raid reconstruction speed

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




	Sorry for flooding ;)

	I have the following configuration :
	- two disks (hda and sda)
	- each disk has 2 partitions (hda1/sda1) and (hda2/sda2)
	- two raid1 md devices are made :
	md0 = sda1 + hda1, contains the OS
	md1 = sda2 + hda2, contains a database

	I made 2 devices because I wanted to use different FS's.

When rebuilding md1, it does not realize accesses to md0 wait for the same disks. Thus reconstruction of md1 runs happily at full speed, and the machine is dog slow, because the OS and everything is on md0. (I cat /dev/zero to a file on md1 to slow the rebuild so it would let me start a web browser so I don't get bored to death)

When rebuilding md0, the rebuild process detects accesses to md0 and behaves nicely (the machine is responsive). However, it does not realize that md1 is on the same disks, thus the databases are dog slow.

Fortunately, as the rebuild runs ar full speed, the pain does not last long. It took 5 minutes to start this email client though.
	Thought you might wanna know ;)

	Regards,

	Pierre Caillaud
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux