending.

  • IOPS / s is ok, because the base on the RAID my table evaluator should support 1500 IOPs. Current reading is 742 IOPS / s only.

  • To write latency is ok because he is 13 Ms and does not even approach 20 ms.

  • Latency of reading, I have a problem? It fits above 20 Ms flat around 25 ms to 40 ms.      But not more than is not 40 ms.
  • For the size of the IO rate & IO, I don't know if that's a good indicator. What are the acceptable values?

  Disk queue depth:	zero (0), the graph shows his dish to zero.
  Average READ IOPS:	625
  Average WRITE IOPS / s:	117
  Total average IOPS / s	742
  Latency average reading	30 ms (ms 20 to 40 ms)
  Average latency of writing	13 ms (straight line @ 13 ms)
  Weighted average	28 ms
  E/s average rate readings	26.41 MB/sec
  Writing of average IO	2.26 Mbps
  Total	28.67 MB/s
  Average size of READ i/o	43,30 KB
  Average size of i/o WRITE	19.91 KB
  Weighted average	39.62 KB

  There is no retransmission of packets and the network usage is only 3%.

  Would really appreciate the input and recommendations.

  What are the acceptable values for a healthy EQL in terms of latency and IOPS / s, queue disk, etc.?

  Thank you

  Paul

  I strongly suggest you open a record of support on any show of related issues.  However, with ESXi especially when I see low i/o + latency, the first thing I usually find is that DelayedACK is enabled.  Sometimes, large receive the unloading (LRO) can do that as well.   Another common problem is not optimize MPIO.  And not not not using Round Robin with 3 IOs by path from the default value of 1000 IOs.  Or if you have a company or business license + installation Dell EQL MEM.   Sharing also several VMDK with one card virtual SCSI inside each virtual machine is another cause of latency.   Each virtual machine can have up to four 4 virtual SCSI adapters.  With a single adapter, single VMDK (disc) can be active at a given time.  If an operation of e/s on the "C:" drive will block your SQL disks.

  This link is a PDF that will show you how to fix common incorrect configurations with ESXi + EQL.

  en.Community.Dell.com/.../20434601.aspx

  HOWEVER.  If you find delayed ACK is enabled the process described here probably won't be enough to solve the current connections.   With the mode node maint.  Remove the address of discovery EQL, remove the "Static discovery" entries EQL volumes.   Restart the node.   Add discovery addresses but NOT yet rescan.  Make sure that login_timeout is 60 years old, DelayedACK is disabled.   Then make the new analysis.

  Kind regards

• Cisco C240-M4SX / 12G SAS Embedded Raid Controller Queue depth Reporting resulting in ESXi 6.0

  All,

  We have been a customer of vSAN VMware 6.0 for the last 6 months of our environment entirely on servers of Cisco C240 M4SX with the Cisco 12 G SAS integrated Raid Controller.   Everything in the environment was working well until we started to bring in data warehouse loads in the environment and began to notice performance around latency of disk and most important issues still outstanding IO high.  After that ESXtop and ESXCFG examination we found that the length of the queue announced to the adapter ESXi has been only 234 however the VMware HCL Announces 895; 234 is below minimum spec of 256 to correctly implement vSAN.  We have worked diligently with VMware on it to try different versions certified and non certified driver async for this raid controller in addition to the most recent firmware for the raid controller.  Regardless of the change of the depth of the queue remained 234.  The presence of FBWC affect the depth of queue announced to the operating system?  VMware support has indicated that it is clearly a problem "hardware".  Any ideas as to what may be causing this?

  Our environment:

  C240-M4SX

  Integrated 12G SAS Raid Controller (operation JBOD / pass-through, not FBWC)

  UCSM 2.2 (6 c)

  Driver of VMware for controller: 6.606.06.00 - 1OEM.550.0.0.1331820.x86_64.vib

  VMware vSphere 6.0U1

  12 - 28-2015_5-51 - 31_pm.png

  

  12 - 28-2015_5-56 - 51_pm.png

  

  Greetings.

  Had the chance to spend some time in the laboratory and removed the cache module.

  After that, I now get "207", so I would say it's confirmed that 1,2,4 GB cache modules are used to increase the depth/length of the queue for these controllers.

  12gb_sas_qdepth_no_cache.jpg

  

  Thank you

  Kirk