2 .\" Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
3 .\" This file may be copied under the terms of the GNU Public License, v2.
5 .TH llverdev 8 "2008 Mar 15" Lustre "configuration utilities"
7 llverdev - verify a block device is functioning properly over its full size
15 .RB [ -l "] [" -p "] [" -r ]
21 Sometimes kernel drivers or hardware devices have bugs that prevent them from
22 accessing the full device size correctly, or possibly have bad sectors on disk
23 or other problems which prevent proper data storage. There are often defects
24 associated with major system boundaries such as 2^32 bytes, 2^31 sectors,
25 2^31 blocks, 2^32 blocks, etc.
29 tool will write and verify a unique test pattern across the entire device in
30 order to ensure that not only is data accessible after it was written, but
31 also that data written to one part of the disk is not overwriting data on
32 another part of the disk.
34 It is expected that llverdev tool will be run on large size devices (TB),
35 so it is always better to run llverdev tool in verbose mode, so that one
36 can easily restart device testing from the point at which it had stopped.
38 Running a full verification can be time consuming for very large devices,
39 so it is advisable to start with a partial verification to ensure the
40 device is minimally sane before investing the time in a full verification.
44 IO chunk size in bytes (default=1048576).
47 force test to run without confirmation that the device will be overwritten
48 and all data therein will be permanently destroyed.
51 display a brief help message.
54 offset in kilobytes of start of test (default=0).
57 Run a full check, writing and then reading and verifying every block on the
61 Run a partial check, only doing periodic checks across the device (1GB steps).
64 Run test in read (verify) mode only, after having run the test in
69 Set test start time as printed at the start of a previously interrupted test
70 to ensure that the validation data is the same across the whole filesystem
71 (default=current time())
74 Run test in verbose mode, listing each read and write operation.
77 Run test in write (test-pattern) mode (default run both read and write)
80 Run a partial device verification on \fB/dev/sda\fR:
81 .B llverdev -v -p /dev/sda
83 llverdev: permanently overwrite all data on /dev/sda (yes/no)? y
85 llverdev: /dev/sda is 4398046511104 bytes (4096.0 GB) in size
89 Current write offset: 4096 kB
91 Continue an interrupted verification at offset \fB4096\fRkB from the start of the device, using the same timestamp as the previous run:
92 .B llverdev -f -v -p --offset=4096 --timestamp=1009839028 /dev/sda
94 llverdev: /dev/sda is 4398046511104 bytes (4096.0 GB) in size