Btrfs the new generation Linux file system

Todays storage system is scaling up from gigabytes to terabytes to petabytes all the way to exabytes. As a result, file systems need to scale in their ability to address and manage large storage, and also in their ability to detect, repair and tolerate errors in the data stored on the disk.

Announced by Chris Mason of Oracle in 2007, Btrfs (pronounced as "Butter FS") is a new generation of copy on write, snapshoting file system for Linux aims to replace the ext3 file system (the most commonly used file system in Linux nowadays) while removing a number of its limitations, particularly with respect to file size and total file system size.

The distinctive features of Btrfs include:

• Extent based file storage (2⁶⁴ maximum file size)
• Space-efficient packing of small files and indexed directories
• Dynamic inode allocation (no maximum number of files set at file system creation time)
• Writable snapshots
• Subvolumes (separate internal filesystem roots)
• Object-level mirroring and striping
• Checksums on data and metadata (multiple algorithms available)
• Strong integration with device mapper for multiple device support
• Online filesystem check and very fast offline filesystem check
• Efficient incremental backup and file system mirroring
  

Btrfs is licensed under the GPL and open for contribution from anyone. Currently it is still under heavy development, with Version 1.0 planned to release by 4th quarter of 2008.

Here are some of the benefits of Btrfs:

• Support for large storage, with maximum file size up to 16 EiB, maximum number of files is 2⁶⁴ and maximum volume size is 16 EiB.
• Ultra fast copy-on-write system which is capable of quickly creating snapshots of the state of the filesystem at any time.
• Online resizing possible to change the size of the file system while it is mounted and busy, such as shrinking the file system.
• Storage pools enabling the file system to span multiple devices.

So how can you be benefited from this new generation of file system? Perhaps you can get a faster Internet search result, more reliable banking data, and more robust stock exchange system. (Remember what happened to Bursa Malaysia on 3 July 2008 when their system faced a storage system faulty?)

Mastercard Malaysia Mega Sale Promotion 2008

If you have a Mastercard, be it credit card, debit card, prepaid card or Electronic card, and none of your immediate family members is employee of Mastercard, paticipating banks, auditors and/or advertising agents of Mastercard, every swipe of your Mastercard done within Malaysia between 5 July 2008 to 1 September 2008 could bring you a fortune.

The MasterCard Malaysia Mega Sale Promotion 2008 is organized by Tourism Malaysia with support from MasterCard as the official card for the promotion for all MasterCard cardholders who charge their purchases within Malaysia during the promotion period (from 5 July 2008 to 1 September 2008). It is not necessary for the Mastercard itself to be issued in Malaysia in order to get the participation.

There are altogether 6 prizes for 6 winners only:

• A Grand Prize of RM50,000
• 5 Secondary Prizes of RM10,000 each

The winners will be selected from transactions made during the promotion period. Only the millionth transactions will be short-listed as qualifying entries for the contest, i.e. the 1,000,000th, 2,000,000th, 3,000,000th transaction for the entire promotion period, to which 6 cardholders with the highest value transactions made during the promotion period will be contacted by the promoter.

The cardholders must then correctly answer the questions posed to them before they may win the prizes. The cardholder who answers the questions correctly and who had the qualifying entry made from the highest value transaction will be the Grand Prize winner. The remaining 5 cardholders who answer the questions correctly will be the Secondary Prizes winners.

Seems like it is not easy to win the prize although it is pretty easy to participate. The draw will be conducted in the office of MasterCard Asia/Pacific Pte. Ltd. on 22 September 2008.

Lesson learnt - what happen if bank account gone -ve balance

Recently, I've learnt a good lesson which cost me RM5, due to my bank account gone negative balance caused by miscalculation and wrong timing judgement. Luckily it was immediately discovered via Internet banking, and quickly rectified. If not it will cost more, and possibly will result in bounce cheque and penalty.

The story began when I discovered the troubled bank account balance has become RM-34.00 on 30 June. That was because it has a shortfall of RM29.00 and an immediate penalty "interest charged" of RM5.00 [indicator (2)].

The root cause:

I issued some cheques, calculated that the account will still have a balance of hundred over ringgit after all the cheques were cleared. However, I forgotten about a scheduled credit card payment with amount of hundred over ringgit [indicator (3)] which was slightly more than the remaining balance after all the cheques were cleared then.

I thought that would not be a problem, because I have another cheque banked in to the account, which suppose to be cleared on the same day [indicator (5)]. But due to "some technical problem" as explained by the bank's cheque clearing officer, that cheque clearance was delayed by one day, and hence causing my bank account to be in trouble with a negative balance.



To rectify the problem once discovered, I immediately transferred RM50.00 from my other account with the same bank to make the balance changed from the RM-34.00 back to RM16.00. Then, I quickly called up the bank, and was informed that one of my issued cheques [indicator (1)] did not have sufficient fund to clear out, and was advised to put in an additional RM100 to avoid that cheque from bouncing back. So I tranfered another RM100.00 to the account [indicator (4)].

The next day, I noticed 2 lines appeared in the statement [indicator (6)]. There was a "cheque repair credit" immediately followed by another "cheque repair debit". Luckily, that cheque [indicator (1)] still gone through and cleared.

Lesson learnt:

• Always check for the "future payment" and "future transfer" sections for scheduled payment made earlier, to ensure the account balance is sufficient to draw out money from it.
• Don't take for granted that the bank-in cheque will be cleared on time. The banked in amount can only be used after the cheque is cleared and the amount is made available to use in the account. Good news is, all the banks will use a new clearing system beginning 1 July 2008, which will shorten the time required to clear all the cheque transactions.