TOPIC: COMPUTER STORAGE DEVICES
Wiping of hard drives with Linux
2nd December 2013More than a decade of computer upgrades can leave obsolete kit in your hands, while legislation on electronic waste disposal might leave you wondering how to get rid of it. Thankfully, I discovered that my local council refuse site, only a few miles away, accepts such items for recycling. It saw me several times last summer disposing of obsolete and non-working gadgets that had stayed with me too long. Some were as bulky as computer monitors and printers, while others were relatively small.
Disposing of non-working, obsolete equipment is an easy choice, but it's harder when a device still works and might be useful. Computer motherboards still include PS/2, floppy and IDE ports, making decisions trickier. My Gigabyte Z87-HD3 mainboard has one PS/2 port (compared to two on older boards), limited IDE sockets and surprisingly, a floppy drive socket, unexpected for anyone who considers these technologies outdated. PC technology isn't abandoning backwards compatibility yet, as this mainboard supports an Intel Core i5-4670K CPU and 24 GB of RAM.
Despite the IDE port, I wasn't tempted to use my leftover 10 GB and 20 GB hard drives that I've had for over a decade. Ten years ago, that capacity would have been respectable if not for our growing need for data storage due to photography, video and music. Beyond size limitations, these drives' speed can't compare with today's standards, which became obvious when I replaced a similarly aged Samsung 160 HD with a Samsung SSD.
This line of thought led me to recycle the drives, so I considered wiping them. Linux offers a good tool for this: the dd command. It can overwrite disk data to make information virtually irretrievable. Linux also has several dummy devices that supply junk data for overwriting. These work like /dev/null, which suppresses command output. The first is /dev/zero, which supplies octal zeros, which I used. For those wanting more randomness in overwriting, there's also /dev/random and /dev/urandom.
To overwrite data on a disk with zeroes while having feedback on progress, the following command achieves the required result:
sudo dd if=/dev/zero | pv | sudo dd of=/dev/sdd bs=16M
The operation needs root privileges. The if parameter of dd specifies the input data, which is sent to pv that displays a progress bar not provided by dd alone. The output then goes to another dd command with the target disk specified by the of parameter. The bs parameter in the second dd command sets the block size for writing. Note that pv isn't installed by default. On Debian, Ubuntu or Linux Mint systems, install it with this command:
sudo apt-get install pv
The pv sandwich is also invaluable when using dd to copy partitions between different physical or virtual disks. Without it, you might wonder what's happening during silent operations, which is particularly concerning when retrying failed operations that take a long time to complete.
Pondering storage options
1st June 2011The combination of curiosity and a little spare time had me browsing online computing technology stores recently. A spot of CD and DVD burning brought on by a flurry of Linux distribution testing reminded me of the possibility. Because I have built up a sizeable library of digital photos, ensuring that I have backups of them is something that needs doing. While a 2 GB Samsung external hard drive is brought to life every now and again for that purpose, the prospect of using Blu-ray discs has appealed to me. After all, capacities of 25 GB for single-layer discs and 50 GB for dual-layer ones sound not inappropriate for my purposes. However, they aren't a cheap option at the time of writing, with each disc costing in the region of £3-4 at one place where I was looking. The cost of BD writers themselves seems not to be so bad though, with a few in the £60-100 bracket; any lower than this and you could end up with a combo drive that reads Blu-ray discs and writes to DVD's and CD's, so a modicum of concentration is needed. As attractive as the idea might be, the cost of BD media means that I'll wait a little while before deciding to take the plunge. The price premium at the moment is a reminder of the way that things used to be when CD and DVD writers first came on the market. It is very telling when discs come packaged in jewel cases, something that you won't see too often with CD's or DVD's.
Another piece of storage excitement that hasn't escaped me is the advent of SSD hard drives. With no moving parts like in conventional hard drives, they bring a speed boost. Concerns about their lifetimes and the numbers of read/write events per drive would stall me when it comes to storing personal data on them but using them for the likes of operating system files sounds attractive, especially with my partiality to Linux perhaps not hammering drives so much. As with any new technology, there is a price premium, even though a drive big enough for hosting an operating system can be acquired for less than £100. As with many of my hardware purchase brainwaves, there's no rush, but this is an option that I'll keep at the back of my mind.
