10-10-2010
Hai Roland. Is there a problem? What is your problem? It is normal that you get higher throughput with large block sizes. 44 MB/s sequential write performance with a 512 byte block size directly to a device (no write combining) seems pretty decent to me. Is it much larger than the write cache of the controller? What were you expecting?
9 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
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)
Discussion started by: alex blanco
2 Replies
2. Filesystems, Disks and Memory
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)
Discussion started by: mbrenner
1 Replies
3. UNIX for Dummies Questions & Answers
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)
Discussion started by: scooter53080
2 Replies
4. Solaris
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)
Discussion started by: golemico
1 Replies
5. Solaris
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)
Discussion started by: s ladd
4 Replies
6. AIX
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)
Discussion started by: guzzelle
9 Replies
7. Solaris
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)
Discussion started by: gregsih
6 Replies
8. AIX
Hi Everyone,
I have been struggling for few days with iSCSI and thought I could get some help on the forum...
fresh install of AIX7.1 TL4 on Power 710, The rootvg relies on 3 SAS disks in RAID 0, 32GB Memory
The lpar Profile is using all of the managed system's resources.
I have connected... (11 Replies)
Discussion started by: frenchy59
11 Replies
9. Windows & DOS: Issues & Discussions
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
RK(4) Kernel Interfaces Manual RK(4)
NAME
rk - RK-11/RK05 disk
SYNOPSIS
/sys/conf/SYSTEM:
NRK rk_drives # RK05
/etc/dtab:
#Name Unit# Addr Vector Br Handler(s) # Comments
rk ? 177400 220 5 rkintr # rk05
major device number(s):
raw: 15
block: 6
minor device encoding:
specifies drive: <rk_drive>
DESCRIPTION
Minor device numbers are drive numbers on one controller. The standard device names begin with ``rk'' followed by the drive number and
then the letter "h". The character ? stands here for a drive number in the range 0-7.
The block files access the disk via the system's normal buffering mechanism and may be read and written without regard to physical disk
records. There is also a `raw' interface which provides for direct transmission between the disk and the user's read or write buffer. A
single read or write call results in exactly one I/O operation and therefore raw I/O is considerably more efficient when many words are
transmitted. The names of the raw files conventionally begin with an extra `r.'
In raw I/O the buffer must begin on a word (even) boundary, and counts should be a multiple of 512 bytes (a disk sector). Likewise seek
calls should specify a multiple of 512 bytes.
DISK SUPPORT
The rk driver does not support pseudo-disks (partitions). Each file rk?h refers to the entire drive as a single sequentially addressed
file. Each drive has 4872 512-byte blocks.
It's not clear what one would do with one of these drives if one had one ...
FILES
/dev/rk[0-7]h block files
/dev/rrk[0-7]h raw files
/dev/MAKEDEV script to create special files
/dev/MAKEDEV.local script to localize special files
SEE ALSO
hk(4), ra(4), ram(4), rl(4), rp(4), rx(4), si(4), xp(4), dtab(5), autoconfig(8)
DIAGNOSTICS
rk%d: hard error sn%d er=%b ds=%b. An unrecoverable error occurred during transfer of the specified sector of the specified disk. The
contents of the two error registers are also printed in octal and symbolically with bits decoded. The error was either unrecoverable, or a
large number of retry attempts could not recover the error.
rk%d: write locked. The write protect switch was set on the drive when a write was attempted. The write operation is not recoverable.
BUGS
In raw I/O read and write(2) truncate file offsets to 512-byte block boundaries, and write scribbles on the tail of incomplete blocks.
Thus, in programs that are likely to access raw devices, read, write and lseek(2) should always deal in 512-byte multiples.
DEC-standard error logging should be supported.
A program to analyze the logged error information (even in its present reduced form) is needed.
3rd Berkeley Distribution August 20, 1987 RK(4)