Hi you all, I have a BIG performance problem on an Sun E3500, the scenario is described below:
I have several users (30) accessing via samba to the E3500 using an application built on Visual Foxpro from their Windows PC , the problem is that the first guy that logs in demands 30% of the E3500... (2 Replies)
Hello,
i have a a1000 connected to an e6500. There's a raid 10 (12 disks) on the a1000.
If i do a
dd if=/dev/zero of=/mnt/1 bs=1024k count=1000
and then look at iostat it tells me there's a kw/s of 25000.
But if i do a
dd of=/dev/zero if=/mnt/1 bs=1024k count=1000
then i see only a... (1 Reply)
Hello,
I'm running a script on AIX to process lines in a file. I need to enclose the second column in quotation marks and write each line to a new file. I've come up with the following:
#!/bin/ksh
filename=$1
exec >> $filename.new
cat $filename | while read LINE
do
echo $LINE | awk... (2 Replies)
Hello all
We just built a storage cluster for our new xenserver farm. Using 3ware 9650SE raid controllers with 8 x 1TB WD sata disks in a raid 5, 256KB stripe size.
While making first performance test on the local storage server using dd (which simulates the read/write access to the disk... (1 Reply)
Hello,
we have a machine with Solaris Express 11, 2 LSI 9211 8i SAS 2 controllers (multipath to disks), multiport backplane, 16 Seagate Cheetah 15K RPM disks.
Each disk has a sequential performance of 220/230 MB/s and in fact if I do a
dd if=/dev/zero of=/dev/rdsk/<diskID_1> bs=1024k... (1 Reply)
Hello guys,
I have two servers performing the same disk operations. I believe one server is having a disk's impending failure however I have no hard evidence to prove it. This is a pair of Netra 210's with 2 drives in a hardware raid mirror (LSI raid controller). While performing intensive... (4 Replies)
Hi,
I am new registered user here in this UNIX forums.
I am a new system administrator for AIX 6.1. One of our servers performs poorly every time our application (FINACLE) runs many processes/instances. (see below for topas snapshot)
I use NMON or Topas to monitor the server utilization. I... (9 Replies)
Hi
We have an M3000 single physical processor and 8gb of memory running Solaris 10. This system runs two Oracle Databases one on Oracle 9i and One on Oracle 10g.
As soon as the Oracle 10g database starts we see an immediate drop in system performance, for example opening an ssh session can... (6 Replies)
Just a quick note for macOS users.
I just installed (and removed) Parallels Desktop 15 Edition on my MacPro (2013) with 64GB memory and 12-cores, which is running the latest version of macOS Catalina as of this post. The reason for this install was to test some RIGOL test gear software which... (6 Replies)
Discussion started by: Neo
6 Replies
LEARN ABOUT CENTOS
blockdev
BLOCKDEV(8) System Administration BLOCKDEV(8)NAME
blockdev - call block device ioctls from the command line
SYNOPSIS
blockdev [-q] [-v] command [command...] device [device...]
blockdev --report [device...]
DESCRIPTION
The utility blockdev allows one to call block device ioctls from the command line.
OPTIONS -V Print version and exit.
-q Be quiet.
-v Be verbose.
--report
Print a report for the specified device. It is possible to give multiple devices. If none is given, all devices which appear in
/proc/partitions are shown. Note that the partition StartSec is in 512-byte sectors.
COMMANDS
It is possible to give multiple devices and multiple commands.
--flushbufs
Flush buffers.
--getalignoff
Get alignment offset.
--getbsz
Print blocksize in bytes.
--getdiscardzeroes
Get discard zeroes support status.
--getfra
Get filesystem readahead in 512-byte sectors.
--getiomin
Get minimum I/O size.
--getioopt
Get optimal I/O size.
--getmaxsect
Get max sectors per request
--getpbsz
Get physical block (sector) size.
--getra
Print readahead (in 512-byte sectors).
--getro
Get read-only. Print 1 if the device is read-only, 0 otherwise.
--getsize64
Print device size in bytes.
--getsize
Print device size (32-bit!) in sectors. Deprecated in favor of the --getsz option.
--getss
Print sectorsize in bytes - usually 512.
--getsz
Get size in 512-byte sectors.
--rereadpt
Reread partition table
--setbsz bytes
Set blocksize. Note that the block size is specific to the current file descriptor opening the block device, so the change of block
size only persists for as long as blockdev has the device open, and is lost once blockdev exits.
--setfra sectors
Set filesystem readahead (same like --setra on 2.6 kernels).
--setra sectors
Set readahead (in 512-byte sectors).
--setro
Set read-only.
--setrw
Set read-write.
AUTHOR
blockdev was written by Andries E. Brouwer and rewritten by Karel Zak.
AVAILABILITY
The blockdev command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
util-linux August 2010 BLOCKDEV(8)