Hi, On Thu, 21 May 1998, misc.word.corp wrote:
I'm running SuSE 5.2 on my PII box, and, whenever I do a hard reset (due to a KDE lockup, etc.) , I get the following error message during the reboot, as Linux looks at each of my partitions (which were not umounted cleanly):
/hda8 (0.8 on-contiguous) /hda9 (10.8on-contiguous) etc.
My HD is divided into /tmp, /usr, /opt, /, and /home partitions, but only /usr (due to its humongeous size, I guess) is showing fragmentation over 1%). It's now at 10.8%, and getting more fragmented by the day.
Any M---S---T operating system would need to be defragged at this point, of course. Linux seems to be tolerating the fragmentation well -- I've been told that it's okay to ignore it -- but apps loading from /usr are slowing down.
Are you sure you can see a slowdown? I think most of the fragmentation on /usr comes from compiling the kernel. The installation wrote the apps to a freshly formatted partition so they shouldn't be fragmented at all. This may not be true for applications installed after a kernel compile but fragmentation really shouldn't be a problem. Please note that when you execute some binary, not the whole binary is loaded into memory, but only the pages that currently need to be executed. In the meantime some other program might need some data from somewhere else on the disk, so fragmentation itself is not as much a problem as under DOS.
Does anybody have background on what to do about fragmented HDs?
Nothing. Just ignore it. Fragmentation only can become a problem on almost full partitions.
Has anybody defragged a drive using the defrag utility available at RedHat or elsewhere?
I wouldn't dare.
All fragmentation and defrag stories appreciated!!
A partition on a Linux system has some "normal fragmentation level" which depends on the type of partition. A /usr or /opt partition which mainly holds binaries will not be fragmented very much. Partitions that are written often will get somewhat fragmented after some time, but defragmenting doesn't help that much, because after some time they will be fragmented again. Please note that the ext2fs code has some sort of fragmentation avoidance built in: If two processes are writing to the same partition at the same time, they DO NOT generate the pattern ABABABAB, but AAAABBBB because the filesystem code does some pre-allocation of blocks to avoid the fragmentation. The only way I would defragment a partition is: Backup all the data, create a new filesystem and restore the data. But I never did it as I consider it unnecessary.
-- Glenn --
Hubert -- To get out of this list, please send email to majordomo@suse.com with this text in its body: unsubscribe suse-linux-e