Code: Select all
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sda -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:0/end_device-0:0:0/target0:0:0/0:0:0:0/block/sda
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdb -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:1/end_device-0:0:1/target0:0:1/0:0:1:0/block/sdb
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdc -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:2/end_device-0:0:2/target0:0:2/0:0:2:0/block/sdc
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdd -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:3/end_device-0:0:3/target0:0:3/0:0:3:0/block/sdd
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sde -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:4/end_device-0:0:4/target0:0:4/0:0:4:0/block/sde
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdf -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:5/end_device-0:0:5/target0:0:5/0:0:5:0/block/sdf
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdg -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:7/end_device-0:0:7/target0:0:7/0:0:7:0/block/sdg
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdh -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:8/end_device-0:0:8/target0:0:8/0:0:8:0/block/sdh
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdi -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:6/end_device-0:0:6/target0:0:6/0:0:6:0/block/sdi
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdj -> ../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/port-0:0/expander-0:0/port-0:0:9/end_device-0:0:9/target0:0:9/0:0:9:0/block/sdj
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdk -> ../devices/pci0000:00/0000:00:1f.2/ata1/host1/target1:0:0/1:0:0:0/block/sdk
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdl -> ../devices/pci0000:00/0000:00:1f.2/ata2/host2/target2:0:0/2:0:0:0/block/sdl
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdm -> ../devices/pci0000:00/0000:00:1f.2/ata3/host3/target3:0:0/3:0:0:0/block/sdm
lrwxrwxrwx 1 root root 0 Jan 6 11:15 sdn -> ../devices/pci0000:00/0000:00:1f.2/ata4/host4/target4:0:0/4:0:0:0/block/sdn
DEVICE=sdX # insert your device name here
echo 3600 > /sys/block/$DEVICE/device/timeout
echo 3600 > /sys/block/$DEVICE/device/eh_timeout
echo noop > /sys/block/$DEVICE/queue/scheduler
echo 1 > /sys/block/$DEVICE/device/queue_depth
echo 4 > /sys/block/$DEVICE/queue/nr_requests
timeout
default: 30
timeout in seconds.
io_timeout
default: 30
io_timeout is the request timeout in milliseconds. If a request does not complete in this time then the block driver timeout handler is invoked. That timeout handler can decide to retry the request, to fail it or to start a device recovery strategy.
eh_timeout
default: 10
timeout in seconds. eh_timeout has been added to the SCSI device object, which allows configuration of the timeout value for TEST UNIT READY and REQUEST SENSE commands used by the SCSI error handling code. This decreases the amount of time spent checking these unresponsive devices.
scheduler
default: [mq-deadline] none
I/O schedulers exist as a way to optimize disk access requests. When read, this file will display the current and available IO schedulers for this block device. The currently active IO scheduler will be enclosed in [] brackets. Writing an IO scheduler name to this file will switch control of this block device to that new IO scheduler. Note that writing an IO scheduler name to this file will attempt to load that IO scheduler module, if it isn't already present in the system.
https://www.cloudbees.com/blog/linux-io ... ler-tuning
queue_depth
default: 32
The queue_depth determines the maximum number of concurrent I/Os written to the block device. In Linux, the default value is 128. Do not change the value unless absolutely necessary. To query the queue depth of the block device, run cat.
nr_requests
default: 64
This controls how many requests may be allocated in the block layer for read or write requests. Note that the total allocated number may be twice this amount, since it applies only to reads or writes (not the accumulated sum).
To avoid priority inversion through request starvation, a request queue maintains a separate request pool per each cgroup when CONFIG_BLK_CGROUP is enabled, and this parameter applies to each such per-block-cgroup request pool. IOW, if there are N block cgroups, each request queue may have up to N request pools, each independently regulated by nr_requests.