Berkeley CSUA MOTD:Entry 15223
Berkeley CSUA MOTD
 
WIKI | FAQ | Tech FAQ
http://csua.com/feed/
2025/05/24 [General] UID:1000 Activity:popular
5/24    

1999/1/13-15 [Computer/SW/OS/Linux, Computer/HW/Drives] UID:15223 Activity:moderate
1/26    Let's say I accidentally deleted my entire Linux partition. How do
        I restore the files, assuming that I know that the file names are gone?
        \_ mt rewind ; restore i
     \_ dd if=/dev/sd0a | more
        \_ Thanks. So how do I convert this huge content into files?
           \_ Wow!  You sure are fucked!  How'd you manage to wipe the
              partition?
           \_ afraid that's your problem, bubba. if you REALLY cared,
              you might try to write a program that is kind of a "strings"
              for disk sectors. It would look for sectors that start with
              ascii data, then write all following information, until
              it hit a '\0' somewhers. This is taking the chance that
              your disk was formatted with all sectors zero-filled.
              You also then need to deal with file fragmentation.
              By hand. You have about a month's work ahead of you,
              probably.
              Btw, if this was a traditional ufs partition, i would
              tell you to try to use one of the "alternate superblocks"
              to try to recover inode info.
     \_ If you deleted the partition (with fdisk) -- just re-create it
        in the same place; it will work.  If you deleted files -- ext2fs
        has undelete info; you can use mc or other tool.
        Of course, dd will work, too.
        \_ debugfs might help in some cases too.
2025/05/24 [General] UID:1000 Activity:popular
5/24    

