Can hard drive partitions be corrupted

hard drivepartition

Our previous sysadmin created several partitions inside one hard drive in the fileserver, saying that it minimizes corruption:

In case one partition goes bad, it doesn't affect others.

Question: I've never seen a partition goes corrupted, so is it true?

Machine: Dell R200, 1TB hard drive with 6 partitions (that he created), Windows Server 2003

Please note that this server is just used to serve files & also store ex-staff files.

Best Answer

For the most part a 'corrupt partition' is actually referring to a corrupted filesystem. Filesystems are contained within partitions(1). So if the filesystem in one partition gets corrupted, the filesystems in different partitions on the same disk will not be. That said, the same event (abrupt power-down, others) that corrupted one filesystem can also corrupt other filesystems on the same disk.

Actually corrupting a filesystem takes some doing these days. I've seen some pretty bad NTFS pukes, but they were all related to exceptional events. A good way to cause problems is to yank the powercables out the back of a Windows server while it's doing heavy I/O. For SAN-attached storage (not your problem) sometimes if the SAN hiccups for some reason the OS can react strangely; I had a case on Server 2003 where just such a hiccup caused Windows to flag about 20GB of the partition as bad-clusters (they weren't, a chkdsk /F /R removed the bad-flag from those clusters). Abrupt power loss is probably the most common cause of such problems. Having your drive partitioned so that your heavy I/O applications are on a different partition than your OS boot environment means that when the power is yanked the chances of boot being affected are much smaller.

(1) Unless they're part of a volume management system like LVM, or Microsoft Dynamic Disks, at which point things get a bit fuzzier.

Related Solutions

Freebsd – Why does slice C or slice 2 cover the entire disk

Back in the old days we would do backups using "dd" of the entire disk. Therefore, we had the "c" slice so that we could do it all with one command.

That's why the "c" slice exists.

DD isn't perfect. If a disk is only 10% full you spend 90% of your time copying blocks that are "junk" or (for example) are used for "swap" (useless to be backed up). "dd" is a waste of time unless your disk is nearly full or if, for some reason, you need an exact, block-by-block, copy.

This was all before RAID-0 disk mirroring and volume managers did all that kind of partition copying for you.

(Someone mentioned "dump" on the "c" slice. That won't work. "dump" is a file-by-file copy [actually, inode by inode] so that won't work.)

Someone else asked "why is it c, not the first partition, or the last". The answer is "tradition". I can only guess that Ken or Dennis (or possibly Bill Joy or Kirk McKusick) had a good reason at the time. I assume they had used the first two partition labels for actual partitions. Then one day someone had the idea of the over-lapping partition for doing backups and "c" was the next partition available. Since there were only 2-3 Unix machines at the time, doing this twice can "set the standard" that gets used for the rest of time.

Another example of how historic accidents become standards that never go way is described in this article: Understanding the bin, sbin, usr/bin , usr/sbin split

Linux Hard Disk Load – How to Monitor Hard Disk Load on Linux

You can get a pretty good measure of this using the iostat tool.

% iostat -dx /dev/sda 5

Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
sda               0.78    11.03    1.19    2.82    72.98   111.07    45.80     0.13   32.78   1.60   0.64

The disk utilisation is listed in the last column. This is defined as

Percentage of CPU time during which I/O requests were issued to the device (band-width utilization for the device). Device saturation occurs when this value is close to 100%.

Best Answer

Related Solutions

Freebsd – Why does slice C or slice 2 cover the entire disk

Linux Hard Disk Load – How to Monitor Hard Disk Load on Linux

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