Secondary HD problem

[werdigo49]

Glad to see the Kubuntu Forums back up! I posted this over on Ubuntu and got
no replies.

After a month of being away, I booted my Kubuntu 10.10 system and it could not
read or write to my primary backup SATA disk, "disk-1." Dolphin shows its partitions
in the left "Places" pane, and selecting my 166G Reiserfs main partition shows its
folders and files. I could get down one more level in the folders, but then just a
blank pane. A simple text file in a top-level folder opened OK with Kwrite, but an
.ods spreadsheet was reported as corrupted.

I booted my old Hardy system (Klikit), and it read and wrote to that partition
perfectly. (I rsync'd it to another data disk that both Klikit and Kubuntu
mounted and handled fine, so I don't think I'll suffer any data loss.) It opened
the .ods spreadsheet quickly and perfectly.

In Kubuntu, Gparted doesn't even see disk-1, and the blue "Kubuntu" startup
screen flashes a message that "An error occurred mounting /media/disk-1. Press S
to skip or M for manual..." and then the bootup proceeds. MountManager shows
disk-1, but can't seem to actually mount it.

Any suggestions? I figured the disk was failing, but it works perfectly under
Klikit (based on Kubuntu 8.04).

[dibl]

Re: Secondary HD problem

"An error occurred mounting /media/disk-1. Press S
to skip or M for manual..."

I think that's your clue that the OS wants you to fsck that filesystem. First, you must unmount the filesystem (use "umount") or better yet boot a Parted Magic Live CD and make it easy on yourself.

sudo e2fsck -vp /dev/sdxy

is the console command, where x = your disk and y = the partition in question.

[werdigo49]

Re: Secondary HD problem

Thanks, dibl! BTW, I just booted up a 10.04 CD and it read the data files on that disk partition perfectly.

Pardon the newbie question, but will fsck modify the data files on that disk partition? Meerkat seems to think they're corrupted, but when I open them using other OS's (including Lucid Lynx) they seem to be fine. I don't want to do anything that would damage them.

Oops, another issue: That's a reiserfs partition. I followed the 6-part example on the reiserfsck man page, and got this:

***********************
The problem has occurred looks like a hardware problem. If you have
bad blocks, we advise you to get a new hard drive, because once you
get one bad block that the disk drive internals cannot hide from
your sight,the chances of getting more are generally said to become
much higher (precise statistics are unknown to us), and this disk
drive is probably not expensive enough for you to you to risk your
time and data on it. If you don't want to follow that follow that
advice then if you have just a few bad blocks, try writing to the
bad blocks and see if the drive remaps the bad blocks (that means
it takes a block it has in reserve and allocates it for use for
of that block number). If it cannot remap the block, use badblock
option (-B) with reiserfs utils to handle this block correctly.

bread: Cannot read the block (2): (Input/output error).

Aborted
********************

I haven't tried the --rebuild-tree option yet.

[dibl]

Re: Secondary HD problem

reiserfs was once a very good filesystem, but it has not been seriously maintained for years and years .....

I'll let you do the research. ext4 would be a far better choice, at this time.

[werdigo49]

Re: Secondary HD problem

reiserfs was once a very good filesystem, but it has not been seriously maintained for years and years .....

I'll let you do the research. ext4 would be a far better choice, at this time.

Thanks. I'm still puzzled why Lucid and two different Hardy systems allow sda1 to be mounted, folders to be examined, and files to be opened, while Meerkat reports the same files (when I can even get to them) to be corrupted.

At the moment I'm running a Hardy system (RevLinuxOS), and have the problem partition (sda1 on the Meerkat setup) and another disk's partition (to which I'd rsync'd the questionable one) open, side by side. Comparison shows some folders are missing from sda1. I guess it really is time to pick up a new disk.

Thanks for the tip re reiserfs and ext4. I haven't kept up with those changes, vaguely recalling that, a few years ago, reiser seemed to be the fs of choice. I'll compare ext3, ext4, and reiser before formatting that new disk.

[wizard10000]

Re: Secondary HD problem

Thanks for the tip re reiserfs and ext4. I haven't kept up with those changes, vaguely recalling that, a few years ago, reiser seemed to be the fs of choice. I'll compare ext3, ext4, and reiser before formatting that new disk.

I liked ReiserFS too but quit using it when Hans Reiser went to prison as I'd prefer not to trust my data to a filesystem whose future is uncertain. Besides, ext4 solved (so far) all my earlier complaints about ext filesystems.

