Made a mess with my swap partitions
Hi all,
i initially wanted to increase the size of my swap partition by doing: dd if=/dev/zero of=/swapfile1 bs=1024 count=xxxxx by mistake i've allocated too much of swap space (and got the message that there was no free space left on the device). then without executing {mkswap /swapfile1 and swapon /swapfile1} i've deleted that same swap partition (/swapfile1) by swapoff /swapfile1 rm /swapfile1 as a result i've been left with my main partition /dev/hda5 FULL Filesystem 1K-blocks Used Available Use% Mounted on /dev/hda5 73142560 73076172 0 100% / i.e my swap mess has partitioned the rest of my hda5 device. Is there a way of freeing that space without damaging the files that are already on hda5 ? I've rebooted the computer but the memory that has been allocated has not been freed at the reboot - all my files previously on /dev/hda5 are still fine ... any idea thanks. |
What distribution / version of linux are you running?
Try booting from a rescue or live CD and run fsck on hda5. BTW you were trying to create a swap file not a partition. You only filled the partition up, you didn't change the partitioning of hda5. Were you logged in as root when you messed everything up? Was swapfile1 actually deleted? |
Quote:
Hi, I'm running a RH8 distro Linux 2.4.18-14 i686 i686 i386 GNU/Linux. Yes you are right i was trying to create a swap file not a partition. I was logged as root unfortunately. The only swap partition that remains is the old one, the new one (i.e the file) that i've created has been deleted by a rm command (i did however executed swapoff /swapfile1 before that) the cat on /proc/swaps gives me [root] cat /proc/swaps Filename Type Size Used Priority /dev/hda6 partition 1044184 0 -1 [root] mount /dev/hda5 on / type ext3 (rw) /dev/hda3 on /boot type ext3 (rw) i will try to check /dev/hda5 from the boot floppy using fsck any additional tips are very welcome |
I have one question can i boot with GRUB in a single user mode and then run fsck on my /dev/hda5 ?
thanks. i.e |
If you have the RH8 install cd you should be able to boot into the rescue mode and run fsck.
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Hi thanks,
i've managed to run fsck from GRUB in a single user mode this is what i did at the prompt after booting with GRUB using " single" umount /dev/hda5 fsck -t ext3 /dev/hda5 and got ... fsck 1.27 (8-Mar-2002) e2fsck 1.27 (8-Mar-2002) /: clean, 229301/9289728 files, 18562727/18577156 blocks my /dev/hda5 is still 100% full ... any idea would be most welcome ! |
Actually i've just found swap files that i've created !
[roo]]# ll -h /swapfile* -rw-r--r-- 1 root root 2.0G Nov 10 12:26 /swapfile -rw-r--r-- 1 root root 33G Nov 30 19:04 /swapfile1 -rw-r--r-- 1 root root 2.0G Nov 16 21:11 /swapfile2 how should i delete them should i first do: [root]swapoff /swapfile then use rm after swapoff ? i.e [root] rm /swapfile ? thanks again. MORE ... if i do [root]cat /proc/swaps Filename Type Size Used Priority /dev/hda6 partition 1044184 0 -1 they do not figure as swap files should i just delete them using rm ? |
Since they are not being used as swap just delete them using rm.
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OK it worked thanks michaelk !
[root]df Filesystem 1K-blocks Used Available Use% Mounted on /dev/hda5 73142560 34247172 35179960 50% / |
To create a 20mb swap file example:
dd if=/dev/zero of=/usr/local/newswap bs=1000000 count=20 chmod 600 /usr/local/newswap (set permissions) mkswap /usr/loca/newswap (create filesystem) swapon /usr/local/newswap (to activate it) /usr/local/swapfile swap swap defaults 0 0 ( add to /etc/fstab to activate it at boot) Change the location as desired. |
thanks - how about creating a swap file with 6GB (i know that this is really huge) for example in my Linux book it is written that swap files can only go up to 2GB ? Thus i will have to create three swap files each with 2GB size ? Do you know if three separate swap files are recognized as one when running a hypothetical program that uses that much memory ?
cheers Vania |
I recommend that swapping should be done to partitions, or even dedicated drives, and that those should be scattered across the various I/O channels and devices. If you have advanced bus-architectures such as SCSI or FireWire, which are capable of physically-simultaneous I/O operations, those are great to use for swap. You certainly want to pay attention to all opportunities for parallelism: for example, on a single IDE-chain the master and the slave cannot (afaik) be simultaneously active, but perhaps you have two such chains on your motherboard (or a bus-installed driver card, of course).
The rule of thumb is that your swap space should be twice the size of your RAM. |
The 2x rule of thumb is IMO outdated. It depends on what applications you run and how you use the computer. Someone that only uses a email, web browsing and basic office stuff with >512mb of memory might never use swap. Multiple swaps are recognized as one. With a 2.4 kernel you can have 32 partitions ( or files) * 2GB ea. Swap files are slower then swap partitions but can be used in a flash if additional space is required.
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