That will be inaccurate because of cache... stuff written to disk just gets shoved into memory until the disk's ready. 30 gigs would probably fill the cache, but still, there's better ways that don't involve waiting for 30 gigs of data to be written.
Linux usually has the hdparm command. It has read tests that take just a few seconds:
There's no equivalent write-speed test but, for a traditional hard disk, read speed and write speed should be about the same.
If a file size increases in Linux/UNIX to say in GB's then will there be a decrease in write speed.
I mean will it take more time to write to a large file then to a small one??
Please clarify?
Thanks in advance (2 Replies)
I analysed disk performance with blktrace and get some data:
read:
8,3 4 2141 2.882115217 3342 Q R 195732187 + 32
8,3 4 2142 2.882116411 3342 G R 195732187 + 32
8,3 4 2144 2.882117647 3342 I R 195732187 + 32
8,3 4 2145 ... (1 Reply)
Hi,
We have smb client running on two of the linux boxes and smb server on another linux system. During a backup operation which uses smb, read of a file was allowed while write to the same file was going on.Also simultaneous writes to the same file were allowed.Following are the settings in the... (1 Reply)
Would simply like to write data (no audio) to a CD/RW disk. The disk drive states CD/RW on the front but don't know for sure if the software is configured to recognize it as a writable disk. I can read/move data from the disk to the hard drive with no issue from the disk. Any help in this... (4 Replies)
I am now on Kernel 2.6.32-26
For me 16x CD write speed is okay.
I have old hardware which was able to write DVDs at 1x, back in previous linux version.
Now, I dont get speed of less than 4x.
Tested on k3b, xfburn, and brasero. But all start at bottom 4x write speed. k3b forced back to... (0 Replies)
Hi,
I went to a computer store and the salesman sold me a SATA cable and told me that all SATA cables are the same. Another salesman at a different store told me a cable rated for SATA 2, which I bought, MIGHT work as well as one rate for SATA 3 but it is not guaranteed. I decided to run a... (3 Replies)
hi all:
as we know , when usb flash disk plug in and aotu mounted , the default permission of the usb flash disk is 700. that means others have no permission . the question: how to make others have read/write permission when the aotu mounted usb flash disk pluge in ? thanks !! (0 Replies)
Hi,
We have two servers in scenario (vmsoldot01 is Oracle VM with Linux and tldtppod15 is physical Linux server). One NAS share is mounted on both servers with similar permissions and access. But READ speed is too bad on virtual in comparison to physical server.
While trying to diagnose this, I... (2 Replies)
Hello All,
I am building a real time parser for a log file in my application.
The log file is continuously written at a very fast pace and gets rolled over every 10 minutes.
I have measured the speed and observed that around 1000 lines are written to it every second, each line about 30-40... (7 Replies)
Discussion started by: cool.aquarian
7 Replies
LEARN ABOUT DEBIAN
partx
PARTX(8) System Administration PARTX(8)NAME
partx - tell the Linux kernel about the presence and numbering of on-disk partitions
SYNOPSIS
partx [-a|-d|-s] [-t TYPE] [-n M:N] [-] disk
partx [-a|-d|-s] [-t TYPE] partition [disk]
DESCRIPTION
Given a device or disk-image, partx tries to parse the partition table and list its contents. It optionally adds or removes partitions.
The disk argument is optional when a partition argument is provided. To force scanning a partition as if it were a whole disk (for example
to list nested subpartitions), use the argument "-". For example:
partx --show - /dev/sda3
This will see sda3 as a whole-disk rather than a partition.
This is not an fdisk program -- adding and removing partitions does not change the disk, it just tells the kernel about the presence and
numbering of on-disk partitions.
OPTIONS -a, --add
Add the specified partitions, or read the disk and add all partitions.
-b, --bytes
Print the SIZE column in bytes rather than in human-readable format.
-d, --delete
Delete the specified partitions or all partitions.
-g, --noheadings
Do not print a header line.
-l, --list
List the partitions. Note that all numbers are in 512-byte sectors. This output format is DEPRECATED in favour of --show. Don't
use it in newly written scripts.
-o, --output list
Define the output columns to use for --show and --raw output. If no output arrangement is specified, then a default set is used.
Use --help to get list of all supported columns.
-r, --raw
Use the raw output format.
-s, --show
List the partitions. All numbers (except SIZE) are in 512-byte sectors. The output columns can be rearranged with the --output
option.
-t, --type type
Specify the partition table type -- aix, bsd, dos, gpt, mac, minix, sgi, solaris_x86, sun, ultrix or unixware.
-n, --nr M:N
Specify the range of partitions. For backward compatibility also the format <M-N> is supported. The range may contain negative
numbers, for example "--nr :-1" means the last partition, and "--nr -2:-1" means the last two partitions. Supported range specifi-
cations are:
<M> Specifies just one partition (e.g. --nr 3).
<M:> Specifies lower limit only (e.g. --nr 2:).
<:N> Specifies upper limit only (e.g. --nr :4).
<M:N> or <M-N> Specifies lower and upper limits (e.g. --nr 2:4).
EXAMPLES
partx --show /dev/sdb3
partx --show --nr 3 /dev/sdb
partx --show /dev/sdb3 /dev/sdb
All three commands list partition 3 of /dev/sdb.
partx --show - /dev/sdb3
Lists all subpartitions on /dev/sdb3 (the device is used as whole-disk).
partx -o START -g --nr 3 /dev/sdb
Prints the start sector of partition 5 on /dev/sda without header.
partx -o SECTORS,SIZE /dev/sda5 /dev/sda
Lists the length in sectors and human-readable size of partition 5 on /dev/sda.
partx --add --nr 3:5 /dev/sdd
Adds all available partitions from 3 to 5 (inclusive) on /dev/sdd.
partx -d --nr :-1 /dev/sdd
Removes the last partition on /dev/sdd.
SEE ALSO addpart(8), delpart(8), fdisk(8), parted(8), partprobe(8)AUTHORS
Davidlohr Bueso <dave@gnu.org>
Karel Zak <kzak@redhat.com>
The original version was written by Andries E. Brouwer <aeb@cwi.nl>.
AVAILABILITY
The partx command is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
util-linux February 2011 PARTX(8)