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Cannot Read Flashcache Superblock

This is to make sure that the flashcache device can be mounted on /home on boot. I ve lot of data n desperately need to retrieve them..Thanks, Ashwin Reply Link mahendra September 1, 2010, 2:56 pmGood and simple. How did you manage to do it? Luckily the developers of Flashcache have been smart enough to implement this feature. this contact form

Obviously i don't know ext3 filesystem internals -- too much to learn, so little time… My point is: would there be any value in storing the list of superblock locations offline?Thanks, Successfully recovered my data, and with much less stress than I might have had due to the clear explanations. Can someone give an example ? over 2 years Allow separation of skip_seq_thresh_kb over 2 years LVM not cached after reboot over 2 years Kernel panic on latest CentOS 6 VZKernel over 2 years Won't compile after https://github.com/facebookarchive/flashcache/blob/master/src/utils/flashcache_load.c

Terms Privacy Security Status Help You can't perform that action at this time. Flashcache has been developed and released by Facebook which uses the module to speed up their database servers. In the 'flashcache' directory that has just been created you need to use the 'make' command to compile the source The make command compiles both the module and all the tools Other options: [-nfFrsvw] [-o options] [-p passwdfd].

This is easier to do and no overhead during normal operation. Succesvol Open Source. over 2 years not sure if this is a flashcache issue; performance issue (slow IO, high load, high iowait) almost 3 years Advices for performance tuning almost 3 years Flashcache write_back This piece of blog is solid gold.

Reply Link nixCraft December 28, 2009, 11:33 [email protected] maxYou can.. I have accidently run fsck on a corrupted umounted file system without taking back up. Trying to reiterate restoring the superblock with fsck didn't help. https://github.com/facebookarchive/flashcache/issues/165 If you are old school UNIX person, tar, dump and restore are regular tools for backup.HTH Reply Link Evan January 3, 2010, 2:39 amthank you so much, this is valuable information,

Close all applications running and unmount: # umount /home After the unmount has finished I can create the flashcache device, this is done with the flashcache_create utility which works in the Reply Link JW0914 April 28, 2015, 4:18 pmif using mount command on BSD OSs (FreeBSD, FreeNAS, etc), you will always receive the error in the OP as it's not the proper Even after i run d command i m gettin a ‘couldnt find ext2 superblock. Already have an account?

This is to make sure that even if the order of devices are changed that the flashcache device can be build by using the UUID. http://blog.gerrit-tamboer.net/using-flashcache-to-speed-up-your-io-on-ubuntu-12-04/ and of course, your big files you often work with. Reply Link midgard July 25, 2013, 5:57 pmAlso you can use mkfs command, for example for ext4 fs:mkfs.ext4 -n /dev/XX Reply Link uncle max December 28, 2009, 7:06 amHi, this looks Worked Perfectly on RHEL5 Reply Link Phillip October 7, 2009, 5:10 pmWorked perfectly under RHEL5.

This can be done by using the modprobe command. # modprobe flashcache By checking out your kernel messages you can see that it has been initialized. # dmesg | tail ............................. weblink You signed out in another tab or window. Every option is well documented! and was hit by same issue.

Only writeback cache has a superblock. Have fun testing! I believe we will be able to mount the fs using a diff super block "only" if we r running system in rescue mode with cd media mounted, I could not navigate here Does using a extended cache (readyboost-like) improves the overall performance?

Een kijkje in de keuken bij Shock Media » Leave a Reply Cancel reply Your email address will not be published. ssd bcache asked Nov 8 '12 at 23:18 user106561 1112 2 votes 1answer 6k views “Device not found or ignored” when creating physical volume with bcache I'm attempting to create an Also, I've the following other outputs executed in the sequence as displayed [[email protected] boopathi]# flashcache_load /dev/md127 /dev/mapper/cachedev flashcache_load: Invalid Flashcache superblock /dev/md127 [[email protected] boopathi]# flashcache_destroy /dev/md127 flashcache_destroy: No valid Flashcache found

Reply Link Dean October 23, 2012, 10:37 pmNice!

Even the cache would always be clean, it may contain lot of data read from drives from previous run time - kde, netbeans... You signed out in another tab or window. I want to know if there is any command by that I can know the size of the file system before and after fsck run. Reply Link Phillip October 7, 2009, 5:06 pmAwesome.

You signed in with another tab or window. Only one issue. So, how can I know which is the partition with a broken superblock? http://sauvblog.com/cannot-read/cannot-read-usr.html boopathi commented Mar 14, 2013 #Possible Fix.

Indeed this is a great shortcut - mke2fs -n /dev/XX .Thank you for suggesting this.This is a wonderful website with easy to understand and clear text linux resource. Reply Link Rajan September 25, 2014, 6:33 amThanks for the nice article. But there must be a logical reason to purposely omit the persistence across restarts. At boot: prompt type command linux rescue).Mount partition using alternate superblockFind out superblock location for /dev/sda2: # dumpe2fs /dev/sda2 | grep superblock Sample output: Primary superblock at 0, Group descriptors at

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