2012 — 14 July: Saturday
I don't understand why my water softener feels the need to beep1 quite so irritatingly, quite so early in the morning, when all it's done is flush itself with brine to regenerate its resin filter. Like a child in the midst of potty training, it seems to think it must now be congratulated. Though its strategy of immediately nagging me for another dose of salt2 could have been better thought out.
Looking at the weather forecast, I feel myself wondering if I should now start building an ark. After all, I have...
... Robert Crumb's illustrated instruction manual. I wonder if I can get Cypress wood in B&Q, on a Saturday morning?
When a security firm...
... knows, several years ahead of time, of the need to hire some extra staff during that minor local sporting event, the Olympics, how can its boss seriously claim to have been unaware of the supply problems until "eight or nine" days ago? He must be on such a large performance bonus he simply got distracted, I suppose. Or perhaps underlings are reluctant to stuff his orifice with bad news? Of course, if "Private Eye" can be believed, this particular security firm has not been exactly a shining story of unblemished success over the years. (Link.)
Speaking of bad news...
... I'm fully aware of the fact that every hard drive fails, sooner or later. No exceptions.
I've just been pointed to a fascinating item introducing me to the world of TLER. (Not to mention PEBKAC.) As it happens, my little NAS system runs two pairs of 1TB drives in whichever RAID number (I always forget) means "simple mirrors". ("1", I suspect.) I therefore have 2TB capacity (not 4TB) but I also automatically have two copies of everything without any effort on my part.
Two of my chums use (or, in one case, used to use) RAID 5 (the one in which the capacity of one of the drives is given over to parity data that is dispersed among all the drives). With a four-drive RAID 5 array3 this 'costs' only 20% of the total data capacity, and theoretically allows for a complete drive failure without any data loss. It also allows for theoretically faster data access, both reading and writing, because of the parallelism (is there such a word?) across the four drives' controllers. All good stuff.
However, RAID 5 can cause simply horrid data recovery / rebuild problems in some error situations. Indeed, one chum found himself in such a world of pain a while back that he's now taken the pledge (exactly as I did with Windows "simple" disk mirroring) and won't ever go near RAID 5 again. It was on his sage advice that I opted for RAID 1.
This is the clearest explanation I've yet read of the way grief can ensue:
- Array starts off operating as normal, but drive 3 has a bad sector that cropped up a few months back. This has gone unnoticed because the bad sector was part of a rarely accessed file.
- During operation, drive 1 encounters a new bad sector. Since drive 1 is a consumer drive it goes into a retry loop, repeatedly attempting to read and correct the bad sector.
- The RAID controller exceeds its timeout threshold waiting on drive 1 and marks it offline. Array is now in degraded status with drive 1 marked as failed.
- User replaces drive 1. RAID controller initiates rebuild using parity data from the other drives. During rebuild, RAID controller encounters the bad sector on drive 3. Since drive 3 is a consumer drive it goes into a retry loop, repeatedly attempting to read and correct the bad sector.
- The RAID controller exceeds its timeout threshold waiting on drive 3 and marks it offline. Rebuild fails.
I'm not completely sure about that "gone unnoticed" in Step #1 because you should — of course — be running regular backups and array scans. (And everybody does that, I'm quite sure.) You'll have to read the full article to see what happens next. With the end of "Sounds of the 60s" it's now time for breakfast, methinks. I've let my toast get cold, dammit.
Yuk! 14C, torrential rain, and a hint of thunder. Quite a summer.
I nipped out...
... to plug a few gaps in Mother Hubbard's cupboard, trying to gauge the window of least rain. I'm sure I'll dry out soon enough. It's 13:42 and I'm hungry.
What better way to spend a cool, grey summer afternoon than working through the chaos of my MP3 file collection as I sort and sift it, in batches, through the paws of Media Monkey and generate a series of web pages that can then be battered into the sort of shape I prefer?
The results are now 'live' (as it were) here. Be aware: some of the files are whoppers. It's 22:19 and we're in the process of finalising arrangements for a road walk in the New Forest to enjoy tomorrow's (forecast) beautiful sunshine.