[General Questions and Answers] BarrySamuels:
LG Optimus 2x (P990), Stock ROM, Android 2.3.4, rooted, ROM Manager and CWM Recovery installed.

My phone seemed to be getting rather slow so I decided to clear the cache and the Dalvik cache, from the recovery menu, to see if it would speed up the phone a little. Both processes completed without errors and I rebooted the phone.

The phone now works faster and is completely normal except for one thing. I find that I cannot now download any apps from Google Play as I get an error 498. If I look at a DF listing in a terminal there is no /cache listed. If I look at the results of 'mount' in the terminal I cannot see a cache partition either.

I have tried clearing the cache 3 times now with no success. I have also tried Cache Fixer but that gives errors if I try to move the cache 'Cache has NOT been moved'. I assume that may be because there isn't a cache partition now. I also tried restoring the cache using a partial restore from a nandroid backup which completed successfully but hasn't cured the problem - I still don't seem to have a cache.

EDIT: I've just had a look at the partition using fdisk and this is what I see:

Disk /dev/block/mmcblk0p2: 4 heads, 16 sectors, 2048 cylinders

Nr AF Hd Sec Cyl Hd Sec Cyl Start Size ID

1 00 0 0 0 0 0 0 0 0 00

2 00 0 0 0 0 0 0 0 0 00

3 00 0 0 0 0 0 0 0 0 00

4 00 0 0 0 0 0 0 0 0 00

Doesn't look good!

FURTHER EDIT: That bit about fdisk above is wrong. I thought that I was looking at a device but it was a partition.

Using fdisk on the proper device I get:

Disk /dev/block/mmcblk0: 7996 MB, 7996440576 bytes

1 heads, 16 sectors/track, 976128 cylinders

Units = cylinders of 16 * 512 = 8192 bytes

Device Boot Start End Blocks Id System

/dev/block/mmcblk0p1 129 44928 358400 83 Linux

Partition 1 does not end on cylinder boundary

/dev/block/mmcblk0p2 44929 53120 65536 83 Linux

Partition 2 does not end on cylinder boundary

/dev/block/mmcblk0p3 53121 53376 2048 83 Linux

Partition 3 does not end on cylinder boundary

/dev/block/mmcblk0p4 53377 946432 7144448 5 Extended

Partition 4 does not end on cylinder boundary

/dev/block/mmcblk0p5 53441 54464 8192 83 Linux

/dev/block/mmcblk0p6 54529 54848 2560 83 Linux

/dev/block/mmcblk0p7 54913 57472 20480 83 Linux

/dev/block/mmcblk0p8 57537 254144 1572864 83 Linux

/dev/block/mmcblk0p9 254209 946432 5537792 83 Linux

So the cache partition is still there (/dev/block/mmcblk0p2) but it doesn't appear in the mount list:

rootfs / rootfs ro,noatime 0 0

tmpfs /dev tmpfs rw,relatime,mode=755 0 0

devpts /dev/pts devpts rw,relatime,mode=600 0 0

proc /proc proc rw,relatime 0 0

sysfs /sys sysfs rw,relatime 0 0

none /acct cgroup rw,relatime,cpuacct 0 0

tmpfs /mnt/asec tmpfs rw,noatime,mode=755,gid=1000 0 0

tmpfs /mnt/obb tmpfs rw,noatime,mode=755,gid=1000 0 0

none /dev/cpuctl cgroup rw,relatime,cpu 0 0

/dev/block/mmcblk0p1 /system ext3 ro,nodev,noatime,data=ordered 0 0

/dev/block/mmcblk0p8 /data ext3 rw,nosuid,nodev,noatime,data=ordered 0 0

tmpfs /mnt/extasec tmpfs rw,nodev,noatime,mode=755,gid=1000 0 0

/dev/block/mmcblk0p6 /lgdrm ext3 rw,nosuid,nodev,relatime,data=ordered 0 0

/dev/block/vold/179:9 /mnt/sdcard vfat rw,dirsync,nosuid,nodev,noexec,noatime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

/dev/block/vold/179:9 /mnt/secure/asec vfat rw,dirsync,nosuid,nodev,noexec,noatime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

tmpfs /mnt/sdcard/.android_secure tmpfs ro,relatime,size=0k,mode=000 0 0

/dev/block/vold/179:17 /mnt/sdcard/_ExternalSD vfat rw,dirsync,nosuid,nodev,noexec,noatime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

/dev/block/vold/179:17 /mnt/extsecure/extasec vfat rw,dirsync,nosuid,nodev,noexec,noatime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

tmpfs /mnt/sdcard/_ExternalSD/.android_secure tmpfs ro,relatime,size=0k,mode=000 0 0

/dev/block/dm-0 /mnt/asec/com.MultitaskingDrawer-2 vfat ro,dirsync,nosuid,nodev,noatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

/dev/block/dm-1 /mnt/asec/org.englishheritage.app-2 vfat ro,dirsync,nosuid,nodev,noatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

/dev/block/dm-2 /mnt/asec/uk.agiletech.forestcomm-2 vfat ro,dirsync,nosuid,nodev,noatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

/dev/block/dm-3 /mnt/asec/com.mxdata.tube.Market-1 vfat ro,dirsync,nosuid,nodev,noatime,uid=1000,fmask=0222,dmask=0222,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

If I try and unmount, mount or remount the cache partition I get 'Invalid argument'.

I have run a file system check on that partition and it shows 'clean'. So, to summarise, the cache partition is there, the file system is clean but it isn't being mounted and I can't mount it either. I'm baffled.

I would be really grateful for some suggestions.