[dibl]

Re: Secondary HD problem

I'm still puzzled why Lucid and two different Hardy systems allow sda1 to be mounted, folders to be examined, and files to be opened, while Meerkat reports the same files (when I can even get to them) to be corrupted.

I'm not aware of a specific issue with Meerkat and reiserfs -- google might turn up something on that. But, referring to the rapid obsolescence of reiserfs, it is to be expected that a newer OS will have more trouble with it than an older OS. That is the natural consequence of unsupported software -- sooner, or later, it doesn't work right in a newly-released operating system.

[oshunluvr]

Re: Secondary HD problem

Just to throw my two cents in: I've using reiserfs for about five years - ever since a system crash on an ext3 partition caused total loss of a system. I have not lost a file since switching to reiserfs and the speed for a system drive is better than ext3/4. Ext4 was/is planned to be a temporary replacement for Ext3 so that and the problems with ext4 lead me to believe I was better off without it (I use RAID and ext4 still has serious issues with software RAID).

Currently, all my systems use reiserfs for system and home partitions, I use XFS on my server for backup images and media file storage but I am converting it to btrfs.

Supposedly, ext3 is the worst at drive space usage but uses less CPU time and mounts faster than reiserfs and XFS. JFS, also commonly used for large file storage is slower than XFS but uses less CPU time. ext4 is better performing than most the others but requires more CPU.

If you're using meerkat and aren't storing large amounts of critical data without backups - you might just want to jump into btrfs. You need a kernel newer than 2.6.32 for the best performance and mounting with the "compression" option is even faster. Natty even has a btrfs option in the Alternate install CD (not sure about meerkat). Ext4 will not be developed once btrfs is totally main stream (just IMO). Reiserfs (again IMO) was the only choice until 2010.

[dibl]

Re: Secondary HD problem

Heading the rest of the way OT ....

Perhaps the most stable Linux system I've had since I started using it in 2005 was on a JFS filesystem -- it ran two years with daily and vigorous usage. If I had read the upgrade warning on the user forum, before I clicked "Y" on a dist-upgrade in 2009, it would probably still be running today.

I also watched an operating system that was installed on a XFS partition slowly eat itself, over a six-month period. So I'm not a fan of putting the OS on XFS.

Today, my desktop and netbook installations are all on ext4 for the operating systems, and I've got a large 2-disk btrfs system that has my 450GB of data on it and seems to be very stable for some months now. Just FYI.

[oshunluvr]

Re: Secondary HD problem

Don, are you using the space_cache and compress (or compress-force) options? Test data shows great speed gains when using both options at once.

[dibl]

Re: Secondary HD problem

I just got a 2.6.37 kernel last week, and I have not yet tried the new btrfs options. Maybe a project for this weekend ...


EDIT: After a 100% backup is completed!

EDIT #2: I can enable the space_cache option with 2.6.37, and the compress option with whatever default compression is provided, but we must wait for 2.6.38 to use compress with a selected zlib or lzo compression algorithm, as it says here: https://btrfs.wiki.kernel.org/index.php/Getting_started

[oshunluvr]

Re: Secondary HD problem

Latest I read shows zilb is better anyway - at least for now

[Snowhog]

Re: Secondary HD problem

Well, from the btrfs Wiki, this would give me great pause in deciding to utilize btrfs:

Note that Btrfs does not yet have a fsck tool that can fix errors. While Btrfs is stable on a stable machine, it is currently possible to corrupt a filesystem irrecoverably if your machine crashes or loses power on disks that don't handle flush requests correctly. This will be fixed when the fsck tool is ready.

[dibl]

Re: Secondary HD problem

Note that Btrfs does not yet have a fsck tool that can fix errors. While Btrfs is stable on a stable machine, it is currently possible to corrupt a filesystem irrecoverably if your machine crashes or loses power on disks that don't handle flush requests correctly. This will be fixed when the fsck tool is ready.

Yep -- "backup early, backup often" is the word to the not-so-wise.

However, it also says

many users have been experimenting with Btrfs on their systems with good results

and I am one of those (3+ months, no errors or issues). So, we'll see what "space_cache" and "compress" do for me, and the worst possible outcome is that I might have to restore my fresh backup. No worries!

[oshunluvr]

Re: Secondary HD problem

Hmmm, btrfsck exists on my install. But it seems to be still under heavy development. I haven't needed it yet and have been using btrfs lightly for about eight months.