hard drive replacement questions
Henry Yen
blinux-mail at AegisInfoSys.com
Fri Sep 28 08:59:08 UTC 2012
Sorry I've been preoccupied, so here are some additional thoughts on this
thread.
1. Badblocks only finding 13 bad blocks is a good thing. Hopefully that
means you might have just a single bad spot on the disk, and there
isn't a huge amount of damage. On the other hand, those middle-age
IDE drives probably didn't do as good a job at remapping bad sectors,
and they had fewer of them, so there may still be damage that either
badblocks can't see, or all of the remapping spare sectors are all
used up, which would mean many bad sectors had already been detected,
and the remapping might not have been completely successful on some
of them.
2. A command everyone should know is: dmesg
That command prints out all of your boot-up messages. The identity
of drives will either be in lines beginning with "hda:" "hdb:" (etc.)
for IDE drives, and lines containing "Vendor:" and/or "Model:" for
scsi/sata drives.
3. The "fsck -vcck" command (as well as use of "badblocks", by the way),
unfortunately puts further stress on the disk. "fsck" is not 100%
reliable to try and fix things in the face of hardware errors.
It was designed primarily to try and recover from logical/filesystem
inconsistencies if the system crashed or power-failed.
4. eBay and MicroCenter are two sources I've used with good success to buy
almost any computer/electronics components. A 60GB IDE laptop drive
runs about $40, and a 120GB drive runs about $60. You might consider
going to a Solid-State drive ("SSD") instead (not recommended if your
Linux kernel is more than about 18 months old), as modern SSD's run at
about half the power consumption of spinning disks while providing
about twice the performance. SSD's in the 40GB-ish range are at a sweet spot
now-a-days with pricing for the SSD in an IDE laptop kit to be around $50.
5. Make sure you get a replacement drive that is at least as large as your
old drive. You should be able to clone your old drive completely to your
new drive using ddrescue or dd-rescue; these cousin commands are based on
"dd", but continue on in the face of errors, and use strategies like
copying from the end towards the beginning, and in chunks, to absolutely
maximize the amount of data copied. After doing that, your new drive
will be exactly the same as your old drive (including the logical damage,
which will at least no be afflicted with physical error problems), and
you should be able to even boot both systems just as before.
You can also fsck the new drive, as it won't get confused by
hardware failures any more.
6. Actually copying the drive could be tricky for you, depending on
what hardware you have available. A USB drive converter is the least
common denominator, but it's deathly slow. A separate "work space"
system on your local network would be better.
7. For future reference, there are various partition cloning/backup
systems for Linux that support Linux and Windows partitions, and are
very fast (mostly because only blocks that are actually being used are
copies, and blocks in the free list are not).
--
Henry Yen Aegis Information Systems, Inc.
Senior Systems Programmer Hicksville, New York
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