RAID1 1.5TB formats with 133mb "used" space no paritions

R

Rad777

Limp Gawd
Joined
Jun 7, 2004
Messages
205
I've purchased four WD EARS 4k drives 1.5TB each, two of them were DOA seek/click error. The other two were ok... HOWEVER.... after formating there appears to be 133mb of "USED" space. This appears in both linux/windows. The drive shows 100% empty, but there it is 133mb "USED" space and an available 1.36TB; also didn't see any extra partitions.

I formated in Windows 7 and never do 'quick format' on new drives (for sector scanning).

I initially set these up in RAID 1 with ati/amd 750(sb), then went into windows for formating.

Anyone have a clue why there would be so much "used" space yet still display 100%? Is the ~133mb bad sectors? Any help would be appreciateed. Thanks
 
So what is the problem? You know every filesystem reserves space for internal usage, and now you got 4KiB sectors these add up more quickly.

What do you mean with never do a quick format? Its not like that would kill a HDD.
You setup RAID, are you sure your RAID controllers properly supports 4KiB sectors? Else you may run into problems later. By the way, RAID1 is pretty useless to consumers. If you want a backup, forget about RAID and make the backup yourself. RAID1 is worth much less than a real backup, because RAID1 cannot protect against all dangers a backup protects against.
 
How is RAID1 not for consumers? RAID1 offers higher read speed and seamless redundancy. Relying solely on backups would results in two things, an external hard drive or lots of DVDs; which one take time to perform and don't protect everything and you get no increased read speed.

I mentioned quick format because most people do quick format instead of getting the entire hard drive scanned for bad sectors initially so the HD skips those instead of writing an ISO only to find it is useless later.

Now back to my initial question: the used space.... Maybe I have been brainless the last so many years, but why would a single parition non boot drive require reserved space in upward amounts of 100mb+? I've never seen that before.
 
RAID1 is not for consumers because its protection is limited and the major feature of RAID1 ("availability") is not relevant to home users. Servers can't afford to be down for even a minute, but for home users this is less of a problem, and the bigger issue is preventing loss of data. A backup does a much better job at that, because it is unaffected by filesystem corruption (you have 2), accidental deletion and virusses that corrupt files, RAID layer that fails, etc.

The increased read speed is only true for intelligent RAID engines, most RAID1 engines just read from a single disk, others try to increase speed but fail at doing so. Only in some cases will you get true additional speed from a RAID1.
 
IMO Raid 1 is for consumers. Its simple you have a disk fail and your system still works and you dont have to rely on backups.

WHAT IS WRONG WITH RAID1 AND USING BACKUPS???

Nothing heh. Raid1 rocks and I use it everywhere possible.
 
I also agree RAID1 *is* for consumers. Simply because you don't see RAID1 very often in corporate server environments. RAID1 is a cheap and simple way of providing hard drive redundancy for Joe The Consumer. I've been in I.T. for 15 years (server admin and now network engineer) and I've never heard of a server running RAID1 because of limited multi-threaded performance when compared to a multiple disk array, among other reasons. All the servers I've ever dealt with over the years were either running external SAN arrays, or local RAID5 or 6 arrays, and I've seen RAID 1+0 on some Unix boxes. Granted the companies I've worked for had the budget for higher end servers. But RAID1 is definitely not the first choice for corporate environments unless you're dealing with a limited budget.
 
RAID1 is used by consumers as easy backup - instead, its not a backup:
  • Filesystem damage/corruption would affect both disks in the RAID
  • Virusses or accidental deletion that causes dataloss
  • Both drives still rely on one shared system: the RAID engine often a driver; if this fails (and it does especially on windows) you may also lose access to data either temporarily (broken array) or permanently (rare with RAID1)
  • a RAID array pretty much implies its on the same system, so vulnerable to any damage from a power supply issue, fire or other disasters that may be rare but can be avoided if you keep a backup at another physical location

In short, a backup protects you against many more dangers than RAID alone ever can. Since RAID1 means you lose 50% capacity to redundancy, its not superior to a backup at all. A backup costs you the same space or less (as you backup files not sectors) while offering more protection. That means its best used by home users.

What a backup doesn't provide is availability; keeping data available at all times. A RAID1 with a failed disk will continue to function without downtime for the (server) administrator. Rebuilding the RAID1 is usually online anyway, meaning no downtime at all is necessary when restoring from a disk failure. This means its the prefered choice for servers, who have backups anyway but backups alone is not enough; the server has to continue running.

So RAID1 is for servers, not for home users. While it may be a ''quick and dirty" way to backup files, its not a true backup and other setups like an incremental backup that synchronizes every day or week are superior since they lend more protection at the same required disk capacity overhead.
 
You must log in or register to reply here.
Back
Top