Help needed! Got error 28 from storage engine

I'm running a small site elgg 1.7.1 version:2010040201

front page of site now showing the error message pasted below, no other pages will load, interestingly my dev site on same server also won't load, but is not showing any error message.   I don't have access to database until tomorrow when tech staff will be around, as they don't know the platform it may help if  I understood the message :

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Got error 28 from storage engine

QUERY: SELECT msv.string as tag, count(msv.id) as total FROM

elgg171_entities e JOIN elgg171_metadata md on md.entity_guid =

e.guid JOIN elgg171_metastrings msv on msv.id = md.value_id JOIN

elgg171_metastrings msn on md.name_id = msn.id WHERE msv.string

!= '' AND (msn.string IN ("tags","location","interests","skills")) AND

((e.type = 'object')) AND (e.site_guid IN (1)) AND ( (e.access_id IN (2)
OR (e.owner_guid = -1)
OR (
e.access_id = 0
AND e.owner_guid = -1
)
) and e.enabled='yes') GROUP BY msv.string HAVING total > 1 ORDER

BY total DESC LIMIT 20