I want to make an index for +480 million of rows but everytime I
try it give me some error.
row: {
"_id": 106530507294121984,
"userid": 290864368,
"inreply": 0,
"ts": 1314233826,
"lang": "es",
"fonum": 80,
"frnum": 68,
"crts": 1314234007,
"geolng": 0,
"geolat": 0,
"text": "RT @realmadrid: Hoy se celebra el sorteo de la fase de
grupos de la Champions League http:\/\/t.co\/gyqd2Il #realmadrid",
"_keywords":

{ "1": "@realmadrid", "4": "celebra", "6": "sorteo", "9": "fase", "11": "grupos", "14": "champions", "15": "league", "16": "t.co\/gyqd2il", "17": "#realmadrid" }

}

index:
db.tweets.ensureIndex({_keywords:1,ts:1});
I use debian squeeze and mongodb from apt:
root@xxxx:~# apt-cache show mongodb-10gen
Package: mongodb-10gen
Version: 1.8.3
Architecture: amd64
root@ks27931:~# uname -a
Linux xxxx 2.6.38.2-grsec-xxxx-grs-ipv6-64 #1 SMP Fri Apr 15 17:44:15
UTC 2011 x86_64 GNU/Linux
root@ks27931:~# free -m
total used free shared buffers
cached
Mem: 24146 23201 945 0 16
22165
-/+ buffers/cache: 1018 23127
Swap: 7998 0 7998
mongo-db.log:
Mon Aug 29 19:35:00 [conn1] finishing map
483235400/483550704 99%
Mon Aug 29 19:35:10 [conn1] finishing map
Mon Aug 29 19:35:14 [conn1] external sort used : 911 files in
4840 secs
Mon Aug 29 19:35:14 [conn1] couldn't open /var/lib/mongodb/_tmp/esort.
1314634473.1391960871//file.899 errno:24 Too many open files
Mon Aug 29 19:35:14 [conn1] Assertion: 10308:mmap failed
0x55f39a 0x7a7927 0x7ab31e 0x778fbc 0x779eca 0x77b90b 0x7826df
0x75bccf 0x75d8fc 0x8ae1de 0x7f456834d8ba 0x7f456790902d
/usr/bin/mongod(_ZN5mongo11msgassertedEiPKc+0x12a) [0x55f39a]
/usr/bin/mongod(_ZN5mongo21BSONObjExternalSorter12FileIteratorC1ESs
+0xe7) [0x7a7927]
/usr/bin/mongod(ZN5mongo21BSONObjExternalSorter8IteratorC1EPS0
+0x13e) [0x7ab31e]
/usr/bin/
mongod(_ZN5mongo14fastBuildIndexEPKcPNS_16NamespaceDetailsERNS_12IndexDetai lsEi
+0xddc) [0x778fbc]
/usr/bin/mongod() [0x779eca]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb
+0xf4b) [0x77b90b]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr16insertWithObjModEPKcRNS_7BSONObjEb
+0x5f) [0x7826df]
/usr/bin/mongod(_ZN5mongo14receivedInsertERNS_7MessageERNS_5CurOpE
+0x35f) [0x75bccf]
/usr/bin/
mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8Sock AddrE
+0x195c) [0x75d8fc]
/usr/bin/mongod(_ZN5mongo10connThreadEPNS_13MessagingPortE+0x21e)
[0x8ae1de]
/lib/libpthread.so.0(+0x68ba) [0x7f456834d8ba]
/lib/libc.so.6(clone+0x6d) [0x7f456790902d]
Mon Aug 29 19:35:14 terminate() called, printing stack:
0x8ac5ad 0x7f45680fe166 0x7f45680fd059 0x7f45680fdb01 0x7f4567bab7f3
0x7f4567bab8b8 0x7a83d8 0x779710 0x779eca 0x77b90b 0x7826df 0x75bccf
0x75d8fc 0x8ae1de 0x7f456834d8ba 0x7f456790902d
/usr/bin/mongod(_ZN5mongo11myterminateEv+0x4d) [0x8ac5ad]
