4 ms·
I didn't expect Brendan Gregg talking about anything but Cloud anymore, but here here is! I appreciate his curiosity-chasing storytelling. I wonder how to "rea
by flakiness 5y ago
I didn't expect Brendan Gregg talking about anything but Cloud anymore, but here here is! I appreciate his curiosity-chasing storytelling.
I wonder how to "read over 99.9999% of disk sectors successfully". Is there any handy script to do this without harm? Then I can try these tools locally on my Ubuntu laptop to see the numbers.
- aidenn0 5y agoddrescue is pretty good; it strides over the disk reading in big chunks, and writes out a map file of which chunks failed. Then it goes sector-by-sector over the failed chunks to fill-in the holes.
- flakiness 5y agoIt seems a scary option to try casually :-/ > Never try to rescue a r/w mounted partition. The resulting copy may be useless. It is best that the device or partition to be rescued is not mounted at all, not even read-only. https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html https://www.gnu.org/software/ddrescue/manual/ddrescue_manual...
- aidenn0 5y agoYes, if you make a raw copy of a disk you are also concurrently writing to, you won't have a snapshot of the disk. Nothing surprising there, right? [edit] Also that section isn't talking about damaging the original disk, but rather ending up with a useless copy. If you have a malfunctioning device then using it in any way may cause further malfunctions, but in general running something like ddrescue isn't going to destroy something that wasn't already about to self-destruct anyways.