All,
I am attempting to help tune a Sun for better performance (mainly for SAS 9.1), and have found indicators pointing to poor I/O utilization. I have run iostat -cx, and found one device in particular where the %w is in the 90's during processing. I have a feeling that this is where the SAS... (3 Replies)
I'm search for a disk exerciser / load tool like iometer, iozone, diskx for IBM AIX 5.2 and 5.3
Because of a very bad disk performance on several AIX systems, I need to have a tool which is able to generate a disk load on my local and SAN disks.
Does somebody knows a kind of tool which is... (5 Replies)
Friends.
I have to compare iostat -x output with a tool on solaris. Now there is column called wait in the output field which is showing zero. Now, in order to create some load on my system this is what i am doing
I am creating a file using dd command , the size of which is... (5 Replies)
Hello,
On Solaris 10, iostat -E gives me the following results:
sd1 Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: FUJITSU Product: MAY2073RCSUN72G Revision: 0501 Serial No: 0708S08M2L
Size: 73.40GB <73400057856 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0... (1 Reply)
Hi, can anyone please suggest a tool to dump i/o packets just like tcpdump does for network traffic. Basically I have a complex dataflow that needs to be optimized and I want to see how packets go to/from disk - what goes randomly and sequentially.
Thanks (8 Replies)
A find for the "iostat" command on a redhat 5 update 4 comes back with no results.
Any separate rpm needs to be installed to get the binary for this ?
Thanks in advance. (1 Reply)
Writing a Tool to simulate non-sequential disk I/O (simulate db file sequential read) in C POSIX
I have over the years come across the same issue a couple of times, and it normally is that the read speed on SAN is absolutely atrocious when doing non-sequential I/O to the disks. Problem being of... (7 Replies)
Hello everyone,
Can you please explain me what kind of information do IOSTAT show ?
iostat -xnz 3 show me those informations:
The I/O of the c0t0d0 disk is normal ?
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
0.0 ... (3 Replies)
Hello, I support Oracle 11g on AIX 7.1.
Using the command
$iostat -D hdisk2 hdisk4 hdisk5 5
I get the following output:
hdisk5 xfer: %tm_act bps tps bread bwrtn
44.0 1.4M 178.2 1.4M 14.7K
read: ... (3 Replies)
Hi Everyone,
I try to calculate the total hard disk space of a solaris machine using iostat -En command. Iterating the output and summing up all the number present near the Size: will give the exact size of the harddisk. But it is not working for a machine.
This command works in many flavors... (2 Replies)
Discussion started by: prasankn
2 Replies
LEARN ABOUT ULTRIX
scsi
SCSI(4) Kernel Interfaces Manual SCSI(4)Name
SCSI - Small Computer System Interconnect
Description
The ULTRIX system interfaces to disk and tape devices through the Small Computer System Interconnect (SCSI). Initial ULTRIX SCSI support
is limited to the Digital-supplied mass storage devices. The following devices are fully supported on the ULTRIX system:
o Winchester disks: RZ22, RZ23, RZ23L, RZ24, RZ55, RZ56, RZ57, RX23, RX26, RX33
o Magnetic tapes: TZ30, TZK50, TLZ04, TSZ05, TKZ08, TZK10
o Optical disks: RRD40, RRD42
Under the ULTRIX operating system, a SCSI device is referred to by its logical name. Logical names take the following form:
nn#
The nn argument is the two-character name; the number sign (#) represents the unit number. The two character names for SCSI devices are:
rz - RZ22, RZ23, RZ23L, RZ24, RZ55, RZ56, RZ57, RX23, RX26, RX33, RRD40, RRD42 disks
tz - TZ30, TZK50, TLZ04, TSZ05, TKZ08, and TZK10 tapes
The unit number is a combination of the SCSI bus number, either 0, 1, ... and the device's target ID number. The unit number is eight
times the bus number plus the target ID. For example, an RZ23 disk at target ID 3 on bus 0 would be referred to as rz3; a TZK50 tape at
target ID 5 on the second SCSI bus would be referred to as 13.
The SCSI bus has eight possible target device IDs. By default, one is allocated to the system. This allows for a maximum of seven target
devices connected to a SCSI bus.
Restrictions
The ULTRIX SCSI device driver does not operate with optical disks, other than the Digital-supplied devices.
The SCSI driver attempts to support on a best effort basis, non-Digital-supplied winchester disks and magnetic tapes.
The following notes apply to the driver's handling of non-Digital-supplied disks:
o These disks are assigned a device type of RZxx, instead of RZ22, RZ23, RZ23L, RZ55, RZ56, RZ57, RX23, RX26, or RX33. The RZxx disks
follow the same logical device naming scheme as the Digital-supplied disks.
o During the autoconfigure phase of the system startup, the driver prints the contents of the SCSI vendor ID, product ID, and the
revision level fields of the inquiry data return by the SCSI device.
o RZxx disks are assigned a default partition table. The default table can be modified by editing the sz_rzxx_sizes[8] entry in the
file The utility can also be used to modify the partition table on a RZxx disk.
o The only logical unit number (LUN) supported for each target ID is 0.
See Alsorz(4), tz(4), chpt(8)SCSI(4)