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| 6 | <title>Fixing problems with corruption on the server</title> |
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| 13 | <img src="images/bblogo.png" alt="logo" height="65" width="331" border="0" vspace="5" align="middle" /> <img src="images/stepahead.png" alt="a step ahead in data security" width="182" height="11" hspace="10" vspace="20" border="0" align="middle" /></div> |
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| 16 | |
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| 17 | <h1>Fixing problems with corruption on the server</h1> |
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| 18 | |
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| 19 | <p>This page gives help on what to do if your server has suffered corruption, for example, |
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| 20 | after an unclean shutdown or other OS or hardware problem.</p> |
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| 21 | |
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| 22 | <p>In general, as updates to the store are made in an atomic manner, the most |
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| 23 | likely result is wasted disc space. However, if really bad things happen, or you believe that |
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| 24 | there is a lot of wasted space, then these instructions will help to restore your data.</p> |
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| 25 | |
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| 26 | <p>You know you will need to do something if you get strange errors, and <tt>bbackupd</tt> attempts |
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| 27 | to contact the server every 100 seconds or so. Or if one of the discs in your RAID disc set has failed.</p> |
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| 28 | |
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| 29 | <p>After following these instructions, the end result will be that <tt>bbackupquery</tt> will be able to see all the files which |
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| 30 | were stored on your server, and retrieve them. Some of them may be in <tt>lost+found</tt> |
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| 31 | directories in the root of the store (or in their original position if they have been moved) but they will all |
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| 32 | be able to be retrieved.</p> |
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| 33 | |
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| 34 | <p>After you have retrieved the files you want, <tt>bbackupd</tt> will upload new versions |
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| 35 | where necessary, and after about two days, mark any <tt>lost+found</tt> directories as deleted. |
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| 36 | Finally, those directories will be removed by the housekeeping process on the server.</p> |
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| 37 | |
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| 38 | <p>These instructions assume you're working on account 1234, subsitute this for whatever account |
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| 39 | you're actually working on. These will need to be repeated for all affected accounts.</p> |
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| 40 | |
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| 41 | <h2>1. Stop bbackupd</h2> |
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| 42 | |
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| 43 | <p>First, make sure that <tt>bbackupd</tt> is not running on the client machine for the account |
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| 44 | you are going to recover. Use <tt>kill</tt> to terminate it.</p> |
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| 45 | |
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| 46 | <p>(This step is not strictly necessary, but is recommended. During any checks on the account, |
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| 47 | <tt>bbackupd</tt> will be unable to log in, and after they are complete, the account is marked |
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| 48 | as changed on the server so <tt>bbackupd</tt> will perform a complete scan.)</p> |
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| 49 | |
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| 50 | <h2>2. Are you using RAID on the server?</h2> |
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| 51 | |
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| 52 | <p>At the moment, the raidfile recovery tools have not been written. However, when two out of |
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| 53 | three files are available, the server will run succesfully, even if it complains a lot in the logs. |
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| 54 | So, your best bet here is to fix the accounts, if necessary, and retrieve any files you need. Then move |
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| 55 | the old store directories aside (in case you need them) and start afresh with new accounts, and |
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| 56 | let the clients upload all their data again.</p> |
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| 57 | |
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| 58 | <p>These utilities will be written shortly!</p> |
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| 59 | |
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| 60 | <h2>3. Check and fix the account</h2> |
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| 61 | |
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| 62 | <p>First, run the check utility, and see what errors it reports.</p> |
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| 63 | |
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| 64 | <pre> |
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| 65 | /usr/local/bin/bbstoreaccounts check 1234 |
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| 66 | </pre> |
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| 67 | |
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| 68 | <p>This will take some time, and use a fair bit of memory (about 16 bytes per file and directory). |
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| 69 | If the output looks plausible and reports errors which need fixing, run it again but with the |
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| 70 | <tt>fix</tt> flag:</p> |
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| 71 | |
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| 72 | <pre> |
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| 73 | /usr/local/bin/bbstoreaccounts check 1234 fix |
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| 74 | </pre> |
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| 75 | |
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| 76 | <p>This will fix any errors, and remove unrecoverable files. Directories will be recreated if necessary.</p> |
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| 77 | |
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| 78 | <p><b>NOTE</b>: The utility may adjust the soft and hard limits on the account to make sure that |
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| 79 | housekeeping will not remove anything -- check these afterwards.</p> |
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| 80 | |
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| 81 | <h2>4. Grab any files you need with bbackupquery</h2> |
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| 82 | |
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| 83 | <p>At this point, you will have a working store. Every file which was on the server, and wasn't corrupt, |
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| 84 | will be available.<p> |
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| 85 | |
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| 86 | <p>On the client, use <tt>bbackupquery</tt> to log in and examine the store. (type <tt>help</tt> at the |
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| 87 | prompt for instructions). Retrieve any files you need, paying attention to any <tt>lost+found</tt> |
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| 88 | directories in the root directory of the store.</p> |
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| 89 | |
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| 90 | <p>You can skip this step if you are sure that the client machine is fine -- in this case, <tt>bbackupd</tt> |
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| 91 | will bring the store up to date.</p> |
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| 92 | |
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| 93 | <h2>5. Restart bbackupd</h2> |
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| 94 | |
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| 95 | <p>Restart <tt>bbackupd</tt> on the client machine. The store account will be brought up to date, and |
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| 96 | files in the wrong place will be marked for eventual deletion.</p> |
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| 97 | |
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| 98 | |
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| 99 | <p> </p> |
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| 100 | <p>© Ben Summers, 2003, 2004</p> |
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| 101 | <p> </p> |
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| 102 | </div> |
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| 103 | </div> |
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| 104 | </body> |
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| 105 | </html> |
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