Slow Copy(CP) performance Post: 302359552

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Special Forums Hardware Filesystems, Disks and Memory Slow Copy(CP) performance Post 302359552 by zxmaus on Wednesday 7th of October 2009 12:56:18 AM

10-07-2009

Moderator

Since you don't tell us anything about your OS, your disklayout or anything else, we obviously have to guess, but in any case a copy from A to B that is slow is rather an IO issue than a cpu problem.
My best guess is, that both filesystems are maybe on the same disk and have maybe even different blocksizes. Since your filesystem was almost full, your fragmentation is very likely very high, since the OS had to put additional data where space were left, so typically the data was spread across the remaining diskspace and not nicely lined up like it would have been the case with lots of free space in the volumegroup. And I assume you haven't done a defragfs after cleaning up your diskspace.
When you now copy data from A to B and both locations are on the same disk, your system will take a lot more time to 1. find the data in the 'correct' order in filesystem A and read it - because its spread across the physical volume and 2. it will take a lot of time put the data back to disk in filesystem 'B' in the correct and suitable order - since the system has to find again free blocks big enough for your data chunks - and these chunks are likely as well spread across the entire disk.
Try to defrag your diskspace a few times, maybe that improves performance. If not, backup your data, drop the filesystems, defrag, recreate them and restore the content from backups.

Kind regards
zxmaus

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mhpath

mhpath(1)						      General Commands Manual							 mhpath(1)

NAME

       mhpath - print full pathnames of MH messages and folders (only available within the message handling system, mh)

SYNOPSIS

       mhpath [+foldername] [msgs] [-help]

OPTIONS

       Prints a list of the valid options to this command.

DESCRIPTION

       Use  the  mhpath command to display the full pathname of the specified folder. If you do not specify a folder, mhpath displays the pathname
       of the current folder.

       If you specify a message with its message number, mhpath displays the pathname of the specified message. You can also specify a	number	of
       messages,  or a range of messages. If the top of the range that you specify is greater than the last message in the folder, mhpath displays
       as much of the specified range as possible.

       Additionally mhpath can take a keyword or a sequence name. The following keywords are acceptable: The first message  in	the  folder.   The
       last  message in the folder.  The message after the last message in the folder. You cannot use new as part of a message range.  The current
       message in the folder.  The message before the current message.	The message after the current message.	All of the messages in the folder.

PROFILE COMPONENTS

       Path: To determine your Mail directory

EXAMPLES

       In the following example, mhpath displays message 3 in the folder +inbox: % mhpath +inbox 3 /r/phyl/Mail/inbox The following  example  dis-
       plays  the  pathname  of messages 2 to 5 in the current folder: % mhpath 2-5 /r/phyl/Mail/inbox/2 /r/phyl/Mail/inbox/3 /r/phyl/Mail/inbox/4
       /r/phyl/Mail/inbox/5

FILES

       The user profile.

SEE ALSO

       folder(1)

																	 mhpath(1)