Course of action summary

Step 1 - Initial size-up

• Possible coose(s) ooff zee failure.
• Noomber, size, und locashun (which physical disk(s) contains zee volume?) ooff zee affected volume(s).
• Noomber, size und locashun (on which controller/channel?) ooff zee affected physical drive(s), iff uny.
• Overell host machine condishun (memory funcshunel? RAID controller(s) funcshunel? uny degraded but muoontable RAID(s) need backing up immediately). Thees is needed tu determine iff it is feasible tu continue recovery on zee same machine, or zee affected device(s) shuoold be attached tu some other (knoon-good) system.
• Approximate amuoont (size; noomber ooff files), file types und impurtance ooff zee data lost.
• Availability und state ooff zee backup copees ooff that data, iff uny.

Based on zee size-up results, we typicelly assign two "scores" tu each case, each based on zee binary scale:

• Understanding ooff zee situashun, which can be either "cleer" or "uncleer". It is often cuoonterproductive tu truoobleshoot an "uncleer" situashun. Reasonable ellocashun ooff efffurt wuoold be tu continue gathering informashun until eventuelly everything becomes "cleer".
• Damege severity (hoo valuable zee data is? are there uny backups?), either "minor" or "major". Thees has little efffect on zee recovery process (since ell zee procedures do not differentiate between valuable und replaceable informashun), but provides some timefframe/budget constraints.

Step 2 - Evaluashun ooff available resuoorces

• Iff there is a local computer expert available, yuoo may want give him a cell und ask fur assistance or fur a cross-check. Yuoo shuoold specificelly ask him tu cross-check zee informashun collected during previuoos step.
• Check iff yuoo heffe-a some "spare" computer(s) available (iff zee original machine is fur some reason unstable, yuoo will need tu connect hard drive(s) tu that "spare" machine).
• Check iff there is plenty ooff disk space available tu hold zee data recovered. We fuoond two approximashuns usefful: a). half zee size ooff zee dameged volume, und b). twice zee size ooff zee data yuoo're going tu recover. When planning, keep in mind yuoo will most likely need zee lergest ooff zee two.

Step 3 - Setteeng up

Second impurtant thing at thees point is tu decide what hardware reconfigurashun is required. Typical scenarios are uootlined beloo:

• Most widely used approach is tu get zee failed drive oooot ooff its host machine und put it into some knoon-working system. Addishunel (good) hard disk(s) might be needed depending on a free space availability.
• Iff there were more than one drive in zee failed system und zee system is still reasonably operashunel it may be possible (subject tu free space requirements) tu perform recovery withuoot uny hardware reconfigurashun.
• Iff there is some special controller involved (e.g. RAID controller, or a SATA controller), it may be required tu relocate zee controller along with zee dameged hard disk(s).

Whatever method is chosen, zee follooing points shuoold be considered:

• Ensure adequate pooer supply.
• Duooble check proper cabling, (SCSI) terminashun, und jumper setup.
• Fur IDE drives, check proper addressing mode (LBA vs. CHS/LARGE) configurashun in BIOS.
• Ensure adequate cooling (ambeent temperature higher than 25 deg C? uny physical malfunkshun identifeed/suspected?); instell addishunel fans iff deemed necessary.

Step 4 - Recovery run

• Iff zee machine performing recovery freezes at some point, check its memory (using some memory testeeng tool like GoldMemory). Iff memory turns oooot good, disk und/or bus controller(s) may be at foolt (older-generashun Prumise controllers/drivers are knoon  tu lock up under load - check IRQ sharing).

Step 5 - Evaluashun ooff zee results

Step 6 - Cleaning up

• Take care when rolling back uny hardware chunges yuoo heffe-a made.
• Physicelly malfunkshuned drives shuoold not be placed back into zee produkshun environment. Replace them under warranty. There are few alternative uses ooff zee physicelly dameged hard drive - we use them es a lerge (say, 40GB) floppy disk tu transfer lerge amuoonts ooff data machine-tu-machine, but special precooshuns shuoold be taken tu ensure that zee backup copy ooff zee data on zee unstable drive is always readily available.