Quickie: How do I check my data is safe on dropped ext HD?

Lave II

G&T I call on your awesome knowladge once again.

I back up all my PhD work to a 250Gb Lacie external hard drive, which I've just dropped a good 5ft onto a wooden floor. It clattered around making an awful racket - but thankfully was turn off at the time.

It seems fine, but there is 10Gb of text, data, and so on which is pretty essential - and rather than check each individual file is there a way to check it's all ok?

I've easiest access to Mac and Unix machines, but if really essential I could borrow a friends windows laptop. Though It's partitioned into Mac Standard....

Do you think my HD drive is on borrowed time now? Should I transfer everything before it breaks?

taliosfalcon

HDD's can usually take some pretty hard hits and be fine as long as they're off at the time. Really if all the files you've checked are fine its very unlikely that any were damaged, usually with a fall its either all or nothing. That being said if you have essential data on it, it should be backed up somewhere else anyway, because HDD's can and do fail, sometimes for no reason.

Lave II

Thanks man.

I've the "live copy" on my iBook, and 3 backups on the external (I have Silverkeeper that keeps the last 3 backups seperate). And thats it.

It's just my trust in it has faltered a little now. The problem is that my essential data is thousands of small files. Text files, scripts, ps pdfs, astronomy data files. So I can't check them all individually. But as it was off , the likelyhood getting bad sectors is pretty low right?

I'm skint at the moment, but maybe I should sell a few games and get a new external. This ones pretty full anyhow.

Rook

chkdsk is the windows one, I'm sure there's a mac alternative.

Lave II

Cheers rook,

It seems the unix version is fsck but I'm put off trying as:

Fsck can also be run manually by the system administrator if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.

A journaling file system is designed such that tools such as fsck do not need to be run as often. The UFS2 Filesystem in FreeBSD has background fsck, so it is usually not necessary to wait for fsck to finish before accessing the disk.

Now this is a mounted file system, and journaled. Hmmm. I'll have a dig about.

MKR

Get a file diff program and make a diff of each set of files, and see if there are any differences.

Daedalus

Lave II wrote: »

Cheers rook,

It seems the unix version is fsck but I'm put off trying as:

Fsck can also be run manually by the system administrator if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.

A journaling file system is designed such that tools such as fsck do not need to be run as often. The UFS2 Filesystem in FreeBSD has background fsck, so it is usually not necessary to wait for fsck to finish before accessing the disk.

Now this is a mounted file system, and journaled. Hmmm. I'll have a dig about.

Unmount it first, I guess. Dunno what the command is on a mac, but it should be something like umount (path to where the drive is mounted).

Lave II

Daedalus wrote: »

Lave II wrote: »

Cheers rook,

It seems the unix version is fsck but I'm put off trying as:

Fsck can also be run manually by the system administrator if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.

A journaling file system is designed such that tools such as fsck do not need to be run as often. The UFS2 Filesystem in FreeBSD has background fsck, so it is usually not necessary to wait for fsck to finish before accessing the disk.

Now this is a mounted file system, and journaled. Hmmm. I'll have a dig about.

Unmount it first, I guess. Dunno what the command is on a mac, but it should be something like umount (path to where the drive is mounted).

But, but, surely then I couldn't see the drive at all. Thats what I've always taken unmounting to mean....

EDIT: Oh, I'll look into diff'ing but I've a good 10,000 odd files I think, and thought diff only worked on text files.

Really appreciate the suggestions. Cheers!

Daedalus

Lave II wrote: »

Daedalus wrote: »

Lave II wrote: »

Cheers rook,

It seems the unix version is fsck but I'm put off trying as:

Fsck can also be run manually by the system administrator if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.

A journaling file system is designed such that tools such as fsck do not need to be run as often. The UFS2 Filesystem in FreeBSD has background fsck, so it is usually not necessary to wait for fsck to finish before accessing the disk.

Now this is a mounted file system, and journaled. Hmmm. I'll have a dig about.

Unmount it first, I guess. Dunno what the command is on a mac, but it should be something like umount (path to where the drive is mounted).

But, but, surely then I couldn't see the drive at all. Thats what I've always taken unmounting to mean....

EDIT: Oh, I'll look into diff'ing but I've a good 10,000 odd files I think, and thought diff only worked on text files.

Really appreciate the suggestions. Cheers!

If you unmount the drive, you can't read the contents in a file browser or what have you, which makes it safe to fsck, since fsck works on a device level.

At least, this is all Linux experience talking, so I've no idea if it works on a mac. In fact, I'll bet Apple has some kind of gui-based thing to do what I'm talking about here.

MKR

Lave II wrote: »

Daedalus wrote: »

Lave II wrote: »

Cheers rook,

It seems the unix version is fsck but I'm put off trying as:

Fsck can also be run manually by the system administrator if there is believed to be a problem with the file system. However, running fsck on a mounted file system can potentially cause severe data corruption/loss.

A journaling file system is designed such that tools such as fsck do not need to be run as often. The UFS2 Filesystem in FreeBSD has background fsck, so it is usually not necessary to wait for fsck to finish before accessing the disk.

Now this is a mounted file system, and journaled. Hmmm. I'll have a dig about.

Unmount it first, I guess. Dunno what the command is on a mac, but it should be something like umount (path to where the drive is mounted).

But, but, surely then I couldn't see the drive at all. Thats what I've always taken unmounting to mean....

EDIT: Oh, I'll look into diff'ing but I've a good 10,000 odd files I think, and thought diff only worked on text files.

Really appreciate the suggestions. Cheers!

Diff should work on binary files too.