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 V7
rp
RP(4) Kernel Interfaces Manual RP(4)NAME
rp - RP-11/RP03 moving-head disk
DESCRIPTION
The files rp0 ... rp7 refer to sections of RP disk drive 0. The files rp8 ... rp15 refer to drive 1 etc. This allows a large disk to be
broken up into more manageable pieces.
The origin and size of the pseudo-disks on each drive are as follows:
disk start length
0 0 81000
1 0 5000
2 5000 2000
3 7000 74000
4-7 unassigned
Thus rp0 covers the whole drive, while rp1, rp2, rp3 can serve usefully as a root, swap, and mounted user file system respectively.
The rp 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 RP files begin with rrp and end with a number which selects the same disk section as the corresponding
rp file.
In raw I/O the buffer must begin on a word boundary.
FILES
/dev/rp?, /dev/rrp?
SEE ALSO hp(4)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.
RP(4)