defrag the system drive
- Thread starter dr fletch
- Start date
Defrag isn't really for much use in OS X unless you severely abuse your system (creating and deleting huge files all the time several times a day of different sizes, for months or years, without any maintenance).
What was the original issue you were trying to fix wih dw?
What was the original issue you were trying to fix wih dw?
DW suggests I rebuild the system directory before installing it on the Mac (G4), but when I try it says I cannot as it's too badly damaged. No other explaination is offered. i'm merely concerned that it has 'issues'.
ex2bot
Registered Bot
I have iDefrag, and it works VERY well if you keep it in perspective. Dr. Fletch, it's probably not going to help your scrambled data. You need to reformat your hard drive and restore your data from backups. If you don't have backups, there are are some steps you can take to recover your data.
If you have two Macs, search this site ("Search" on the dark blue strip above) or Google for "Firewire Target Disk Mode". Use it to try and recover important data. Start up the computer with the damaged hard drive holding down T. Connect the two with a Firewire cable that has the correct ends. The scrambled drive will hopefully show up as a disk on the other Mac's desktop.
If you have a bootable external drive, install OS X on it. Boot from the external drive by restarting and holding down the Option key. Select the external drive. The internal drive may mount on the Desktop. if so, try to copy important data off it to your backup drive.
Or try the commercial Data Rescue II by ProSoft Engineering. I've heard good things about it.
The best thing to do is back up your data BEFORE your disk gets scrambled. I hope you did.
Good luck!
--------------------------
More info on iDefrag:
It's good for defragging a disk that has been used for quite awhile, especially if you download a lot of stuff from the Internet or use big audio and video files. If you defrag monthly, for example, you're probably not going to notice a performance benefit month to month.
iDefrag optimizes the hard drive in addition to defragging it. Go to their website, login and download the Coriolis CD Maker. It will put your iDefrag on a CD. Boot from the CD by restarting the computer and holding down C.
Good software, good interface. Worth $30 to me, at least. I use it once every 6 months or so on my multiple machines. BTW, OS X does defrag its drives automatically, but only files smaller than 20 megs (I believe). It's nowhere near as thorough as iDefrag.
Caution: Defragging is, by nature, a bit risky. Back up your valuable data before defragging. Also, make sure you have the most recent version of iDefrag. Updates are free to registered users (perhaps until they come out with a major new version, I'm not sure).
Doug
If you have two Macs, search this site ("Search" on the dark blue strip above) or Google for "Firewire Target Disk Mode". Use it to try and recover important data. Start up the computer with the damaged hard drive holding down T. Connect the two with a Firewire cable that has the correct ends. The scrambled drive will hopefully show up as a disk on the other Mac's desktop.
If you have a bootable external drive, install OS X on it. Boot from the external drive by restarting and holding down the Option key. Select the external drive. The internal drive may mount on the Desktop. if so, try to copy important data off it to your backup drive.
Or try the commercial Data Rescue II by ProSoft Engineering. I've heard good things about it.
The best thing to do is back up your data BEFORE your disk gets scrambled. I hope you did.
Good luck!
--------------------------
More info on iDefrag:
It's good for defragging a disk that has been used for quite awhile, especially if you download a lot of stuff from the Internet or use big audio and video files. If you defrag monthly, for example, you're probably not going to notice a performance benefit month to month.
iDefrag optimizes the hard drive in addition to defragging it. Go to their website, login and download the Coriolis CD Maker. It will put your iDefrag on a CD. Boot from the CD by restarting the computer and holding down C.
Good software, good interface. Worth $30 to me, at least. I use it once every 6 months or so on my multiple machines. BTW, OS X does defrag its drives automatically, but only files smaller than 20 megs (I believe). It's nowhere near as thorough as iDefrag.
Caution: Defragging is, by nature, a bit risky. Back up your valuable data before defragging. Also, make sure you have the most recent version of iDefrag. Updates are free to registered users (perhaps until they come out with a major new version, I'm not sure).
Doug
Mikuro
Crotchety UI Nitpicker
Defragging does not repair a damaged drive. If your drive is damaged, you need to take other steps. Have you tried repairing the disk in Disk Utility yet? And do Disk Utility or Disk Warrior give you any other information?
It sounds like your system is still working, so I assume the damage isn't too severe. You should back up your important data before doing anything further. That's just good practice.
Generally, defragmenting OS X volumes is more trouble than it's worth. OS X keeps its disks a bit tidier than Windows to start with, so fragmentation doesn't usually become a big issue. There are certainly exceptions to this rule, but unless you're suffering unusual performance hits that you can clearly trace to disk access, I wouldn't bother defragmenting at all.
It sounds like your system is still working, so I assume the damage isn't too severe. You should back up your important data before doing anything further. That's just good practice.
Generally, defragmenting OS X volumes is more trouble than it's worth. OS X keeps its disks a bit tidier than Windows to start with, so fragmentation doesn't usually become a big issue. There are certainly exceptions to this rule, but unless you're suffering unusual performance hits that you can clearly trace to disk access, I wouldn't bother defragmenting at all.
Natobasso
Tech-Bot 5000
OS X utilizes disk space in such a way that it does not need to be defragged. What you do need to do regularly is repair permissions: apps/utilities/disk utility/repair permissions.
