RAID1
In some configurations it might be desired to create a raid1
configuration that does not use a superblock, and to maintain the state of
-the array elsewhere. While not encouraged for general us, it does
+the array elsewhere. While not encouraged for general use, it does
have special-purpose uses and is supported.
.SS ARRAYS WITH EXTERNAL METADATA
From release 2.6.28, the
.I md
driver supports arrays with externally managed metadata. That is,
-the metadata is not managed by the kernel by rather by a user-space
+the metadata is not managed by the kernel but rather by a user-space
program which is external to the kernel. This allows support for a
variety of metadata formats without cluttering the kernel with lots of
details.
.I md
is able to communicate with the user-space program through various
sysfs attributes so that it can make appropriate changes to the
-metadata \- for example to make a device as faulty. When necessary,
+metadata \- for example to mark a device as faulty. When necessary,
.I md
will wait for the program to acknowledge the event by writing to a
sysfs attribute.
threads to read from all disks.
Individual devices in a RAID1 can be marked as "write-mostly".
-This drives are excluded from the normal read balancing and will only
+These drives are excluded from the normal read balancing and will only
be read from when there is no other option. This can be useful for
devices connected over a slow link.
found that is a mismatch.
.I md
normally works in units much larger than a single sector and when it
-finds a mismatch, it does not determin exactly how many actual sectors were
+finds a mismatch, it does not determine exactly how many actual sectors were
affected but simply adds the number of sectors in the IO unit that was
used. So a value of 128 could simply mean that a single 64KB check
found an error (128 x 512bytes = 64KB).
This is the partner of
.B md/sync_speed_min
and overrides
-.B /proc/sys/dev/raid/spool_limit_max
+.B /proc/sys/dev/raid/speed_limit_max
described below.
.TP