/usr/lib/libstdc++.so.6(+0xcb166) [0x7f45680fe166]
/usr/lib/libstdc++.so.6(+0xca059) [0x7f45680fd059]
/usr/lib/libstdc++.so.6(__gxx_personality_v0+0x261) [0x7f45680fdb01]
/lib/libgcc_s.so.1(+0x107f3) [0x7f4567bab7f3]
/lib/libgcc_s.so.1(_Unwind_Resume+0x68) [0x7f4567bab8b8]
/usr/bin/mongod(_ZN5mongo21BSONObjExternalSorterD1Ev+0x1a8)
[0x7a83d8]
/usr/bin/
mongod(_ZN5mongo14fastBuildIndexEPKcPNS_16NamespaceDetailsERNS_12IndexDetai lsEi
+0x1530) [0x779710]
/usr/bin/mongod() [0x779eca]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb
+0xf4b) [0x77b90b]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr16insertWithObjModEPKcRNS_7BSONObjEb
+0x5f) [0x7826df]
/usr/bin/mongod(_ZN5mongo14receivedInsertERNS_7MessageERNS_5CurOpE
+0x35f) [0x75bccf]
/usr/bin/
mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8Sock AddrE
+0x195c) [0x75d8fc]
/usr/bin/mongod(_ZN5mongo10connThreadEPNS_13MessagingPortE+0x21e)
[0x8ae1de]
/lib/libpthread.so.0(+0x68ba) [0x7f456834d8ba]
/lib/libc.so.6(clone+0x6d) [0x7f456790902d]
Mon Aug 29 19:35:14 Got signal: 6 (Aborted).
Mon Aug 29 19:35:14 Backtrace:
0x8ad399 0x7f456786c1e0 0x7f456786c165 0x7f456786ef70 0x8ac67b
0x7f45680fe166 0x7f45680fd059 0x7f45680fdb01 0x7f4567bab7f3
0x7f4567bab8b8 0x7a83d8 0x779710 0x779eca 0x77b90b 0x7826df 0x75bccf
0x75d8fc 0x8ae1de 0x7f456834d8ba 0x7f456790902d
/usr/bin/mongod(_ZN5mongo10abruptQuitEi+0x399) [0x8ad399]
/lib/libc.so.6(+0x321e0) [0x7f456786c1e0]
/lib/libc.so.6(gsignal+0x35) [0x7f456786c165]
/lib/libc.so.6(abort+0x180) [0x7f456786ef70]
/usr/bin/mongod(_ZN5mongo11myterminateEv+0x11b) [0x8ac67b]
/usr/lib/libstdc++.so.6(+0xcb166) [0x7f45680fe166]
/usr/lib/libstdc++.so.6(+0xca059) [0x7f45680fd059]
/usr/lib/libstdc++.so.6(__gxx_personality_v0+0x261) [0x7f45680fdb01]
/lib/libgcc_s.so.1(+0x107f3) [0x7f4567bab7f3]
/lib/libgcc_s.so.1(_Unwind_Resume+0x68) [0x7f4567bab8b8]
/usr/bin/mongod(_ZN5mongo21BSONObjExternalSorterD1Ev+0x1a8)
[0x7a83d8]
/usr/bin/
mongod(_ZN5mongo14fastBuildIndexEPKcPNS_16NamespaceDetailsERNS_12IndexDetai lsEi
+0x1530) [0x779710]
/usr/bin/mongod() [0x779eca]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr6insertEPKcPKvibRKNS_11BSONElementEb
+0xf4b) [0x77b90b]
/usr/bin/
mongod(_ZN5mongo11DataFileMgr16insertWithObjModEPKcRNS_7BSONObjEb
+0x5f) [0x7826df]
/usr/bin/mongod(_ZN5mongo14receivedInsertERNS_7MessageERNS_5CurOpE
+0x35f) [0x75bccf]
/usr/bin/
mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_8Sock AddrE
+0x195c) [0x75d8fc]
/usr/bin/mongod(_ZN5mongo10connThreadEPNS_13MessagingPortE+0x21e)
[0x8ae1de]
/lib/libpthread.so.0(+0x68ba) [0x7f456834d8ba]
/lib/libc.so.6(clone+0x6d) [0x7f456790902d]
Mon Aug 29 19:35:14 dbexit:
Mon Aug 29 19:35:14 [conn1] shutdown: going to close listening
sockets...
Mon Aug 29 19:35:14 [conn1] closing listening socket: 5