Onyx is a great program for this, though you don't absolutely need it on a regular basis. Repair permissions once a month, or so, should suffice. Restart your computer every now and then as well.
Onyx is a great program for this, though you don't absolutely need it on a regular basis. Repair permissions once a month, or so, should suffice. Restart your computer every now and then as well.
bluedevils
Registered
another recently active thread (geek message) confirmed to me that osx has the old unix disk utility fsck. Would this be a solution for you?
bluedevils
Registered
Sorry I didn't make myself clear. Wouldn't fsck be more appropriate than defragging, if he is having hard drive problems? I have never had to defrag a unix machine, but fsck can be helpful correcting filesystem errors.
jbarley
One more, for the road!
A very thorough defragging can be had, if you really feel the need, by cloning your drive to say, an external harddrive.
Then reformatting the drive in question and restoring the clone back onto it.
Each and every file will be laid on in one piece with no spaces between.
Probably the best way to get it done, as most would recommend the backup stage before any attempt to rearrange the files on your disk.
jb.
Then reformatting the drive in question and restoring the clone back onto it.
Each and every file will be laid on in one piece with no spaces between.
Probably the best way to get it done, as most would recommend the backup stage before any attempt to rearrange the files on your disk.
jb.
DeltaMac
Tech
About the fsck question. OS X has Disk Utility, which is a GUI for fsck. A more powerful utility, DiskWarrior, reports problems it cannot repair. So, fsck really is a moot point here. Back up while you can, reformat, and restore to the hard drive, if it is working OK then. Otherwise, replace the HD.
No. Disk Utilities is limited to repairing permissions on your boot volume and to verifying it. It cannot repair the volume itself. If you want to repair your boot volume, you must boot into single-user mode--the Darwin CLI--and type fsck -fy at the command prompt. To accomplish the same thing with Disk Utilities, you must boot from a second volume such as a CD, DVD, or second partition and run DU from there.
Natobasso
Tech-Bot 5000
To run fsck -f:
restart and hold command + s till black screen comes up, then type fsck -f. Type reboot when process is finished.
Kees Buijs
Registered
Defragmentation is used to increase speed by re-arranging files in suc a way that they can be read more quickly. Normally after some time a file may be stored in multiple fragments on different parts of the drive, which will decrease reading speed because the head has to make additional movements). Therefore DEFRAGMENTATION has no consequence for the proper function of a drive, a drive never fragment might be slow, but will work as good as a defragmented one. DEFRAGMENTATION therefore will not solve this problem.
Good luck, Kees
ex2bot
Registered Bot
This thread is more about a corrupt drive format than defragging, but there's some misconception here. OS X does defrag automatically, but only to files less than 20 MB in size. There are plenty files on modern hard drives bigger than that.
iDefrag, which Dr_Fletch owns, is currently the BEST defrag util for OS X (AFAIK) because it optimizes the data, clustering more important data first on the disk. (I'm sure you can Google for a better explanation.)
iDefrag is not going to work wonders, but it can increase speed and efficiency when used occasionally. It's "only" $30. If that seems like a relatively small amount of money to you for a piece of software, it may be a worthwhile purchase.
But to say iDefrag is useless is inaccurate.
** And, again, I know Dr_Fletch's drive is corrupt and can't be fixed by defragmentaion. **
Doug
iDefrag, which Dr_Fletch owns, is currently the BEST defrag util for OS X (AFAIK) because it optimizes the data, clustering more important data first on the disk. (I'm sure you can Google for a better explanation.)
iDefrag is not going to work wonders, but it can increase speed and efficiency when used occasionally. It's "only" $30. If that seems like a relatively small amount of money to you for a piece of software, it may be a worthwhile purchase.
But to say iDefrag is useless is inaccurate.
** And, again, I know Dr_Fletch's drive is corrupt and can't be fixed by defragmentaion. **
Doug
Natobasso
Tech-Bot 5000
Apple says defragmentation is not necessary:
http://docs.info.apple.com/article.html?artnum=25668
http://docs.info.apple.com/article.html?artnum=25668
Mikuro
Crotchety UI Nitpicker
Defragmentation is generally not necessary, but sometimes it is.
OS X gets a little too much credit for it's "auto-defragmenting", which is very limited. Compared to Windows, yes, it's great. That doesn't make it perfect. It used to be a huge issue for me, really crippling my performance. These days it's not a problem (the last time I defragmented was over a year ago), because I now take preventive measures, like keeping larges files (like video) off of my startup partition.
There are many cases when defragmenting is called for — this just isn't one of them.
I still advocate the backup-erase-restore method, though. I've had bad experiences with iDefrag. Whatever you do, be sure to make backups first.
OS X gets a little too much credit for it's "auto-defragmenting", which is very limited. Compared to Windows, yes, it's great. That doesn't make it perfect. It used to be a huge issue for me, really crippling my performance. These days it's not a problem (the last time I defragmented was over a year ago), because I now take preventive measures, like keeping larges files (like video) off of my startup partition.
There are many cases when defragmenting is called for — this just isn't one of them.
I still advocate the backup-erase-restore method, though. I've had bad experiences with iDefrag. Whatever you do, be sure to make backups first.