You may also be interested in these entries...
2013/2/19-3/26 [Computer/SW/OS/OsX] UID:54611 Activity:nil
2/19    I program a lot by sshing to a Linux cluster.  So I'm used to using
        Xemacs to code.  This works fine from a Linux or Windows workstation,
        but sometimes I have to use a Mac.  On Mac, the meta is usually
        bound to option, but that often doesn't work over ssh for some reason.
        This makes using emacs a real pain.  Any suggestions on how to fix it?
        (Other than "use vi")
	...
2012/8/28-11/7 [Computer/HW/Memory] UID:54466 Activity:nil
8/26    Amazon medium instances (3.75GB RAM): 0.160/hour = $1382/year
        Generic standard Linux VPS (4GB RAM): $480/year
        Amazon costs more (but does offer superior scaling options).
        \_ Amazon is $670 if you buy a year's usage up front (heavy util).
           Why is heavy util less expensive than light util?
	...
2012/1/4-2/6 [Computer/HW/Drives] UID:54281 Activity:nil
1/4     I want to test how my servers behave during a disk failure and
        a RAID reconstruction so I want to simulate a hardware failure.
        How can I do this in Linux without having to physically pull
        a drive? These disks are behind a RAID card and run Linux. -ausman
        \_ According to the Linux RAID wiki, you might be able to use mdadm
           to do this with something like the following:
	...
2010/7/21-8/9 [Computer/SW/OS/FreeBSD] UID:53890 Activity:nil
7/21    Can I just use ifconfig to expand my netmask on a FreeBSD box?
        Are there any gotchas here? Linux forces me to restart my network
        to expand my netmask.
        \_ yes... and no, you don't have to restart your network on linux either
           \_ Rebooting is the Ubootntoo way!
              \_ Oooboot'n'tootin!
	...
2010/7/22-8/9 [Computer/SW/OS/FreeBSD, Computer/HW/Drives] UID:53893 Activity:nil
7/22    Playing with dd if=/dev/random of=/dev/<disk> on linux and bsd:
        2 questions, on linux when <disk>==hda it always gives me this off
        by one report i.e. Records out == records in-1 and says there is an
        error. Has anyone else seen this?  Second, when trying to repeat this
        on bsd, <disk>==rwd0 now, to my surprise, using the install disk and
        selecting (S)hell, when I try to dd a 40 gig disk it says "409 records
	...
2010/5/26-6/30 [Computer/SW/Unix/WindowManager, Computer/SW/OS/OsX] UID:53844 Activity:nil
5/26    anyone use lxde?  supposedly it is less stupid than xfce and
        less bloated than gnome.  thoughts?
        \_ lol, does anyone still use desktop linux?  Get with the times
           buy a mac.  Now.  DO IT.  Go NOW.
           \_ but we prefer herring to Kool-Aid
              \_ "you have to yell, he's hard of herring"
	...
2010/5/6-26 [Computer/SW/OS/Windows] UID:53818 Activity:low
5/5     Does anyone know how to do custom install of Ubuntu 10.04? I can't
        even boot it up to give me the menu to custom install and it
        keeps installing a bunch of crap I don't need. It's getting
        just as slow and bloated as Winblows install. Dear lord,
        I miss the old Ubuntu.
5/5=1.0 Numerology FTW.    5+5=10
	...
2010/4/22-5/10 [Computer/SW/Languages/Misc] UID:53797 Activity:nil
4/22    In Linux is there an easy way to rename the scripts in /etc/rc?.d ?
        For example I want to set all the /etc/rc?.d/S91apache to S100apache
        so that it'll run the ramdisk BEFORE going to apache.
        \_ Sure, just move them.
           \_ I mean is there a script that will rename all of them
              for me? Like: setrc apache2 0 0 1 1 1 1
	...
2011/9/14-10/25 [Computer/HW/Drives] UID:54173 Activity:nil
9/13    Thanks to Jordan, our disk server is no longer virtualized. Our long
        nightmare of poor IO performance should hopefully be over. Prepare for
        another long nightmare of poor hardware reliability!
        ...
        Just kidding! (I hope)
        In any case, this means that cooler was taken out back and shot, and
	...
2011/2/14-4/20 [Computer/SW/Unix] UID:54039 Activity:nil
2/14    You sure soda isn't running windows in disguise?  It would explain the
        uptimes.
        \_ hardly, My winbox stays up longer.
        \_ Nobody cares about uptime anymore brother, that's what web2.0 has
           taught us.  Everything is "stateless".
           \_ You;d think gamers would care more about uptime.
	...
2009/10/27-11/3 [Computer/HW/Drives] UID:53474 Activity:nil
10/27   I just read an article that Facebook had moved their database
        to all SSD to speed throughput, but now I can't find it. Has
        anyone else seen this? Any experience with doing this? -ausman
        \_ I hope you're not running mission critical data:
           http://ask.slashdot.org/story/09/10/27/1559248/Reliability-of-PC-Flash-SSDs?from=rss
        \_ Do you have any idea how much storage space is used by Facebook,
	...
2009/8/4-13 [Computer/SW/OS/Windows] UID:53239 Activity:kinda low
8/3     VMWare + Windows XP + Validation question. I need to test stuff with
        Service Pack 3 installed. I have a valid key that I own (yeah yeah I
        actually *bought* a copy, please don't flame me for supporting evil
        M$). Is it possible to register the key once, and then duplicate it
        for testing purposes?  Will Windows or Microsoft detect copies and
        disable the rest the copies?
	...
2009/7/28-8/6 [Computer/HW/Drives] UID:53216 Activity:nil
7/28    Does it make sense to defragment disks on VMWare? My 80GB disk
        on VMWare isn't really using 80GB, it just uses what it needs.
        Will defragment do anything to it?
        \_ If you want to speed up disk operation in your VM, it's best to
           defragment the disks in your VM, then defragment the disk on your
           host machine where the VM files are.
	...
2009/7/24-27 [Computer/SW/WWW/Browsers, Computer/SW/OS/OsX] UID:53191 Activity:kinda low
7/24    Firefox 3.5.1 on MacOS is a piece of crap. It crashes ALL THE TIME.
        It has crashed 3 or 4 times on me in the last hour, and not on
        the same pages either. The new Yahoo! home page also sucks ass.
        \_ os x keeps trashing my raid disk: '11 hours to rebuild. have fun
           with the kernel IO subsystem running like shit until then".
           Worthless piece of shit.
	...
2009/7/17-24 [Computer/SW/OS/OsX] UID:53156 Activity:kinda low
7/17    -rw-r--r--@
        What does the "at sign" mean? This is on Mac OS. VMWare disk file.
        \_ The file has metadata attributes
           \_ How do I add/delete attributes to files? What about
              -rw-r--r--+ <-- what is the "+" sign? Also how do you make
              tar preserve these attributes?
	...