Another appealing notion is the idea of getting a NAS so that files can be shared between a few computers. While I have seen prices starting at just above £70 for single disk enclosures, these generally are a more expensive option than external drives, and that's before you consider the cost of any hard drives. Nevertheless, the advantages of a unit containing more than a single hard drive while operating as a print server for any compatible printer, too. When you get to 4 or 5 hard drive trays, then the cost has mounted, but that could be when they pay their way too. What reminded me of these was a bookazine on home networking that I recently found at a branch of WHSmith's and their attractions are subject to the networking side of things being made to work without a drama. Once that's out of the way, then their usefulness really does appeal.
Mulling over all these brainwaves is one thing, but it doesn't mean that the purse strings will become too loose in this age of economic constraint. In fact, pondering them may serve to staunch any impulse purchases. Sometimes, a spot of virtual shopping serves to control things rather than losing the run of oneself.
A case of double vision?
4th November 2009One of the early signs that I noticed after upgrading my main PC to Ubuntu 9.10 was a warning regarding the health of one of my hard disks. While others have reported that this can be triggered by the least bit of roughness in a SMART profile, that's not how it was for me. The PATA disk that has hosted my Ubuntu installation since the move away from Windows had a few bad sectors but no adverse warning. It was a 320 GB Western Digital SATA drive that was raising alarm bells with its 200 bad sectors.
The conveyor of this news was Palimpsest (not sure how it got that name even when I read the Wikipedia entry) and that is part of the subject of this post. Some have been irritated by its disk health warnings, yet it's easy to make them go away by turning off Disk Notifications in the dialogue that going to System > Preferences > Startup Applications will bring up for you. To fire up Palimpsest itself, there's always the command line, but you'll find it at System > Administration > Disk Utility too.
My complaint about it is that I see the same hard drive listed in there more than once, and it takes some finding to separate the real entries from the "bogus" ones. Whether this is because Ubuntu has seen my SATA drives with SIL RAID mappings (for the record, I have no array set up) or not is an open question, but it's one that needs continued investigation and I already have had a go with the dmraid command.
Even GParted shows both the original /dev/sd* type addressing and the /dev/mapper/sil_* equivalent, with the latter being the one with which you need to work (Ubuntu now lives on a partition on one of the SATA drives, which is how I noticed this). All in all, it looks less than tidy, so additional interrogation is in order, especially when I have no recollection of 9.04 doing anything of the sort.
From laptop limbo to a new desktop: A weekend restoration of computing order
12th July 2009This weekend, I finally put my home computing displacement behind me. My laptop had become my main PC, with a combination of external hard drives and an Octigen external hard drive enclosure keeping me motoring in laptop limbo. Having had no joy in the realm of PC building, I decided to go down the partially built route and order a bare-bones system from Novatech. That gave me a Foxconn case and motherboard loaded up with an AMD 7850 dual-core CPU and 2 GB of RAM. With the motherboard offering onboard sound and video capability, all that was needed was to add drives. I added no floppy drive but instead installed a SATA DVD Writer (not sure that it was a successful purchase, though, but that can be resolved at my leisure) and the hard drives from the old behemoth that had been serving me until its demise. A session of work on the kitchen table and some toing and froing ensued as I inched my way towards a working system.
Once I had set all the expected hard disks into place, Ubuntu was capable of being summoned to life, with the only impediment being an insistence of scanning the 1 TB Western Digital and getting stuck along the way. Not having the patience, I skipped this at start up and later unmounted the drive to let fsck to do its thing while I got on with other tasks; the hold up had been the presence of VirtualBox disk images on the drive. Speaking of VirtualBox, I needed to scale back the capabilities of Compiz, so things would work as they should. Otherwise, it was a matter of updating various directories with files that had appeared on external drives without making it into their usual storage areas. Windows would never have been so tolerant and, as if to prove the point, I needed to repair an XP installation in one of my virtual machines.
In the instructions that came with the new box, Novatech stated that time was a vital ingredient for a build, and they weren't wrong. While the delivery arrived at 09:30, I later got a shock when I saw the time to be 15:15! However, it was time well spent when I noticed the speed increase on putting ImageMagick through its paces with a Perl script. In time, I might get brave and be tempted to add more memory to get up to 4 GB; the motherboard may only have two slots, but that's not such a problem with my planning on sticking with 32-bit Linux for a while to come. My brief brush with its 64-bit counterpart revealed some roughness that warded me off for a little while longer. For now, I'll leave well alone and allow things to settle down again. Lessons for the future remain, over which I may even mull in another post...