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Questions tagged [io]

IO (or I/O) is an abbreviation for input/output, most commonly referring to disk input/output.

IO (or I/O) is an abbreviation for input/output, most commonly referring to disk input/output.

401 questions
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Do I need to create multiple filesystems on a virtual server to increase I/O performance?

I want to install Oracle on a virtual server. I don't really know the technology behind, my company just gave me a virtual server with multiple (virtual) disks. I have the possibility to divide those disks into multiple logical volumes to partition…
Pierre
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what is snmp mib for getting NFS IO counters?

I can get local disk I/O requests and read/write bytes using the following snmp MIB: SNMP table: UCD-DISKIO-MIB::diskIOTable diskIOIndex diskIODevice diskIONRead diskIONWritten diskIOReads diskIOWrites diskIOLA1 diskIOLA5 diskIOLA15 diskIONReadX…
GP92
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Why is my btrfs/dm-crypt RAID1 setup so slow?

I have a system that's set up with a four-disk RAID1 array based on btrfs. Two disks are 1TB traditional HDDs, and the other two are 128GB SSDs. Most of each disk is filled up with a LUKS container. Inside all four LUKS containers I have a single…
strugee
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Disk IO Rate: What causes it and what does it mean to me?

I just got a mail from Linode saying that my account "has exceeded the notification threshold (1000) for disk io rate by averaging 1017.36 for the last 2 hours. " My question is just out of curious: From the literal meaning, disk io rate must mean…
shenkwen
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Restrict I/O Write usage using cgroups

I am trying to restrict I/O write usage on my server using cgroups. Here is my partition table info: major minor #blocks name 8 0 10485760 sda 8 1 9437184 sda1 8 2 1047552 sda2 Here is my Filesystem…
Divij Satra
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Show IO on Netapp

I think I might be hitting the IO limits of what my Netapp can deliver, as I have been adding more servers to my cluster and iowait has gone up on each server. However, how do I quantify this? How can I use Netapp CLI tools to view current IO stats?…
cat pants
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How can I monitor disk IO load on a Windows 2008 server?

We are running multiple processes on our servers, which are mostly CPU intensive, but also use the local HDDs for reading the data. I can trivially look at the CPU load and memory usage in TaskManager on these boxes, how can I monitor the HDD IO? I…
Grzenio
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Does changing /sys/block/sda/queue settings take effect immediately?

How long does it take for changes to the following settings to take effect: /sys/block/sda/queue/scheduler /sys/block/sda/queue/rotational /sys/block/sda/queue/read_ahead_kb Is it immediately/with a few seconds, or does it require the process to…
stephenbez
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Is it possible to configure the Linux kernel I/O scheduler for an NFS mount?

On a normal block device you can change the i/o scheduler like this: # cat /sys/block/hda/queue/scheduler noop anticipatory deadline [cfq] # echo anticipatory > /sys/block/hda/queue/scheduler # cat /sys/block/hda/queue/scheduler noop [anticipatory]…
Robert Swisher
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Azure IO performance

We have a number of Windows Server virtual machines that we use for .NET and Java development and QA. I find Azure attractive for the obvious reasons but mainly for the opportunity to reduce non-productive hours spent on environmental…
BigTFromAZ
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Setting I/O scheduler for SSD based RAID array on EC2 instances

I created a RAID array using the 2 local SSD drives on a EC2 c3.4xlarge instance. # mdadm --create /dev/md127 --level=0 --raid-devices=2 /dev/xvdf /dev/xvdg # mkfs.ext4 /dev/md127 # mkdir /data # echo 'DEVICE /dev/xvdf /dev/xvdg' > /etc/mdadm.conf #…
BraveHeart
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Does ESX 5.X cache guest IO?

I am trying to find out if guest can see successful disk flush operation, but the host doesn't actually flush it to disk? How does ESXi work with guest I/O? Are they cached by ESXi before being written to the host's disk?
funny_sailor
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I/O priority per LVM volume (cgroups)

How can I prioritize LVM volumes I/O performance using cgroups? I know I can use ionice to make changes at the process level but I wish to be able to do this per LV and not per process.
ApriOri
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IO related performance bottleneck on a LAMP server

I am administering a big LAMP server with some thousand users. About a week ago, things slowed down, and the only thing I see that the IO latency is increased dramatically. Users experience slow page loads, and I experience seconds of hanging when I…
hgj
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High await in sar

My database server has the following sar output for the data device: [postgres@dbsrv07 ~]$ LC_ALL=POSIX sar -d |egrep "await|dev253-2" 00:00:01 DEV tps rd_sec/s wr_sec/s avgrq-sz avgqu-sz await svctm %util 00:10:01 …
xpapad
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